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9
Mar

3D Printer Webcam

After doing some testing with webcams I’ve come to the conclusion that you need one wide-angle of a brute to get the job done without having to end up setting the webcam up 30+cm or more away from your print bed.

Awkward to say the least.

What I wanted was to put the camera on one of my delta’s towers and have it catch the whole print bed. Impossible.

I duplicated the setup on my bench so this is what it can see… The webcam, standard el cheapo USB version on the left edge, printed 50mm LED light housing sitting on a 220mm bed.

IMG 0966

Through the web cam, this is what I can see…

Webcam Normal

Ah yeah, that’s useful. More like a macro cam. I had to keep in mind that these are meant to sit on the top of your monitor or laptop and grab your happy smiling face for those online chats. Nothing more.

I couldn’t find a wide angle webcam but I did notice that a lot of eBay sellers had some “wide angle” lens attachments you could use on your cellphone to photograph wide angle scenes. Cheap enough, wasn’t worried about the quality, so I ordered one.

IMG 0969

The description:

fisheye:
Angle: 175°- 180°
Magnification: 0.33X
Lens Construction : 3 Element 3 Group
Max Diameter: 25mm
Length: 15mm
 
Wide Angle :
Angle: 130°
Magnification: 0.67X
Lens Construction : 2 Element 2 Group
Max Diameter: 20mm
Length: 11mm
 
Macro :
Magnification : 10X
Min Object distance : 10-15mm
Lens Construction : 1 Element 1 Group
Max Diameter: 20mm
Length: 15mm

The “wide angle” one is fairly useless but…the fisheye one hits the mark!

I merely held the one marked “Fisheye” in front of the webcam lens and got this:

Webcam Wideangle

Probably some edge distortion, but at least it covers a fair portion of the print bed compared to the standard webcam.

I plan on printing up a simple mount to fix it to the front the webcam.

While I’m at it, I should advise that if you get a web cam, make sure you get one that allows you to adjust the focal ring. I have a couple that are fixed focus and a pain to adjust, whereas most of the budget ones I have allow easy focus adjustment.

6
Mar

Kossel Rebuild Time!

At 2,380 hours, it was time for a major Kossel rebuild. The accuracy was suffering a bit more, not that it was ever 100% accurate in the first place.

Plus I’d used the other printer to design a whack of new parts that I needed to test out anyway…

Kossel Disassembly…

As Johnny Five says, “No Disassemble”…which, looking back now might have been good advice…course the other old saw goes, “If it’s not broken, you’re not trying hard enough”.

It took just over four hours to reduce Bullwinkle to frame parts and a cardboard box of screws, nuts, electronics, and add ons. I could see it was going to take a LOT longer to get it back together.

I was astounded at how loose the parts had gotten in two years. Some were merely finger tight. Like the stepper motor screws. Others like the frame screws felt like I used Lactate when I put it together.

IMG 2433

Missing is the box full of new printed parts. The majority of which I custom designed/modified at some point but never got around to testing. Nothing like an unproven design is there…

Bullwinkle Rebuild

I started with the top frame. My own design. There is a top so the 2020 open beam can’t slide all the way through, a mount for the limit switch and a guide to ensure the linear rail would be entered on the 2020 beam.

IMG 2434

The reason for the tall height (60mm) instead of the usual 20mm, is simple. To make the frame more rigid. If you look at the typical delta printers there are large double mounts on the base, but the top of the frame has a rather skimpy structure that is able to twist without a lot of effort.

The mounts I printed fit the 2020 beam like a glove. As in no play whatsoever. Plus as I said there is a top to them so the 2020 beam butts up against it.

IMG 2339

The top side of the mount:

IMG 2340

Next the bottom frame, pretty much standard for a delta except the bottom of the frame is again closed off so the 2020 beam can’t slide through.

IMG 2436

With the closed off areas top and bottom frame, the belts on the steppers actually pull the top and bottom frames together. If any of the frame screws work loose the belt tension will still hold it together. I see this as a good thing. Just untested at this point.

Once the frame was put together, I added the linear rails. Normally you wouldn’t build it this way because it’s harder to put the rails on. Easier to put the rails on the 2020 beam, then put the beam in the frame parts. But since I had designed linear guide alignments into the top frame, well, frame piece had to go on first.

For the bottom end stop, I redesigned a part to ensure alignment all the way down the 2020 beam.

IMG 2429

Next up I soldered in the wires for the top end switches.

IMG 2441

Finally as the day was ending I put the power supply hangers on the top frame, mounted the power supply and ran the 12Vdc wires (16 gauge for the heated bed, 18 gauge for the hot end) down the left beam, and 16 gauge wires for the power wires down the right beam. I enclosed all the wires in some nylon sheathing to keep them from chaffing and keep them neat.

IMG 2442

I found some Mendal “clips” on Thingiverse and printed up a dozen of them. They work great…

Adding in the Arduino and RAMPS 1.4 board I use my own custom sled design to hold those and it works nicely.

Kossel Assembly – Day 2

Since I was rebuilding, I also rebuilt the hot end and extruder. This, of course was going to come back to bite me in the butt, but I didn’t know it at the time.

For the wiring from the hot end down to the RAMPS, I had a thermistor, heating element, 12V fan wire, and variable fan cooling wires. I put them all in a sheath like the 12V and 110Vac wiring. To keep it all neat.

And it was time to test out a new fan setup. On the left you can see the original fan setup I used. Axial 4020 fans, same as the cooling one that runs all the time. And they do work but axial like to be mounted vertically or horizontal, not on a slant. Plus axials don’t like back pressure.

Hence the middle design of the 4020S blower fans. These work absolutely super! BUT, for the variable speed controller I use (a 12V PWM controller from eBay), I had a few fans that didn’t want to spin up unless the full 12Vdc was going to them.

Recently I came across some 4010 blower fans. I redesigned the housing for them and they work better when you want to get out near the edges of the print bed. Plus they weigh 40% less than the other two fan set ups. Win win. Sort of. These fans blow more air than the 4020 blower fans do and don’t like to go as slow. Always trade offs.

IMG 2416

Ultimately, now, I can say that there isn’t a huge advantage over the standard blower fan (4020) other than the weight or size. That doesn’t appear to affect anything as far as I can tell.

The next area I had redesigned was the bed mounts. Every delta I have seen has these tabbed mounts of some sort, with a clip/clamp on the top to hold the glass and heated build plate down. I’ve seen a lot of them made out of PLA. The glass transition point of PLA is lower than what you need to heat the bed up to if you’re printing ABS. Things can get a little squishy. I’d think.

I could have printed some out of ABS, but that stuff gives me such a headache I try to avoid it where I can. Unless it’s summer time and I can vent the shop. So I did the next best thing. I used some silicon (high temp RTV) on the heater.

Silicon Adhesive

Then I put a layer of cork on the bottom.

Cork Mount

Trimmed the outside with a box knife. Mounted the bed right on top of the 2020 beam with the mounts next to it. My logic was that the normal glass mounts could be tilted because of the beam so what difference would it make if the bed sat right on the beam? As it turns out, it works just fine.

Finally the whole thing was back together, levelled, and I was test printing…

IMG 2443

Fail – Opps

This is the part where I say that it’s working absolutely perfect and a 100% successful rebuild.

Except I’d be lying through my teeth if I did.

First thing I did was print a quick bookmark, which incidentally I’ve printed about 100 times because I know what to look for and it doesn’t take long to print…

IMG 2447

See a problem? Yeah. This has got extrusion written all over it. So..

  1. Too far above the bed for first layer? Nope.
  2. Hot end too cold? Nope.
  3. Extruder not putting enough PLA through? Nope ***
  4. Extruder Tension too low/High? Nope ***

Notice the “***”… yeah those are hint giveaways. I used the old extruder and I only replaced the spring in it. The drive gear on my extruder, an MK8 was actually worn to the point that the filament was slipping on it. So 2,380 hours and by sheer chance I rebuilt it at the same time it decided to quick working.

I grabbed one of my spares from my parts bin and within a few minutes, the old gear was gone and new one in it’s place.

MK8 Gear

And all was right? Not. Even. Close.

I had the extruder “clicks”. These appear when you’re trying to shove filament through the bowden tube faster than the little 0.4mm nozzle can let it get out. The extruder skips and clicks. So yeah it printed better but ugly too…

Take a look at the “fingers” on the bookmark and around the eyes at the blobs. Obviously something still amiss.

IMG 2449

But what? At this point, I’d like to say, it was the “A” thing. Except, it wasn’t. It was still a BUNCH of things…things I’d never encountered or even thought of before.

I don’t what made me do it, but I took the bowden tube out of the hot end, sent an M302 code to the printer, and told it to extrude 100mm of filament. I fully expected 100mm of filament. I got 104.7mm on average. Say what?

As it happens, these MK8 gear things are not all made the same. Mine was extruding more than the original worn out one. Some rapid math calc and I had a new step value to put in Marlin for the extruder.

And all was fixed? Nah. Like I said, multiple issues. Now I was squashing the filament so hard with the new spring it was binding. Ah HA! A quick and easy fix.

I loaded up some freshly opened filament, printed again. Finally getting much better…however…if you look at the bottom you’ll see a line of fill that shouldn’t really be there. It’s in the solid fill so I’m over extruding so the solid fill ended up on top of the solid file (Slic3r tends to fill all over so it can and does backfill on itself).

IMG 2445

Didn’t make any sense to me, so I grabbed the old extruder gear, popped it in the extruder, asked for 100mm and measured what I got. 98.4mm average.

In a lot of slicer programs they tell you to set the extrusion multiplier to .9 for PLA filament. Purely by accident when I built this one two years ago I’d plugged in the right steps to give me about .94 and it had worked. Right up to the point where it wore out.

My choices were either to correct this in the firmware, or do it in the slic3r I use. I did it in slic3r and all came out like this:

IMG 2446

Summary

I swear I spent more time troubleshooting this rebuild than I did just rebuilding it. I learned a whack in the process, grew some more grey hairs and stressed out trying to figure it out.

In the end, I got the printer working like it should, it’s more accurate than it was and it’s really nice to have it in one piece again.

But the old adage is true, when you spill something out of the bucket you’re going to need a bigger bucket to get it all back in.

10
Feb

Soldering Gear

Soldering

A word that can strike mind numbing fear into first timers. I kind of remember learning how to do it, from a ham radio operator no less. Frustration for me, laughter for him. When I was 10 years old.

Now admittedly most parents wouldn’t dream of letting their 10 year old grab hold of a hot soldering iron because, well, they’re kids. And you never know what could happen.

Fortunately I was born in an era that believed if you grabbed something hot and burned yourself, you instantly gained the experience to never do that again. My parents bought me a wood burning kit for Xmas when I was 10, and with it came the responsibility that I wasn’t going to “burn the house down”. To their delight, I’m sure, it was never an issue.

Soldering came to me because I was a model train nut in my pre-teens. Running wires and switches for tracks, sidings, lights and so on with nothing more than electrical tape was, really, more of a hazard than my wood burning set.

This blog won’t teach you how to solder. Neither will too many of the online videos or “instruction” pages I’ve seen. You want to learn to solder, find someone who can do it well, beg or bribe them to teach you. One on one. Makerspaces are a fabulous resource for this.

The dead giveaway for someone who lacks soldering skills? They use the gun or iron as a “paint brush” to “flow” the solder around the connection. You don’t wipe a solder joint with an iron to flow the solder. Unless you’re sculpting.

Guns, Irons, Stations, Torches

When you’ve got soldering under control, and don’t expect instant miracles, you may want to actually buy some soldering gear of your own.

If you’re under the impression that you can buy a 25W soldering iron and you’re good to go, my best advice would be save your money. Go see a movie. Why? Because the pleasant experience of the movie will last a heck of a lot longer than a 25W soldering iron experience will.

So let’s start with the cheapest thing that will melt solder..and the thing to avoid buying if you can…

Wellar

First, Weller makes some truly great products. A pencil styled soldering iron isn’t one of them. Think of these more as a fabulous wood burning tool and you won’t go wrong. True, they will solder, in some cases, but as you get better with soldering, you’ll toss this thing. Main drawback? No temperature control adjustment.

Next up we have soldering guns. Like this one:

Weller 8200n

Runs 100 to 140 watts, easy tip to replace. You can use it for almost any gauge of wires from 14 to 26. You won’t use it to solder any components on a printed circuit board. The tip is too large. If you’re building a 3D printer, the one place you need this gun?

IMG 1218

That’s right. When you soldering the wires on to the bed heater. The bed heater is a big chunk of aluminum with a copper pattern on it. The metal dissipates the heat so fast from a soldering iron, only a gun will work. Plus the gun has to match the area. That’s a 220mm plate with a 100/140 watt gun. If you have a large metal plate, like 300mm, you need a 220/260 watt gun.

These old Weller guns last, well, at this point…here’s a snap of me at 15 when I was fixing my guitar amp (yeah on the kitchen table)…that is the SAME gun in the heated bed photo above. It is 50 years old and it still works just fine and the only repair was I put a new plug on the end of the power cord.

Mel Soldering

Plus in a pinch when I didn’t have a replacement tip (they do wear out), I’ve grabbed a piece of house wiring, 14/2 (NMD7), stripped the insulation off it, bent it in the shape of the original tip and it works, just fine until I can get a replacement tip. Which they still make…

As to why I am fixing my amp, I couldn’t afford to take it to a tech so I learned enough electronics that I could do my own repairs.

On the list next are soldering stations. To me, even a lousy one of these is better than a pencil iron.

Stations vary in quality. A lot. Typically a Hakko (genuine) is the cream of the crop, everything else is a wannabe. However, if you don’t do a lot of soldering, you don’t need a top of line station either. Again, match what you want to do with the gear to do it.

What you want in a station is first, replacement tips, with a chisel tip of 1.2mm or 1.4mm being the standard tip for component use. There are scads of tips to pick from if you have special requirements. Order a few extra when you buy the station. If they stop making tips for your iron, the iron is a conversation piece.

Second, you want temperature control. And not some analog gauge that looks like the black/green/red one from an old battery tester either. A digital read out one that has a knob to control not push buttons.

Below is an example of a relatively inexpensive station that will do a decent enough job and not put you in the poor house. Notice the place that holds the iron? It has both a sponge and a wire shavings area to keep the tip of the iron nice and clean. Oh, and don’t forget to wet the sponge before you use it. It’ll last a lot longer…:-)

Station

Last on the list is a torch. And again it depends what you’re doing. Like plumbing. Torches are great! Working on a printed circuit? Not so great. Pay attention to what the pros use, get something along that line.

Solder

Of course, having the melting tool isn’t going to do anything unless we have something to melt. In this case, solder.

And all solder is created equally right? Nope. You need to match the solder to what you want to use it for. Unless it’s an emergency or some stop gap measure in which case, yeah, we’ll use whatever we can lay our hands on.

Lets start with the big stuff…as in plumbing…typically 60/40 or 50/50 (lead to tin mix). You’ll need some solder paste, clean joints and a spool of this stuff:

50 50

And a torch. This is big heavy stuff, takes a fair bit of heat to melt it.

Moving on, we get to electronic stuff. Printed circuit boards, wiring, finer detail stuff. And in a pinch, automotive as well.

Solder Type

Here things get a little complicated because there are two very different types of solder in use. One is the age old lead/tin and the other is lead free. There are pros and cons for both so pick a camp on your own choice. One thing to keep in mind is that if you’re repairing something that was made with lead free solder, you need to use the same.

Solder Diameter

Soldering diameter is also important. You want something with a .31 or .32mm diameter if you’re doing PCB work (or general smaller gauge wiring). Buying by the pound, Kester for example, is usually the best way to buy. But it’s not cheap and if you have to mail order it, keep in mind that it is a pound weight…

Quick Review

I recently got a tube of MG Chemicals solder, lead/tin, to try out. My normal brand is Kester 44 sn63/pb37 (tin/lead).

The first thing I asked myself is who in world decided to ship solder in a tube? So I thought about that for a minute and I think that they are saving on packaging. Normally solder comes on a plastic spool, inside a cardboard box. By shipping it in a tube, for a small quantity, they move away from that problem. Cost effective, don’t know about the plastic tube in landfill though…

Course the day I buy a small quantity of solder isn’t going to happen any time soon.. So the first thing I did:

IMG 2360

Yep, pull it out of the tube and coil it up. And I have to say it does make a nice sized coil. But it got me to thinking… MG sells solder wick, and I readily admit I have used wick about 3 times in fifty years), in a “spool”. I’d suggest the plastic tube would be better served with a simple spool like the wick. But I’m not a marketing guy so…just what I’d prefer.

IMG 2361

As I mentioned before, I’ve used Kester solder for a long, long, long, oh heck, since I started.

When using the MG, I found that it doesn’t flow as easily or nicely as the Kester does. And really, 63/37 solder is 63/37 solder. Thus the difference has to be in flux.

MG Chemicals says, “RA-like flux core” and “It generally exceeds J-STD-004 and J-STD-006 specifications

Kester says, “The high mobility and fast-spreading action of this flux results in more reliable production line soldering. 44 is classified as ROM1 per J-STD-004

Whatever all the heck that means. Me? I’m just an end user and I like the flux wetting action of the Kester by far.

While I really like the new MG Chemicals PLA, the solder? True is does do the job, but …meh.

23
Jan

Octoprint Webcam

One of the nice things about Octoprint is that it’s relatively easy to add a webcam so you can easily view your print progress from your local network, or from anywhere on the internet if you so choose.

What’s not so nice is trying to get a camera working sometimes.

I picked up a couple of Logitech C270 webcams when a local store put them on sale. Plugged them into the USB on the Rasp Pi 3 (the other went on a Rasp Pi 2), booted the PI and printer up. Working. No muss, no fuss.

And the first problem. I hadn’t thought about it but when sitting in front of a computer you’re about 30″ away from the monitor in most cases (arms length), so that’s the fixed focus point for the majority of webcams. On Thingiverse there are any number of focus ring hacks for the C270 cameras so you can actually adjust the focus as need be.

Therein exposing the second problem. Depth of field. Ever notice those telephoto shots in National Geographic are sharp on the subject but the background is typically out of focus?. Webcams suffer the same thing. If you focus on the center of your printer bed, when the head moves to the edges of the bed, they can go out of focus.

Once you get the focus adjusted to where you want it, the camera in a nice convenient position, I’ve found that the field of view is very narrow. In other words, you see about a 4″ square in the center of the bed. Outside of that is beyond the cameras view.

For a webcam to work nicely, it should be a wide angle lens, and adjustable focus.

First Webcam Test

I scoured fleaBay for some of the cheapest webcams I could find and ordered some. As in $3 webcam. No doubt the ultimate quality. Or not. For the price, if it didn’t work, who cares.

The first one I tried was described as: 8 Mega Pixels 50M 6 LED USB Webcam Camera. Whatever the heck all those numbers meant. Essentially 640 x 480 with a manual focus ring. USB 2.0.

When I plugged it in, no soap. Where the image should have shown in Octoprint there was a place marker.

8 Mega Pixels 50M 6 LED USB Webcam Camera with Mic for PC Laptop Computer | eBay 2017 01 23 12 44 58

Octoprint really doesn’t do the webcam any way, there is a jpeg Streamer it links to on the Raspberry. Obviously something was off.

A quick Google and I found the Octoprint Webcam Compatibility List.

Reading down through the list I found this reference:

Webcams known to work  foosel OctoPrint Wiki  GitHub 2017 01 23 12 50 07

I didn’t bother checking the USBid of the camera, just looked at the configuration needed to make the camera work and what file to modify. This info is right at the top of the webpage as boot/octopi.txt

Going to have to SSH to make the change. So off to another computer on the network to run a terminal program. Mac guys can use the Terminal app in /Applications/Utilties. Windows users seem to prefer using PuTTY. Since I’m not a Windows user, I can’t help with PuTTY but most term programs work the same any way so my screen shots should look more or less like what you might see.

Raspberry Pi IP

You’ll need to know the IP address of your Octoprint installation. If you can’t figure it out, there’s actually a plug-in for Octoprint that’s quite useful. It’s called “Detailed Progress”.

Oct Detailed

To install it, click on Settings–>Plugin Manager–>Get More and look through the list of plugins you can download.

After the plugin is installed, the Pi will reboot and when it starts back up your LCD display will show the IP it has on your network. That’s the IP you’ll use in the Terminal program to SSH to it.

The plug in will also display, during a print, the elapsed time, the time that the print will finish, the estimated elapsed time of the print, and percentage done.

SSHing We Go

Run your Terminal application and you should get a prompt where you can type in commands…and you type in the following line replacing the IP with the IP of your Rasp Pi and press return:

SSH PI IP

On the Mac, you might see something like this if you have never SSH’d into it before:

SSH PI Authen

What it’s saying is it doesn’t have a ECDSA, encrypted digital signature for the host, so…type in yes, we want to make sure in future the Term program knows who this host is.

Next up you’ll be greeted with the Password prompt. No brainer, if you’ve never changed your Pi’s password, it will be raspberry

If you’ve used a different password, use it. A successful login looks like:

SSH PI LOGIN

When you arrive on the Pi, you’re in your users directory so use this line to give yourself admin status and go into the text editor on the Pi:

sudo nano /boot/octopi.txt

This is a text editor, you don’t use the mouse. You use CTRL keys and your keyboard arrow keys to move around.

SSH Nano 1

Use the arrow keys to move the cursor down to just below where it says, “# for available options”. The # symbol means the line is a comment, not a command.

Press Enter to start a new blank line and type in the configuration for your webcam. In my case the line will read:

camera_usb_options=”-r VGA -y” and end the line with the return key.

Press CTRL O, this will write out the file and yes, you want to overwrite the old file.

Press CTRL X, to exit the Nano text editor

Back in the terminal now, type in:

sudo reboot

You can now quit your Terminal application.

The Rasp Pi will drop the connection to your computer, reboot and you should then be able to pull up Octoprint and have your web cam work.

19
Jan

3D Printing Power Meter

Just wandering through fleaBay sometimes produces a “hey that looks kind of interesting”…which then unlocks the labyrinth of bunny trails.

Since energy seems to be a topic, when I spotted a simplistic energy monitor, well, heck, let’s take it for a spin..

Energy Monitor

This is a 20 AMP AC monitor, a cumulative monitor no less. For the rock bottom cost of $10 CDN. For bucks like that, it’s probably so accurate it’s even used in medical applications. Or Not.

IMG 2295

A whopping four screw terminal is all you need to connect said wee beastie to the AC source. Which in my case (in the event you are not in North America) 120VAC.

IMG 2297

The unit brags that polarity is not an issue, none the less I tried to keep the neutral and hot leads where they might go logically. This is using the broad assumption that the engineer who designed this anticipated such logical thinking. Or Not.

Instead of leaving those uber friendly 120VAC lines laying around, I made a quick box and printed it to house the hazards.

IMG 2301

Next, up, what to measure?

3D Printer

This was solved fairly quickly since I had a 16 minute print job to do. I plugged in the Energy Meter, turned on the printer. Darn thing worked. Am I surprised? Yes, I am. Many is the time I have received things from fleaBay only to have the smoke leak out on the first power up.

From the first power up, with no printer even turned on I got this information:

PM Start

Next I turned on the printer. In my case it’s a Kossel 360W 12Vdc 30A power supply, Raspberry PI Octoprint AC adapter). I initiated the print and the bed starting heating. According to the Energy Meter, it’s using 10.3W of power, 140ma. Not exactly a power sucker.

I examined the 12V power supply to see what the current draw was when connected to the AC line. Yeah, what was I thinking. I dunno. Line voltage is the only spec for AC they give you.

PM Bed Heating

Once the bed was up to temp, the hot end kicked in. Oddly I thought the bed would be the demanding one. Turns out the hot end is actually the energy sponge. At this point the bed is not on. Just the hot end.

PM Printing

And then the bed kicked in, with the hot end. With both heaters on, we have a 2A load. Not exactly a heavy power user. To put it perspective, five of these printers would use less than an electric kettle, although it will run longer…

PM Bed Printing

After the print job was completed, the energy meter displayed the Wh (watt hours) used for the 16 minutes. Of course the printer was still on and drawing power so that is displayed as well.

PM Complete

Summary

So what’s the point of all this? Honestly it was more curiosity than anything else.

I can’t see this saving any money or anything, and considering the energy meter itself is a load, if left on for long enough it would add itself to the energy cost.

Plus it’s not like companies who build/clone 3D printers are going to suddenly get energy responsible any time soon. You can’t compare energy costs of this printer vs that printer, magazines don’t even give out that sort of info in their reviews.

I’ve never a review that stated, “While this printer turns out incredible print jobs, the energy cost is far above/below normal”. Wait. I’ve never seen the latter, I’ve seen the former too many times without any supplied hi-res photos of actual print output.

So there you go, for what it’s worth. Which could be slightly less than some of the reviews you’ve read. Or not.

13
Dec

Octoprint – Webcams – Slic3r

Not a day goes by that I don’t learn something new about 3D printing. Sometimes it’s fairly important, other times it’s more of a “Hey, how’d I miss that one?”

This entry is more of the latter.

For the past several months I have been throughly putting both Astroprint and Octoprint through their paces. Originally Astroprint was winning and that’s kind of odd when you stop and consider that Astropint is really a fork (subset of code) of Octoprint.

Astroprint simplicity for setup and usage, plus it’s fairly limited capabilities were the advantages. However the Octoprint crowd hasn’t been sitting by either and with the last two or three updates, I’ve completely swung over to that side of the platform. So who would want to use Astroprint? Someone who wants the absolutely easiest setup and an interface that actively scales astoundingly well to any device you connect with. Cellphone, tablet, computer, all look and work exactly the same.

What you give up with Astroprint is control during a print job. Therein lies the major difference. Octoprint is like running Repetier Host but remotely.

For the reminder I’ll stick with Octoprint. Note, this isn’t meant to be a guide on getting Octoprint running, there’s plenty of info on the net for that.

Webcams

Octoprint allows you to connect almost any USB webcam to the Raspberry PI it runs on. Webcams vary, in quality, price, mounts, well, just about every aspect you can think of. Octoprint has a web page that shows webcam compatibility so if you’re not sure, check it.

The benefit of having a webcam is not that you can watch your print in progress, it’s that you can CHECK your print in progress. Normally when you log into Octoprint you can see a progress bar. This more or less tells you the printer is still running. Not what it’s actually doing.

Hence if something has went wrong during the print, you’ll be able to see it immediately. A side benefit to this that you can even do a time lapse photo session of the print. Not to watch your print in fast motion but more to say critique the progress and spot any weak areas. Least that’s what I do with it.

As it happens, Staples had a sale on the Logitech C270 web cams so I took advantage of it and picked up a couple. These are HD web cams, 1280 x 720 wide screen support. Small too…

C270 Webcam

To make them work, I plugged them into my Rasp PI’s running Octoprint. Done.

Webcam Gotcha

After plugging in the webcam, a few things become abundantly clear. The first is if you are thinking about mounting the camera to your printer, keep in mind any vibration from the printer is not going to help it.

Second, these are WEB CAMS. Think about how close to you those web cams will be and you’ll get the feel for the minimum focus distance. Some web cams have adjustable focus, the C270 does not. I found anything closer than 30cm was starting to get blurry.

Lastly, once you have found a place for the webcam at a decent focus distance, you still have to mount it. Seriously these things have lousy mount options.

So let’s assume you need the camera close to the build surface. You need to modify the camera for manual focus. Fortunately Thingiverse has some items you can print to assist you with this. Like a complete new camera front with manual focus.

For mounting, a quick search of Thingiverse will reveal all kinds of mounts. I chose this mount and modified it for my own setup.

IMG 2053

Yep, some PLA, 3M screws and nuts, chunk of 2×4. True maker style. Sits nicely between the two printers I have.

IMG 2055

Running my web browser and pulling up Octoprint, this is what I see from the webcam on Bullwinkle:

Bullwinkle WebCam

I did have to remove one bank of LED lights I had on the build platform because they washed out the camera too badly. But I still got to leave one connected. It helps.

One other advantage of keeping the camera further back from the build area is you can see the full height (200mm).

Slic3r Coolness

Slic3r options:

Send Gcode OLD

So normally what I do for slicing is, run Slic3r, open the STL, change any settings I want, slice the STL, save it to my drive, quit Slic3r, run the web browser, connect to the printer, locate the GCODE file, and either drop it on the browser window to upload it, OR use the “upload” button in the browser to send the GCODE file to the printer.

So imagine my surprise when I spotted a couple of screen shots from other Slic3r users…mmmmm and then the Octoprint posting news…

Send GOCDE

What manner of silicon snake oil do we have here…turns out it’s the healthy kind!

First off, get Octoprint running. Then run Slic3r on whatever desktop computer you normally use it with. Click on the “Printer” tab and you’ll see this:

Slic3r Octoprint

See the heading “Octoprint Upload”…click on the BROWSE button and Slic3r will look for your printer, pop up a dialog with what it found to allow you to select that printer (handy if you have more than one on the network).

Slic3r Find

If you click the TEST button, it’s not going to work. Nope. There’s a blank field under the IP address you need to fill in. To do that, point your browser to Octoprint and select “Settings”–>”API”. See that BIG LONG line of hex in the API key? Copy it.

Octoprint API

Switch back to Slic3r and PASTE that API key under the IP address. SAVE the printer configuration and that’s it.

From now on, when you slice, click the SEND to Octoprint button and the GCODE will be stored on the microSD card for you. It won’t clutter up your hard drive any more. If you have more than one printer, as I do, just select that printer profile in Slic3r and that’s where the GCODE will go.

Since I’ve started to slice this way I’ve found it super handy. Oh, if you open multiple STL’s in slicer and you’re wondering what the file will be saved as, it’s almost always the name of the first STL you opened so that’s what you look for on Octoprint.

7
Dec

Printer Vibration Iso – Part 2 et al

Before I get into the meat of the topic, I’ve noticed something rather interesting with the Arduino IDE and the Marlin firmware, at least on a delta printer.

During my tests with the firmware I’ve found the RepRap Smart Controller (an LCD2004) is very unresponsive when I was using the button on the controller. The whole printer “worked” fine, but, it was obvious that something had changed.

I initially thought that one of my “mods” in the firmware had affected it. However after going over my notes I couldn’t find anything that should affect the response of the rotary knob.

Purely by accident I was making yet another change to the firmware, when, much to my surprise, the rotary knob was back to fully responsiveness again. Say what?

I had inadvertently run the 1.6.5 version of the IDE and compiled and uploaded the firmware. Ah ha! I quickly ran the 1.16.13 version, re-flashed the firmware, ah yes, dodgy again.

Couple more tests and I found any Arduino IDE after version 1.6.8 caused the rotary to be flaky. I have no idea why, if it’s something in the IDE that has changed, if one of my libraries isn’t happy, or what, but it warranted a post-it note on the printer to remind me…

Printer Vibration – correction…

After my initial tests with my db meter a few days back, there’s been something gnawing at the back of my brain. Trying disparately to get out. Apparently. See, the 82db just didn’t ruddy sound, skip the pun, right. In my recording studio I’m well versed with sound check levels and something was wrong.

Tonight the penny dropped. I was metering the printer again with some new feet I made and I was sitting at 54db. What? How the? And then, as I said, the penny dropped. So for you audio geeks, here’s the scoop.

When I measured the original sound level previously, I was standing 1 meter in front of the printer. Cause sound measurement levels are supposed to be 1 metre away from the source. Tonight I was standing about 45 degrees off the front, but still one metre away. After scratching my head for a second or two…bingo. It hit me.

Or rather it didn’t “hit” me. What didn’t? The air stream from the fan. On my printers the fan blows directly towards the front of the printer. All db meters have very sensitive microphones and what I was measuring was the air pressure from the fan that blows 8CFM. If I put my hand in front to block the air flow, of course the sound level dropped.

But from the side, yeah, no air stream. Room was 50db without the printer doing any print job, and 54db with printing.

Live and learn. Again.

Feet Version 1

Here’s a recap of the original concept feet. I threaded the center of the vertical 2020 beam with a 5mm tap, screwed the mount to the corners, added the cute dollar store balls.

IMG 1987

Within a couple of days I found a couple reasons why this wasn’t a terribly bright idea. The first is, the damn balls roll. When I whack the stuck off the print bed, the whole printer wants to move because the print is stuck there. I also found the when printing with any speed, there’s a lot of movement going on. No, not so much it’s going to roll off, but enough that I didn’t get any warm fuzzies.

Lastly, there was the quality of the balls themselves. We’re talking dollar store stuff. I had visions of one of the balls splitting in half and the printer looking like the leaning tower of Pisa. Or worse, on my floor. In pieces.

This, of course, lead to a rethink.

Feet Version 2

It sort of started with, gee, I wonder what the balls are made of. Out came the box knife and I halved one. High density foam rubber. And not a lot of air holes in it either.

As I stared at the half, there was a spark of, ingenuity? Okay, so I didn’t want to throw out the pieces..I designed a holder for them.

IMG 2010

I used the same 5mm screw location from the last test set, added some double sided tape in the holder and mounted one on the corner.

Feet Mount

True it does stick out somewhat but the center is directly under the corner and the print is using a 50% infill.

Foot In Action

Now if the ball splits or whatever, the most the printer will lean is about 15 degrees. Plus with the design the printer doesn’t roll around or shift it’s weight on faster print jobs.

Just for the heck of it, I thought I would add three more cups for a total of six.

Iso V2

Safe to say that once you have the corners done, adding more doesn’t do much. Perhaps makes it a touch more stable but not by any margin that I could measure.

The other printer I have, I stayed with the corner design only.

Iso v1

Of course this printer has more weight pressing down on the corners than the one with six support points but really, I don’t see any difference in the amount of noise being transferred into the cabinet below.

All I hear now is stepper motor noise.

Isolation Enclosure

One of the disturbing things I see is 3D printer owners building all manner of cabinet enclosures to assist in printing the tricky ABS, or trying to keep the noise from the steppers at a level where they can get some sleep at night.

Why is this disturbing? Pretty simple. Electronic components are designed to work within a specific temperature range. The majority of commercial components are designed to work from -30 – +70C.

The ATMega2560 CPU is designed to work -55 to +85C. With a heated bed, in an enclosure, warmed up to 80C+, the not so earth shattering news is the component is not going to last as long as if it was in the free air.

On the printers that are designed to be enclosed, there’s no doubt a cooling fan for the electronics and a vent out of the enclosure. However, these are brand name printers, not the knock off junk one finds on fleaBay, BangGone, or AliExpleatedDeleted…

Secondly, the RAMPS board has some MOSFET’s on it and while those handle heat quite well (depending on the MOSFET on the board), adding some 90-110C heat to it, you know, just to keep it warm, isn’t going bode well over time either. Plus if you have under gauge wire for the bed, a bad connection to the terminal block on the RAMPS board, yeah, not going to bode well. At all.

Food for thought any way.

6
Dec

Raspberry PI Monitor Mount

I’ve been using a couple of Raspberry PI’s for Astroprint (Astrobox) and Octoprint (Octopi) for the last few months and both of them have been performing perfectly. Although, what I have noticed is that running two Octoprints on two Rasp Pi’s Wifi connections take a little longer to establish.

Whereas with Astroprint, easier to setup, easier and faster to connect to. Resizes well to fit smaller screens like iPads or mobile phones. The gotcha is you give up a fair bit of control (like speed, flow rate, etc). Thus, pros and cons.

But I digress so…I have a couple of Rasp Pi’s that I use for various purposes and they work well. Except for a few things. Like being small, compact, easy to access and so on. While the Rasp Pi is billed as a true $35 computer, in fact it’s probably closer to a $250 computer. Add a keyboard, mouse and monitor, power adapter (a good one), Wifi dongle if you use a Pi 2 and it doesn’t exactly look like so good of a deal.

If you have spare components laying around, of course it does get more cost effective, but it’s still going to cost as much as a budget laptop in the end. Something to keep in mind.

What I loathe is setting it up, plugging it in to a monitor, keyboard, rat, because I want to do something in the GUI (Pixel) not the command line. Then tear it down and put it away. Ugh,

I have an ancient Samsung monitor, VGA, and that’s not going to plug into any Rasp 2 or 3 easily. So off I go to find an VGA to HDMI adapter…Amazon has them so I order one and it shows up.

Adapter

The adapter works but I do wish there was side nuts on that VGA portion so I could screw in the VGA cable from the monitor. Good thing it holds fairly well…

Unfortunately now I have this unruly 6′ VGA cable, power adapter cable for the PI and so on… It’s still not neat…

The back of the monitor doesn’t have any place to mount a Rasp Pi, there is no room on the swivel base that allows easy access to the microSD slot, HDMI and USB ports…so…

IMG 2023

I found a VESA mount for the Raspberry on Thingiverse…and printed it out. Then I looked at the back of the monitor and thought, what about if I designed a hanger…

IMG 2022

The expression is quick and dirty. I used a protractor to measure the angle off the back of the monitor the PI would need to be mounted at to make it vertical. Designed a simple hanger, screwed in the PI, added some stand off feet…and then zap strapped the VGA cable to the monitor stand.

IMG 2026

No cables running on the desk, all behind at the back of the monitor. When I need access into the PI to remove the flash card or get to the ports, it’s exposed and easy. I can use bluetooth or 2.4Ghz dongles for keyboard/rat and less cables.

Before I had a 3D printer, there would have no doubt been some project box, double sided foam tape, and an appreciable amount of misery involved when it comes to stuff like this. This is one of the aspects that really draws me into 3D printing. Making needed stuff…

27
Nov

Printer Vibration Isolation

Honestly I have no idea how I get started on these projects somedays. I suspect it’s like a an idea or concept that’s been trapped in the dark cobwebbed corners of my mind and suddenly, they burst to the forefront. Or something like that.

As a guy with not just one printer, but two, Kossels, when both of them get going, the radio in the shop, which isn’t exactly top quality in its own realm, loses out to them.

It’s been a sort of quest to find a way to get them to be a little quieter. A few months back I had a Turnigy on loan and it actually made my Kossels sound quiet. But it’s gone now and I hear the drone of my own printers.

Today I’d had enough and it was time to do something.

In the past I’d try any number of things and in the process I’d learn a few things. The first thing is if you put a printer on top of a cabinet or table, whatever is under it will instantly be transposed into a speaker. Depending on the frequency where everything meshes, and trust me there will be some resonant frequency, it’ll be a mid-range drone, or a sub-woofer growl.

My printers sit on top of a 6ft x 30″ by 42″H cabinet as shown. The shelves aren’t empty and this is a good thing.

IMG 1985

I also tested a printer sitting on top of a wooden table, one that is 2″ solid oak top, 2 1/2″ square legs and solidly built. The drone coming from under the table area was wicked and the legs transmitted the vibration downstairs to the main floor through the floor/ceiling. Yep, easy to tell when the printer was finished its print job if you were downstairs.

I picked up some hardwood floor sliders, rubber on one side, fuzzy backing on the floor side.

Floor Things

They work fairly well, certainly better than setting the printer frame directly on top of a cabinet or table top.

Still I wondered if more couldn’t be done. I set about sleuthing and found all manner of things. From a MagLev setup, that apparently would wander on its own if you didn’t have all the legs absolutely level. Which made sense, sort of like mercury finding the lowest point.

To printed spring feet and even springs inside of holders. They were billed as vibration dampers but really, they just cut down the vibration from transmitting to whatever the printer was sitting on. If the printer shook to start with, it shook when all was said and done.

In a lot of ways, it reminded me of my recording studio. Where the monitors tend to reflect down into the shelf or cabinet they perch on top of. If it was concrete, no vibration at all. But that’s kind of heavy and unruly to deal with…

Just for a test, I lifted one of the printers while it was printing to see what isolating it might sound like. Wow. From the usual drone to little stepper motor noises.

I put it back down on my cabinet and grabbed my DB meter.

IMG 1986

The lowest reading I could get was 83db @ 1 metre. Moving the meter around I could get 85+db though.

I was thinking about mounting the printer on rubber pneumatic bladders like we used to have at work when I happened across a Thingiverse item. A very simple design, used dollar store balls about the size of a golf ball. I modified the mounts slightly and built my own.

IMG 1989

Those are somewhat soft squishy balls, worth all of $1.25. And wowzers, do they work.

All I hear now is the steppers. No more drone coming from the printer/cabinet/table. Because the balls are bouncy, I found the whole printer does move a little more, so I don’t know at this point if that’s a good or bad point.

It could be a good thing since it’s absorbing some of the energy of the printer as it tosses the hot end around. Most deltas tend to have vertical energy as opposed to the Cartesian’s X/Y axis energy.

Out with the DB meter again, doesn’t matter where I measured from at 1 metre, the highest I can get it is 81db. As far as sound goes, 2 or more db is a significant change. A 3db change is often perceived by the ear as twice the volume, because the ear is logarithmic not linear.

There is enough weight on the balls that there is no way it’ll “roll” off, perhaps even different kinds of balls would perform differently as well. No idea at this point. If these “high ticket” items start to sag, well, another $1.25 and all would be well again…

I also saw someone use tennis balls in the same concept. I also have those but the little toy balls seem to work just great so that’s what I am going to test with for the meantime.

So there you go. What to know what your printer would sound like if you did the same thing? Lift it up whilst it’s printing. If you like that, print the mounts and isolate it.

Trendy….

17
Nov

Delta 3D Printers – Mirth, Myths and Madness

3D printing is not new, it’s been around in some form or other since 1989 or so. What is new is the introduction of 3D printing for the hobbyist, we poor unsuspecting souls. This has been gaining momentum since 2011.

A quick search of the net will result in the fact that there are over 1,000 different 3D printers available today and a small percentage of those will be delta style printers. That small percentage is the basis for this blog entry. Dated, today. Stardate whatever…to go where no man has gone…oh wait, we have gone there.

Delta’s owe their heritage to Johann the person who provided the jumping off point, not to be taken literally, for the delta’s we have today. His first prototype was the Rostock, followed by the more refined Kossel.

While it seems like age ago now, a mere short 18 months ago what I knew about 3D printing could be written on your fingernail, in large type and the nail would still be plainly visible. I suffered from D.A.A.P at the time. What’s DAAP? Dumb As A Post. To put it into perspective.

When I started I understood there was some hardware and software to make the thing work. Software I assumed would be fairly easy because I’ve been writing software since 1979. That was a bit of a mistake looking back, but at least I had the background to figure things out.

The hardware, that looked amazingly easy, turned out to be not quite as straight forward as I assumed. Thus I decided I’d better have a good backup plan before I “built” any type of printer.

As it happened, David, one of the members of Fraser Valley Makerspace had cobbled together some extrusion, electronic bits and mechanical pieces, and made them available through the Makerspace as a Kossel kit. He had a working one, so…I decided it must work and bought one.

The Madness

There are seemingly two kids of people who want 3D printers.

The first are those who want to use it like a toaster. Take it home, plug it in, briefly read enough of whatever documentation there is to make toast and use it. Of course there’ll be some burnt bread, but there’s a better chance of it working at the on set, the learning curve will be mainly filaments and software.

My first piece of advice, if you’re this first type, buy a Cartesian printer. Brand name. Make friends with other people who have them, even better if they are local to you. Check out any local maker spaces, they make great resources. Something eventually will not make sense and/or break, you need a backup plan to keep the toaster toasting.

If you must build a kit, find someone who has built one that can help you build it. As a friend of mine put it, two heads are better than none.

The second types are the tinkerers. My ilk. Folks who love to build stuff, take it apart, tweak it, make it work better, change it, redesign it, use it and educate themselves to no end on it. Whatever it might be. There is as much joy in building as there is using for me and my ilk.

My logic at the time was that if I got stuck at some point in the build, I needed a parachute to help me over the rough areas and that would be where the Makerspace came in.

I had zero clue at the time I’d be dangling off that rip cord for more than a month with the ground rushing up at Mach 3.

I owe my sanity in my initial build to one of the FVM members, Rob. While he’d hadn’t built one of the kits himself, he did own a Ditto 3D printer and had single handedly got the mini-Kossel working at the space. Thus when I got stuck or didn’t get something, Rob to the rescue. A lot. He become, unbeknownst to him, Rob Rip Cord.

Even with a well equipped workbench, micrometers, scopes, power supplies but I have to say that I found I needed a metric tap and die set, metric drill bits, metric hex wrenches, metric hex screw drivers. I did a lot of shopping on fleaBay.

Plus my kit didn’t include any preformed wiring harness, no Dupont ends already in place, no power supply, or power supply wiring, thus for a fair chunk, I was on my own. However, having built circuits since I was 13, it didn’t really present much of a challenge in many respects.

There was a manual that I downloaded. It was supposed to be a guide on how to build the Kossel. Pretty evident from the start that the downloaded manual was for a different printer. Everything from the nuts and bolts to the extrusions were different. Sort of like building a Chevy with a Honda manual.

While I thought this lack of instructions must be unique, in hind sight I have now found scads of printers in kit form that clearly state, “If you don’t know how to assemble one of these, don’t buy this because we offer no manual or limited technical support”. Of course the price of the kit reflects this but still…not what a first time builder wants to start with. Me? I suffered DAAP, I was undaunted.

I finally reached the frustration point where I was either going to toss it out, or find the humour in it. Fortunately I found the humour.

IMG 0119

And while I’d like to think that I know what I am doing when it comes to building things, yeah, not so much for a 3D printer. Mostly due to the fact I didn’t know how the thing worked in the first place. DAAP.

I did everything backwards, wrong, or just dumbly. Heavy on the dumb. Hey I even lost some of the ball bearings out of the linear rails because I didn’t know they just slid off the rail…oh yeah. A comedy of errors abounded.

Yet, I still remember the first print…and no, it’s not supposed to be a lace doily cube. It’s what you get when you don’t have the foggiest notion of what you’re doing but you do it any way.

At this point, I wasn’t believing in miracles, I was relying on them.

IMG 0188

So I churned out a few of these stringy things, and they might have made good scouring pads for pots and pans, but something was amiss and I didn’t know what it was.

The Myths

And of course like every desperate individual I turned to the internet for help.

I was still suffering from DAAP I should add.

Using the net without knowing much is like using Dr. Google as your personal physician. There are thousands of DAAP sufferers like myself whose opinion and help is about as useful as a milk bucket under a bull.

Thus it was finally through the Makerspace gurus that I learned something new. A thing called “bed levelling”. My prints didn’t adhere to anything because, well, my basic point of reference didn’t exist. At least in this world.

My Kossel kit had an auto level probe, but for the Marlin firmware version I had, it seemed like every time I levelled, just before the print started the firmware tossed all the bed info it just collected and proceeded to print yet another scouring pad. Handy. Not. Auto level working? Not.

After learning many tweaked the firmware to adjust for the bed level I decided against that avenue. My logic was that if anything happened to the firmware I’d be doing it again, i.e. bugs in the levelling routines or whatever, well, yeah.

I decided to do bed level via mechanical style.

When I inquired how anyone levelled their beds manually, I was greeted with tales of woe, daring do, silicon snake oil and just plain dumb luck. I had copious amounts of dumb, just seemed to lack the luck.

The tragedy was that you loosened the top end stops with the micro switches on them and moved them up or down less than a cats whisker and hoped you got it right. For all three towers. With a flat blade screw driver. 1/8″ thick. Like that old saw, “Measure it with a micrometer, mark a line with chalk, cut it with an axe.”

I looked at the problem, pulled out a drill bit and did my first mod, on the 7th day. The ‘x’ marked the spot, put in an M3 x 6 bolt, the head triggered the end stop switch.

IMG 0199

What used to take days of fiddling manually to get right, took all of 30 minutes, 3 minutes to set the scripts in Pronterface. The only firmware tweak required was if the center of the bed was concave or convex. You had to change one of the rod lengths and re-level. Again, do it a couple of times and you can do it in your sleep.

For the X/Y dimension size, print a cube, measure it, calculate how much too big or too small it is, change a number in the firmware, level the bed if needed, reprint, check. Having built a number of Kossels for others, worst case from power on was out .21mm, best case build was out .06mm. You need that kind of accuracy to print a.. ah… Pokemon. Or something.

Eventually the FVM kit would be upgraded to include the screw carriage adjusters and better belt grips. Huge progress.

However the myth still exists today that delta printers are next to impossible to level, or will take days to do. So you must have auto level.

The real truth is, if you understand (or take the time to understand) how to do it, you’ll find you can manually level the bed, exactly, once. And unless you change the hot end, diagonal rods, effector or something that will change a dimension in the build area, you don’t level it again. Period.

I printed over 900 hours on my first Kossel before I changed the nozzle and did a re-level. In 15 minutes. Big whoop.

The fact is all 3D printers come with their own little bag of issues. Be it the slicer, firmware or how you communicate with the printer. Pros and cons. Plan on doing a lot of research and look for actual A/B print examples not opinions in a forum.

Lastly it helps, especially if you build a kit, to be an information sponge. Obtaining little bits of info from others with the SAME kind of printer as you and then TESTING that bit of info to see how it fairs on your printer will enable you to produce better prints.

Even after logging over 2,000 hrs on my first printer, I am still learning and testing what I can do to turn out better quality work.

The Mirth

You’d think that just having a printer that works would be joy enough. Truly it is very satisfying, but I’m going to step back a moment here and think out loud as to WHY my Kossel kit was more than I’d even hoped for.

LongJaw

For the two FVM kits I built for myself, my thanks goes to the FVM’er, David who, either by shear good luck or design managed to cherry pick most of the best parts for a Kossel build.

The one shallow item in the kit was the full graphic display (12864). As a software programmer I know how CPU intensive just updating these displays can be. I think I had mine on the Kossel for about 3 days before I tossed it in the dumpster (along side the auto level probe setup) and replaced it with a Smart LCD 2004 controller.

The rest of the kit, stellar. Just stellar.

The first is the linear rails. These are premium items that will give hundreds if not thousands of printing hours. Nowadays you see what I call the cheapskate bearings like the Rostock used for the carriages. They are big, burly, have mass, and will not wear well over the long term.

Second is the carriage pieces that I had a hand in modifying. The current ones hold the belts so much better and have the adjustment screws.

Third is the massive stepper motors in the kit. These are 1.68A steppers, probably overkill to the nth degree compared to the whimpy ones I see now, but they run great and cool.

The 2020 open beam extrusions do a good job of keeping the frame rigid, even when when printing up to the 210mm height on mine.

Then the stepper drivers. Out went the old A4988’s and in came the DRV8825’s. The 8825’s can deliver more current and/or finer stepping if you need it. Nice to have that additional overhead.

Heat bed. Many printers still don’t offer or come with a heated bed. My Kossels have a 220mm heated bed, large enough to print everything I’ve needed so far.

Top drawer extruder. Three redesigns later, the current one is the best design I’ve seen and I’d select it over any of the metal ones I’ve seen.

So…thanks FVM, David and Rob, from Rocky and Bullwinkle (and me of course)…

Twins Printing

9
Nov

Black is BAACCKKK…MG Chemicals

In my ever expanding quest to try out new filaments, I’ve always found that if you want to see how any filament performs, at the worst, just try out a roll of anything they make. In black. Seriously.

I’ve read that black filament is the toughest to print because of the dyes go into the production. Or magic. Yeah, one of those for sure.

Regardless of which of my delta printers I use, black has always been a bit of a duck shoot when it comes to getting good quality. Any other colour, no issues. Thus, must be magic. Yep.

As I sat staring at the two brand new unopened black spools of filament on my workbench I was undecided which I should try first.

The first was PLA, the new “improved” brand from MG Chemicals.

IMG 1911

The second, PETG. Truthfully PETG is my compromise to avoid printing with ABS (which gives me royal headaches) but it is so darn stringy and unpredictable that I haven’t printed with it much. Some would call that being a smart coward.

IMG 1912

Of course, I used common sense and did one at a time. And pigs can fly. Forget the common sense thing… I loaded up one of my deltas with PLA and the other with PETG. On the PLA I had to print out some tank treads for a robot I’m building so, 15 treads at a time. In black.

The treads are from Thingiverse Caterpillar Tracks. Although labeled as a work in progress, I’m doing it any way. Although I’d really like to build a fairly large Wall-E…maybe in time.

IMG 1903

My settings, 0.3 layer height, 50C bed covered in Elmers glue stick, 208C for the first layer, 200C after that. I’ve made 60 treads so far and they have come out absolutely perfect. No strings, no separation, just way better than I expected.

On the other printer, I decided to make something to hold my SD cards and flash drives. With PETG no less. Again, merely a design I found on Thingiverse called Moby_Stick

IMG 1910

My settings, 0.3 layer height, 50C bed covered in Elmers glue stick, 224C for the first layer, 222C after that. Used Slic3r’s built in support for the whale tail. Not the default supports but “rectilinear grid”, which I have found out is far better than the default support patterns.

On the whale the supports literally fell off when I chipped it off the heated bed. You got that right, I had to use a metal spatula to get it off the bed.

I’ve never had any issues with adhesion with Elmers and a 50C heated bed. I’ve read many a horror story from others about getting PLA or PETG to stick to the bed, heated or otherwise. With every solution from 70-100C heated bed to hair spray on painters tape, to Kapton tape. Me? Borosilicate glass, heated bed, 50C, Elmer’s stick.

Perhaps with a delta because the bed doesn’t move the glue stick approach works fine. But I’ve done the same with the standard Cartesian printer I had here and it stuck just as well. Thus the problem must lie elsewhere.

After the prints, I measured the diameter of the filaments. In hindsight it should have been done first but, well, in my excitement I kind of missed doing it. None the less, both the PLA and PETG measured out 1.75 on my micrometer.

Last year I used a number of different MG Chemical PLA filaments, which I will call “old stock” now. While colours like their gold or white were superb, some of the others, not so much. But this year, things are not the same old.

MG Chemicals has changed their products on Amazon. The new stock has cardboard sides and is labeled “Improved”. They aren’t kidding. I’ve noticed a few complaints about the size of the center hub not fitting some spool holders. Since I use spool rollers, spool center is a non-issue.

No idea what kitchen they are using to create this new improved brand of filaments they are selling, but so far in my tests, I’ve found that I don’t need my go to brands any more. I can grab a roll of MG, thread it up, and I know exactly what it is going to come out like.

When I add in the fact that MG is less expensive than what I usually buy, well, that’s just icing on my cake, sprinkles on my donut, gravy on my fries, well, you get the idea….:-)

21
Oct

Thermochromic PLA – MG Chemicals

Thermochromic filament is filament that changes its colour according to ambient temperature. I’ve mostly seen ABS filaments that change colour with even the slightest heat from your hand.

Thus it was with much anticipation at the outcome when I found myself with a spool of Mg Chemicals latest offering of Thermochromic RED PLA. Yep, PLA.

Staying in line with the rest of MG’s new products offering, it’s delivered in a zip lock bag, cardboard sides, and large spool center hub. All pluses in my book.

IMG 1839

I don’t know about the rest of the printing world, but it seems to me that RED filament must be next to impossible to make. Without fail, every red I have seen looks more orange to me than red. In my case, if it’s not fire engine red, it’s not red. So I of course, immediately looked at what MG ascertained was red.

IMG 1840

If you’re mumbling to yourself, that’s NOT red, well, you’d still be correct. Still, let’s look at the spool without a flash from the camera adding or subtracting anything from the colour. And for giggles, I’ll put a spool of eSun RED beside it.

This is MG Thermochromic on the LEFT and eSUN red on the right. MG’s is more in the purple hue range, and eSun is more to the orange. Still, if I have to pick something that at first glance is going to pass for red, it’s going to be the MG. No contest to my mind.

IMG 1843

Printing with the Thermochromic is no different than printing with any other PLA. I used the same temps, same retraction, same speeds. Wasn’t stringy or blobby in any way. Actually the more I use the new MG products, the more I like them. For the simple reason they are extremely consistent across the colour spectrum. I love not having surprises when I print…

One thing that catches you a little off guard though is when you look at the spool during the print job. It’s redish purple. And then you look at the print under the hot end. There’s a slight pink hue to it and other than that, it looks white.

IMG 1847

The beauty of thermochromic filament is of course that it changes colour. According to ambient temperature around it. One would assume that MG would have indicated the temperature range that will affect the colour. Which of course, at the time of this writing is the wrong assumption. There was nothing on the box, nothing on the filament label, no information that I could find that specified the temperature range. An oversight? Lack of data from the manufacturer? I honestly don’t know but it is something that should be addressed.

According to my own less than scientific tests, there’s about a 20F working range. Below is the finished print (Fossil Fish from Thingiverse) and the temp of the top of the print is 123F (50.5C the temp of my heated bed). You can see the tip of the tail fin has started to cool.

IMG 1849

Get down to 115F (46C) and you start to see more areas, again thinner areas cool faster…

IMG 1851

At 108F, 42C, things are starting to really change. Again, the thicker areas retain the heat better so you have to wait longer for them to cool.

IMG 1853

Finally at our human body temp, it’s completely gone through the colour change. This means that you can’t just pick up the print and have your hand affect the colour. If you’re looking for that temperature, MG’s thermochromic isn’t going to cut it for you.

Further, if you scan around the net looking for thermochromic filament specs to find the temperature range for the colour change, you’ll find what I did. Zip. I couldn’t find one company that actually spouted the specs for a PLA temp range for the colour change. All I could find was recommended melting temp. I found this odd, but seems to be the way it is. For whatever reason (plus I’m thinking the guys who dye the stuff have either never heard of Pantone or are colour blind).

Remember I said that this is more purple red? Heres the print from MG Red on the left, eSun red on the right. Natural lighting.

IMG 1855

If you’re like me you’d say the eSun is more red. But lets take the same fish and put them in front of a red toolbox lid.

IMG 1856

Isn’t perception a pain in the butt…so the key to the red/orange/purple thing is lighting, background, and frame of mind. There’s still no hands down colour winner but at least you know what to expect.

To summarize, I really like the new MG PLA. Thus, yet another winner for myself and MG.

The thermochromic is super useful where the temperature range will be hotter than the human body.

Where would that be? A few seconds to search Thingiverse for water tap nozzle should give you a few hints. Imagine you have kids and a PLA printed nozzle, if the nozzle is white the temperature is 115F to 120F+. Don’t touch it! Or jump in the shower unless you want to perform an equally quick jump back out.

Or make an ornament that hangs on the mirror in your car. When you come back to the car in the summer time, a quick glance will tell you if you want to open the door and jump in, or just take a step back as you open the door. Course if the ornament is on the floor mat, best to have someone else open the door, just to be on the safe side.

Something that sits on the mantle over the fireplace…in short, lots of places to use this higher range PLA. Just keep in mind the glass transition point…(60-65C).

Update: MG Chemicals informed me that the Red colour changes to natural at 43 °C / 109 °F. This is a little different than my somewhat unscientific approach with the IR temp gun readings. They stepped up to the plate with the info. Nice.

28
Sep

Wi Fi Fo FM

I’ve had a cheesy FM radio over the work bench in the shop for a considerable time now. A simple FM radio that can play a memory stick, runs off 5V, maybe 3 watts of audio power. Big maybe actually…

To use it you can smack a bunch of tactile buttons or an IR remote. When I can find it.

Wandering through eBay a while back I came across an FM radio, that looked a little better than my previous “cheese special” but what caught my eye was the “serial control” option for the radio. There is no card reader or USB port so it can’t play from a memory stick. But I rarely did that any way.

The radio itself isn’t much bigger than a standard sized business card. The usual jacks give you power in, speaker outs, a serial connection port and something labeled GRSV which I have no idea as to its purpose.

IMG 1759

There’s a blue LED backlight in the LCD display and the display is quite difficult to read at any angle other than straight on.

The eBay listing gave the basic serial port config (9600, 8, N, 1) and you send commands like AT+FREQ=1035 with no line endings to direct select a frequency. Which to my shock and surprise works quickly and seamlessly. There’s even a squelch setting in the radio so you can “omit” weak stations if you’re doing a seek up or down.

In reference to “seek”, the radio does not scan through the band and store the stations for you. That wasn’t why I wanted it any way. I normally just flip around between a few stations until I find something tolerable to listen to.

The FM radio works best when you power it from 3.3V, but it will take up to 5V. I found at 5V it got a little noisy at times, whereas at 3.3 it was better behaved.

I’ve found no way to have the backlight on all the time, in spite of others who outline a procedure to make it do so. But I don’t look at it much any way.

I had an old set of Apple speakers from an aged iMac. Put some Dupont connectors on the cables, shoved them into the FM board and they work really well.

IMG 1763

There’s no fancy EQ, if you can call what passes for EQ in these budget things an EQ any way. Sounds nice, that’s all I care.

The MOST annoying thing about the radio is fact that the knobs work backwards. Turning them clockwise decreases the volume or the frequency. I think who ever drew the PCB was either mounting the rotary decoders from the rear or with a jumper cable. So I modified mine to work like it is supposed to.

IMG 1760

Took all of 5 minutes. Works perfectly this way too.

For serial control, you can test things out with a USB to Serial adapter (keep the voltage at 3.3V) but I wanted Wifi control so I don’t have to go looking for a silly remote, I can turn off the radio from the network.

The simplest WiFi control I’ve used, over and over, is the ESP8266’s. Either as stations or access points. Great little work horses. And cheap as borscht… I used a Lolin version 3, with the cruddy CH340G on it for usb to serial and programmed it with the Arduino IDE.

IMG 1762

I didn’t use the RX/TX since that’s the USB serial connection. To keep the separate i used the Serial.swap() command. This moves the 8266 TX/RX to pins D8/D7 respectively. Ran those to the FM radio’s serial TX/RX and it works like a charm for control. In the sketch for the 8266, I hard coded in the FM stations I wanted.

Type in “radio.local” in any browser on the network and the radio shows up (it has MDNS or Zeroconfig as some call it). Pick what you want, away you go.

Radio FM Web UI

The buttons labeled Radio ON/OFF are not actually power ones. They are the MUTE controls for the radio.

The volume goes from 0 to a maximum of 15, and with a 3D printer running in the room, about 7 is good enough. With the printer off, 2 or 3 is ample for background music. According to what I read if you run the volume fairly loud, the two IC’s on the back for the amp tend to run hot so a heat sink for them is advised. At a setting of 7, they don’t even get warm.

Last, there is a place to solder in a wire for an antenna, and true for some stations just adding a few cm’s of wire helps reception. However for the most part the radio is quite sensitive any way.

One of the things I would have liked would be for the radio to have RDS (that’s where they broadcast the station name, and the song title; buried in the music broadcast itself). The radio IC in use has it, but the PIC chip that is controlling it obviously doesn’t support RDS. Which may not be a bad thing anyway since I’d have to put a full display on the radio so I could read it. Once in a great while…

A cool little one afternoon project that I’ll have to print a box for after I’ve tested it out for a while…

25
Sep

Sore Throat…On The E3D HotEnd

How’s that old saying goes, when it rains, it pours. Seems like just yesterday I was replacing a RAMPs board that went south. Oh, wait, it was yesterday…

Today, something else. As if. Like magic. As in print quality…more specifically, extrusion.

Last three days, I’ve been also having some prints that were under extruding. Of course after you crank up the tension on the extruder to the point that if it does burst under pressure the resulting shrapnel is going to be hard to dig out of the walls. And me.. So then you crank the heat to the point that the furnace in the home is no longer required. After which you blow torch out the hot end nozzle to get the printer working in case there was something causing an issue with the filament.

Murphy’s Law has already decided that you’ve missed the problem completely. Mainly because the part that is not working correctly is in the least accessible place. Inside the hot end. Of course.

Two things to keep in mind here, my printer has just under 2,000 hours on it (certain parts of it are original) and these prints I use for quick tests I print at a fairly fast speed. So I’m trading quality for speed.

This is what the prints had been looking like…bad one on the left, after the repair, good one on the right.

IMG 1753

Pretty easy to spot the one on the left that looks like there is an extrusion problem. And it’s true, there is. Just not where I was looking. As usual.

A closer look reveals how bad the ugly one was…now at a fast speed the infill doesn’t always drool up tight to the perimeters. I know that, so I don’t pay much attention to it. But for the large plain infill areas there shouldn’t be all those gaps. Houston, we have a problem.

IMG 1754

For the last year I’ve avoided taking the hot end apart other than to clean out a nozzle. I don’t know why. Probably because I didn’t want to re-level the printer to the bed. Which in reality takes me all of 10 minutes at the outside because I’ve done it so many times (not a fan of auto levelling delta printers).

Any way, when you rip apart the hot end, inside the cooling tower you find one of these:

Tube

The filament enters the metal tube and goes into a PTFE tube so it doesn’t melt in the cooling tower when you’re printing. Consider this a good thing.

I pulled the throat tube out of my E3D head and compared it to a replacement I have. You won’t have much trouble guessing which is the 2,000 hour tube (it’s the one on the left if you’re stuck)…

IMG 1757

Using a 1.5mm rod, I tried to push it through the tube and well lookie that, it was binding like crazy. Apparently the tubes do wear out but out of sight, out of mind.

On my replacement tube, the PTFE tube is a lot longer. Not sure if that’s a good or bad or indifferent thing.

Installed the new tube, adjusted the firmware for the new Z height, re-levelled the bed (10 minutes)… and printed the same Jack.

IMG 1755

The outline is closer, but not perfect cause the head is just flying around this small design (it’s a book marker), but the large infill is huge improvement.

Delta printers, because of their simple openness design, are at least easy to fix once you figure where the problem is. So add this little throat thing to your list of parts you’re going to need in the future.

24
Sep

Smokin’ RAMPS

My main Kossel printer has slightly less than 2,000 hours on it but the RAMPS 1.4 board on it gave off a very familiar odor the other day so I shut it down until I could get to it.

Later, I fired it up and it seemed okay. For about eight minutes. Then the room got sort of filled with smoke, accompanied by that familiar burnt electronics smell. No fire, but it did jam home a point that if I was 3D printing, I don’t want to leave the thing unattended.

Ripping the printer apart revealed the culprit. The heated bed MOSFET.

IMG 1748

Apparently it overheated, was laying against the terminal block and started to melt its way through, which then shorted out the terminals and…as they say, the smoke leaked out. End of life for short.

According to the specs for this particular MOSFET, it’s “supposed” to dissipate 110 watts at 25C. There is a heated bed about 2″ above it that is heated to 50C, which, probably isn’t helping it any either.

I thought I had a spare around here someplace, because, the simple fact is if you’re going to own a 3D printer, your best bet is to build one so you can also fix the thing when it will inevitably break. It’s not a question of will it break, but when will it break.

No way I could find a RAMPS board but David (FVMaker designer for this Kossel kit) had some spare boards. Life saver!

I replaced the RAMPS board and presto, up and flying. And of course, that’s more or less the same time I found the replacement RAMP board I’d ordered who knows when off eBay.

IMG 1751

This eBay special I found came with all the jumpers on and I thought I might as well set it up properly and once I’d done that I thought I’d also test it to make sure it was going to work.

Surprise. Surprise. It kind of worked but when I told the head to move, it only went half way. Ah ha. Stepper jumpers were not right. After rechecking about eleven_leventy times, they were set right. But I was still only getting half movements.

I started searching the net for schematics for RAMPS 1.1, 1.2, 1.3, 1.4 hoping to find what the heck was going on. No soap. I had a 1.4 board, no two ways about it.

Next step was pulling all the jumpers and testing with a digital multimeter. Imagine my surprise when I found it didn’t matter if the jumpers were on or off, there was continuity between the jumper pins regardless. Which, is, of course, wrong.

Pulled the plastic off the jumpers so I could see the circuit traces and wow. There is definitely some village that’s missing their idiot. See all the arrows? You can see the foil traces on the PCB.

RAMPS 14

Every set of jumpers for the steppers was done the same way. But why?

What I think was, no, not that it was a design error, but, for the A4988 stepper drivers, all jumpers had to be shorted to get to 1/16 steps. The PCB was designed with all shorted jumpers to save on the cost of adding those little jumpers, actually they didn’t even need to add in the pins.

However when the DRV8825’s came along, the jumper positions changed. But these boards were probably so plentiful they were sold as “proper” RAMPS 1.4 boards with all the jumpers.

Quick work with prying off the plastic holding the pins and a couple of minutes with an sharp blade and the board worked just like the other.

While I was comparing the two boards I had a look at the MOSFETs. The main original board used P55NF06 and the “repaired” board used IRF3205. According to the data sheets, the IRF3205 is the more capable MOSFET.

Under closer look at the data sheets you walk away with the idea that neither one of these is exactly what you’d call a performer. When the Vgs is less than 5V, there are better choices. Personally I’d suggest the IRLB3034pbf which would work well within the limits the 12V main supply to the RAMPs and voltages less than 5V for control.

To keep the MOSFET slightly cooler I added a small heatsink to my RAMPS. It’s not pretty by any stretch but it does help.

IMG 1752

Yes I know it’s mounted incorrectly (it’s not touching any other MOSFET even if it looks like it is in the photo), they didn’t design the PCB to have a heatsink so this worked out to be the best way. Unless you want to remove the heatsink and mount it somewhere off the board. Another option if you want to go that far.

The more closely I look at the RAMPS board I can see too many cost cutting short cuts on it. Thus, a good idea to have a spare….or two

10
Sep

Put a sock on it!

E3D would like you to put a sock on your hot end: E3D Sock No, really. I’m not kidding.

Silicone Sock Fillets

Seems there was this REDDIT thread where someone did this a while back and it’s been the single most requested item since that point. People have be clamouring for it. Not sure exactly what people but by reading the rest of the announcement you’d have a better understanding.

The socks come in bundles of three. Silicone, even high temp, custom poured, massaged by virgin ants, will eventually succumb to the high temp of the hot end (call it the Priestess end) and be sacrificed. Poof. Yep, you need more than one.

E3D is even including these socks with every new hot end they sell. You know, so you can keep your filament in your…I mean in check…safe PLA’ing and all that.

And really what 3D printer enthusiast doesn’t want a clean nozzle? Take a look at the photo of what your hot end looks like before and after being protected with a sock on it:

V6 with and without silicone

That’s right kids, if your hot end looks like the one on the left, you might want to have it checked. By a professional.

And SHARPER prints! The laws of heat transfer tell us that if your hot end is moving so slow above the printed object that it’s melting and distorting the layers as it goes, you’ve got more than a hot end problem. You got a SPEED problem. Big time and this little blue bandaid isn’t going to lower much of anything. Except your bank balance.

E3D even clearly shows how you install your sock to prevent dribble and just the tip of your hot end is visible.

Sock placement

Now perhaps Cartesian printers suffer from this hot end malady, but on my delta, with 1887 hrs on it, I barely have the beginnings of the disease… Whew, lucky huh?

IMG 1713

I do use tweezers when my hot end is getting up to temp and if there is any filament drool I whisk it away. Possibly that’s the reason mine doesn’t look like the one at E3D. Or maybe E3D was just going overboard for the shock factor.

Fascinating to see a market sort of created where there never was a market before. You know, because. Of. REDDIT. Where all the “experts” hang out (“ex” – the unknown quantity, “pert” – a drip under pressure). Like going to “Dr. Google” for medical advice.

Maybe I’m just old fashioned or not in the know, but apart from my tongue planted firmly in my cheek as I was penning this, I have no idea why a silicone sock for a hot end even exists. Maybe it’s the solution for those without some common sense. Like E3D. Who. Thinks. This. Has. A. Market.

[Addendum] It was pointed out that if you have fans blowing around the hot end, the sock can act as an insulator to maintain better control over the temperature of your nozzle. As opposed to wrapping your nozzle in insulation and Kapton tape (which is not nearly as inviting to lusty filaments). So perhaps in this case, a sock does make some modicum of sense. And I’ll leave it at that.

9
Sep

A PLA-sible day

3D printing tends to attempt to shorten the supply of printer filament on any given day. The keyword there is “attempts” for the simple reason there is so much filament available I seriously doubt we’re going to even make a dent in the current supply.

Having said that, it’s also worth noting that more and more manufacturers are appearing with offerings and promises of filaments that will take your prints to the next level. Having worked in the manufacturing industry for a long time, I have no doubt that a lot of the filament is simply a slight rebrand or remix of some existing filament.

So eSun, Hatchbox, AMZ3D, MG Chemicals, to name but a few, kind of boggles the mind as to which one to use. One would even think that PLA filaments are all basically the same. This would be incorrect, but a common assumption.

When I started with PLA, the two brands available were eSun and MG Chemicals PLA 1.75mm. Although both were PLA, they printed quite different in every aspect from flow to temperature. Depending on what I was printing more or less determined what PLA I used.

PLA Overview

While eSun hasn’t changed, MG Chemicals PLA certainly has. I’ve tested almost 3Kg of MG’s PLA thus far and it’s a marked improvement.

What used to come in a nondescript brown box, looking like something you buy in a back alley (hey, kid, over here, wanna buy some filament)…now comes in a colourful box that at least lets you know what it is.

IMG 1705

When you open up the box you’re greeted with a bunch of things I’ve never seen before…

First, the PLA is packed in a zip lock bag. You read that right. A zipped locked bag. You cut it open above the zip lock and you can pop the filament back inside and reseal it.

The second is the HUGE center spool hub.

The third is the sides of the spool are NOT plastic, it’s heavy cardboard.

IMG 1707

So let’s examine those items one at a time. First, the zip lock bag. The bag is vacuum sealed when you get it with the usual desiccate inside. What is not clear, nor could I find any mention on the box or a loose page inside the box, is, if you put the PLA back into the bag with the desiccate and zip lock it, does it remove any moisture or not?

Depending on that answer, if no, why the zip lock bag? If yes, MG should mention that because it’s a good thing!

So on to the hub. And my main gripe for a lot of PLA. PLA that is wound on a small hub is a pain when you got down to the last 1/3rd of the spool if you were using a bearing straddle spool roller. There is so much tension in the windings that the extruder would drag the filament off the roller. And on the floor, or wrap around the USB cable, or flopping about like a fish out of water.

Therefore the new larger hub is a WONDERFUL upgrade!

Last up we have the cardboard sides. Below on the right is a typical 1Kg spool of PLA (AMZ3D) and on the left is MG’s cardboard sided version, again a 1Kg spool. MG’s is obviously wider by a significant amount, but it is also significantly smaller in diameter. So it kind of depends if your spool has to fit in a specific area.

IMG 1710

Where I use my filament is in a spool roller off to the side of my delta printer. It’s obvious from the vacuum sealing process that the cardboard sides tend to suck in somewhat so I wondered what that might affect.

IMG 1721

As it turned out, it affects nothing. There is a slight tic you do hear once in a while where the cardboard is really pressed into the filament on the edges, but it’s not enough tension to drag the spool off the roller. So, 3Kg later, nothing to be concerned about.

Size wise, I used a micrometer and measured the filament diameter through out the prints, I found the filament was slightly oval, so a cross section would be 1.76 x 1.74 at worse case. I suffered no under extruding so it evens itself out.

First Print

The first roll of MG PLA I printed was green Glow In The Dark. When I opened the box I was shocked because it was already green. Wow, already glowing in the … ah…daylight? What? Apparently unlike any other glow stuff I’ve printed, MG decided to tint their PLA green to start with.

IMG 1708

Initially I though this was kind of dumb…and then, maybe not so dumb after all.

Most GITD (glow in the dark) filaments print some dismal shade of white/gray so in normal lighting they look about as exciting as a gravel pit. It’s only when the light dies that they start to glow.

MG’s on the other hand looks green to start with and in the absence of light, glows in the same green hue. Which means they look the same in light, or not. I’ve come to the conclusion this is a good thing.

That’s not the only difference either. The majority of GITD filaments I have used have a VERY textured surface on the RAW PLA. MG’s GITD RAW PLA is smooth as silk.

When both print, then the prints will exhibit the texture. Which I suspect is the globs of luminous stuff that makes it glow.

Of course, the big question, is, always, how long does it glow? Yeah, well, I found that MG’s glow permanence was no different than any of the others (eSun for example; but the eSun green not the blue). Matter of fact unless the room was pitch black, it was kind of hard to tell that MG’s had tapered off because of the green tint. The eye’s do funny things like that…

Two Pounds Later

Using a new filament is always a bit of a duck shoot when it comes to finding what temperature it likes to run at. Notice I said what it likes, not what we want. Big difference there.

MG’s old PLA liked heat. Although rated for 190 to 220C, I always got better results when I shoved that up to the mid-220’s. With the new filament, they changed the range from 190 to 230C. And really, about low 220’s is where the stuff really worked well for me (in a delta).

Raise the temp up high enough, you get “strings” as the print head moves around the job. Drop the temp by a few degrees and presto, strings disappear almost completely. I found the first layer was about 3 degrees hotter than the rest of the print.

The only drawback to heat, is that when you’re doing small areas and laying hot filament on top of hot filament and you don’t have any cooling on your printer, you’re like a piece of installed sheetrock/drywall. Screwed.

Keep in mind that this isn’t unique to MG, regardless of what filament you use, at whatever temp it wants, the saggy results will be exactly the same. In short, you need cooling if you’re going small and fast. Some try to go really really slow but at best it’s a loose bandaid to the problem.

MG PLA Summary

How many times have you read the “newer”, “better”, “faster” ads and walked away wondering what drug that ad agency was using?

With MG’s new offering, I have seen an upgrade that is a better all round product. One of the best is that if you used any of the old MG product the change to the new product is almost seamless. I’ve enjoyed how the first of the spool prints, to the last of the spool prints, it’s easily controllable, extremely predictable and overall I give it two nozzles up.

I’m looking forward to trying more of MG’s new PLA in different colours in the coming months. As I see it, a win for MG and a big win for me.

30
Jul

The Cycle of 3D Life – Thermistors

3D printing, undeniably, has to be one of the most fascinating, frustrating, researched, and misunderstood hobbies of all time. Not that I’ve actually had every hobby known to man to compare this to, but in the ones I have had, 3D printing runs at the top for the aforementioned.

Inevitably it starts with either a 3D printer kit, or a plug and pray…er I mean play printer. At some point, something breaks. Somehow. Quite mysterious in some respects. I’d blame the cat. Except we don’t own a cat.

Generally if you built the printer, fixing it is slightly more straight forward because you usually have a good source for parts and you know, more or less, how it goes together. On the other hand, if you have a ready to go printer, it can be somewhat tasking to find a shop that can or will fix it. Makerspaces are usually good sources for help or information in either event.

The two delta printers at the Wanch here, Rocky & Bullwinkle, have seen their fair share of repairs, mods, tweaks, adjustments and some mayhem that I throw in for good measure. Bullwinkle is the original printer, now 14 months old with 1800+ hours of printing time on it. Rocky is only 5 months and 170 hours.

Within the last couple of months, both printers have broken in the same way. Specifically the hot end thermistor. I suspect some collusion between the two of them for this to have happened but I can’t prove it. I’ll stick with, darn cat. You know, the one I don’t have.

You can find these little thermistors littered all over eBay and are very inexpensive. These are glass bead 100K styled and used to be stuffed inside a piece of brass tubing. There is a set screw on the hot end that tightened on the brass tubing to hold it in place. If you over tightened it, which took a fair bit of force, the glass bead shattered. Bad mojo.

A bigger issue was that companies would crimp the tubing on the end to stop the thermistor from sliding out. They got a little too carried away sometimes and the crimp would cut into the extremely fragile wires from the thermistor and cause a wire to break at that point. That’s what happened to both of mine.

Hot End Type1

At any rate, I suppose a lot of thermistors were getting broken because most of the replacements now are merely the glass bead and you reuse the tubing the thermistor came mounted in. I uncrimped the tubes so there’s some wiggle room.

None the less, now you’ll find a lot of thermistors that look like this:

Hot End Type 2

Or this:

Hot End Type 3

Much more friendly to mount and replace.

Ultimately on a delta because of the motion of the head, there is always some flex in the wiring and, yep, at some point, breakage.

Once I’d replaced the two thermistors, the first thing I noticed was that the heat cycles are different. Both printers seemed to struggle to maintain a nice even temperature. As in hoping all other the place, like +- 9c. That’s a big swing for the printers.

I have a window in the shop as well and if it was open, well, yeah, made things a lot worse.

Just for the heck of it I started looking for solutions and what do you know. Turns out all these thermistors that might look the same are hardly the same. Thus if you replace one, you’re supposed to tune for it. Who knew? I didn’t.

Low and behold, there is already a tuning routine built in the Marlin firmware (I’m using 1.02). Start with a COLD hot end, connect to your printer and send the following GCODE:

M303 E0 S200 C8

Your printer will start a self test cycle to determine the thermistor settings, S200 is the temperature it will use for the cycle. If you normally run your printer hotter or colder, use that for the temp setting.

Here’s a transcript of what the firmware does. Takes about 3 or 4 minutes to complete.

PID Rocky

At the end you get Kp, Ki, and Kd (not to be confused with Kraft Dinner) and you put those values into your Marlin firmware:

PID Configuration

After doing this with both printers, the temp control is FAR superior to what it was.

As an aside, I do notice that one one printer, the hot end temp will always overshoot by 5 or 6c during the initial heating but it settles back down to the correct temp nicely and stays there. Doing a little testing I find out that the heater itself is the culprit. Yeah, they aren’t all made the same either. Who would have guessed…:-)

12
Jul

3D Airprinting Vase Mode

In spite of the fact that I feel I’ve probably made more 3D printing errors than the average person, possibly due to testing to see “what THIS might do” or “cause”, there’s sometimes one of those “ah ha” moments. You know, where the planets align.

Tonight was one of those nights. I’ve printed a fair number of “vases”, single wall designs, to hold pens and stuff and I can usually spot the ones that will print out correctly, and the ones that won’t. But every now and then, one catches me off guard and this is the result.

IMG 1612

Yep. Typical Thingiverse design but it’s coming apart at the “seams”. Now I tried everything I could think of to “fix” some of these, and usually ended up with a big fat fail. Until tonight. Through pure accident.

I am testing out a Cartesian printer (Hobby King Fabrikator), kindly loaned to me by one of the FVMakers (David) and having some fun with it. I was printing some of my torture test prints on it and came to the conclusion that the way the printer is built is good. In this case the bed is the Z movement, the head does the X and Y. I like it.

This scooted me off to see what other Cart’s match this setup. Happened through PRUSA’s site. I started reading some of the blog and then noticed a title that said, “WHAT ARE PERIMETERS GOOD FOR?“. I almost didn’t read it and then I did. And BOY am I glad I did.

The gist of the blog is that perimeters are easy, when your design is a box. It’s when all these angles start to go out or in that crap happens. Normally I use 3 perimeters but when printing vases, I use a single wall. But it fails a lot.

And here’s why: PERIMETERS: 2 vs. PERIMETERS:5 Rising angle: 13°; Layer height: 0.2 mm

Perimeters 3d

Yep. Air Printing. A single wall even at max resolution, well, sits nowhere. Whereas if one has enough perimeters, things will build up nicely. Here’s a snapshot of it, but for a detailed look, here’s the main link to it.

Perimeters curved face

Ah ha. One needs more perimeters and therefore VASE mode in Slic3r is very limited. Then I got thinking that when I looked at some of the samples on Thingiverse people had printed out, they looked like single wall thick. Which is where I got my second nugget.

Apparently Simplify 3D and CURA have the smarts to calculate extra perimeters in these areas and they do. Slic3r on the other hand adhere’s to exactly what you tell it to do. Not what you expect it to do…

Quite a well written blog article and I encourage anyone who has ever suffered these symptoms to read it. Worth your time.

10
Jul

ESP8266 Breakout Programming

Last year I sourced a bunch of ESP8266’s for programming but wasn’t excited about them enough until the Arduino IDE was expanded to support them. Then suddenly all of these inexpensive WiFi things became extremely versatile and useful.

This is the first one I started with, but of course I did some modifications to it. Like rip the battery box off and replace the battery wires with pins.

Esp8266 development board esp 12 er dp8266esp12

The result of the simple modifications was a voltage divider on the RX input because the USB to Serial adapter is tossing out 5V and the ESP8266 is a 3.3V denizen. Two resistors (1K and 2.2K) are used to do the job.

On the PCB’s, the terminals for RX and TX are labeled in reverse. In other words they tell you where the signal is supposed to go on the Serial adapter, not what’s coming out of the 8266.

The second mod was a NC push button on the Vcc line. The 8266 board has its own 5 to 3.3v regulator but in order to program it from the Arduino you need to put it into flash mode in a specific way. If you omit the normally closed push button, just disconnect Vcc at the pin.

ESP8266 Connections

Programming Step 1 – disconnect Vcc at the breakout. Place the jumper on the two pins on the bottom of the breakout.

ESP8266 Step1

Programming Step 2 – Connect Vcc to breakout board. Remove the yellow jumper from the PCB.

Esp8266 Step2

The ESP8266 breakout is now really for you to program it.

Programming Step 3 – in the Arduino IDE the setting for the breakout is the Adafruit Huzzah one. The port will be whatever USB to Serial board you have plugged in.

ESP8266 BreakOut Programming

And that’s it. Open an ESP8266 sketch, compile it and you’ll see the little blue LED on the ESP8266 flashing away like crazy. When it’s done the ESP8266 will automatically start running the code you sent it. It doesn’t reset when you connect the serial monitor to it like the Arduino’s do.

If you have the same breakout board, here’s a sample sketch for you to send to the board. It will sort of simulate the old Knight Rider bar graph and if you cover the photo cell it will change the speed of the cycle.

Knight_Rider

9
Jul

3D Print Fixin’

Sometimes it’s the simplest things, or things that look simple, that will rise up and confound us. At which point all of our accumulated knowledge is about as useful as an umbrella to a fish.

One of the makers at our space was having troubles printing a “Slimer” from Ghost Busters so I suggested he send me the file or link and I’d have a look at it.

First thing was to open the Slimer in Slic3r. And realize in .5 seconds where all the problem areas are.

SLM Step1

For example, there’s the cavernous mouth. 3D printers truly suck at “air printing”. So that throat tonsul is doomed from the get go.

SLM Step2

I won’t mention the second area, the fingers. With the tips of the fingers there’s no firm attachment to the bed and any bump at all and…well…poor old Slimer is going to have some digit problems. And everything there after that connects to it.

SLM Step3

Generating Supports

Slic3r does have built in support generation, but trying to get those supports out from inside Slimer’s mouth would probably qualify you as a budding Orthodontic wannabe.

So off to AutoDesk to find Meshmixer, download, install. Use the IMPORT function in Meshmixer to load in the STL file.

SLM Step4

And BINGO. If we weren’t paying attention, we’d see that Slimer is getting away. The red dot marks the center of the build area in Meshmixer but Slimer is way off that.

SLM Step5

So like the most dismal words ever heard by an Amway salesperson, “No Soap”. We have to fix this first, and thus, we bail out of Meshmixer for the moment.

STL Repair

The best piece of software for “fixing” bad STL’s is netFabb (free)…Go find, download, install, get running….then head to the project menu to open the troubled Slimer.STL file.

SLM Step6

netFabb will display Slimer, usually in a glorious green colour, but we’re going to “fix” him so who cares.

Look for the + sign (think of the red cross) and click on it.

SLM Step7

Good. Unfortunately that didn’t really fix anything, just started the process. We need to continue so head down to the bottom right corner of the display and look for “Automatic Repair”…and click on it.

SLM Step8

A dialog will show up with two options. Default repair and Simple repair. I used to use Default, but found that Simple repair works 100% of the time (better too)… so click on Simple Repair and then the Execute button…(don’t worry about executing Slimer; he won’t mind).

SLM Step9

You’ll notice the display sort of changed for a split second and what has happened is you have TWO Slimers. The original and the new one. We need to get rid of the first one (original) leaving only the repaired one.

Bottom of the main display look for the Apply repair button, click it.

SLM Step10

You’ll get a dialog asking what you want to do with the two parts. We want to remove the OLD part, thereby leaving the new part.

SLM Step11

So WooHoo, we’re done right? Yeah, not so much sparky. We have to SAVE the repaired design. Like this (a CONTROL CLICK for the Mac guys):

SLM Step12

Now the STL is repaired. And this is how you’ll repair any STL file that has issues. It works way better than the auto repair in Slic3r so it will pay you to learn how to do this.

Back to Supports

Remember when we last opened Slimer in Meshmixer he didn’t center on the print area? News flash for you. He still doesn’t. netFabb doesn’t auto centre, it assumes we know what we’re doing. And in some cases, that’s a good assumption. In this case, ah, no.

So how do we center it? Easy. Open the repaired STL file in Slic3r. Then use the EXPORT STL button in Slic3r to save the centered STL

SLM Step13

Exit Slic3r and get Meshmixer going again. Now, before you complain that you didn’t need to “fix” Slimer with netFabb at all and you just wasted your time, the point was to show you HOW to fix if need be, so you learned something (you did pay attention didn’t you?) so, your time was not wasted and in the future you may even thank me. Silently. Under your breath. Begrudgingly. Or not.

Importing Slimer repaired and centered in Meshmixer now looks correct. The red dot is close to where the good Lord split him so he’s in the center. If you catch my drift.

SLM Step14

On the left side of Meshmixer is a bunch of icons. Because someone failed their GUI design phase I think, but, well, an icon is worth 1000 words, hence click on the Analysis and then Overhangs.

SLM Step15

A dialog will display where you can make custom overhang settings or just use the defaults, as most of us do. The button labeled Generate Support is the one we want. Click on it.

SLM Step16

You’ll see a progress bar, some messages (or many in this case) about “nodes” and “pruning”. In a period of time Slimer will appear with supports. These are not permanent at this point. If you want to delete one or many, hold the CMD key down and click the support to make it go away. If you make a mistake (and how else would you have gotten to this blog in the first place eh?), CMD Z will UnDo and put the support(s) back.

SLM Step17

If you notice areas on the design are in RED, those are the areas that are going to have printing problems. Due to the angle of the printing (less than 45 degrees for example) and that’s where support(s) will be of benefit.

When you have the supports left you want, click the DONE button and then use the File Export item to save the supported STL file.

SLM Step18

Supports Complete

When we reopen the STL problem slime ball in Slic3r, he’ll look a lot different. Like he has grown way more teeth. Really those are just supports.

SLM Step19

Those small supports will break off quite easily when the printing is done, yet they do provide more that adequate support during the printing phase.

Summary

This lesson has been brought to you by the … oh wait, wrong program… hopefully you’ve gained some insight as to how netFabb repair and Meshmixer support works and you’ll be able to easily use them both when you need to. And yes, both programs do a LOT more, but just having a good understanding of how to fix things is a huge leap. Forward. Up. Okay, maybe just a bit of a wiggle then.

Having gone through all of the gyrations of fixing this design, to print, as you see it, there are other ways to do it as well. On Thingiverse, search for Minions. You’ll notice that they are printed in two halves and glued together. There is no reason why Slimer couldn’t benefit from the same procedure.

A simple task in Tinkercad to split, save the halves, perhaps fixing in netFabb (Tinkercad can screw up when generating the STL file) and then printing. My thought is it would be a lot easier printing. Or not. Honestly, I haven’t tried it, that’s an exercise for the reader. And yeah, you might miss this nugget if you just looked at the pretty pictures…

14
Jun

Clicgear Brake Hub & 3D Printer

The amount of golf and my friends and I play would not be what you’d class as “normal”. From about March to November we get out at least twice a week and for many weeks in there, three times. So 70 to 90+ games in that time frame.

While this obviously takes a toll on our sanity, it also takes its toll on our equipment. Specifically the golf carts. No, we don’t count golfballs in there because they aren’t really lost, just misplaced until someone new finds and adopts them. Yeah, that’s a totally different thing…

Our cart of choice is the Clicgear series. Best fit in our vehicles, nicely designed for the most part and easy to push. The earliest is version 2.0 and the latest is the 8.0 or the 3.5+. The V8 is a different animal because it’s a four wheeled cart, and keeps the clubs more upright, plus, oddly enough, it’s easier to push.

With the 2.0, 3.0 and 3.5 series they all share a common weak point. Or design flaw if you want to call it that. The brake hub. It’s a dogged plastic hub that is really not all that hard to break.

Clicgear Brake Org

So in a matter of time, it ends up looking like this:

Clicgear Brake Smashed

Replacement parts can be ordered from Clicgear but shipping to Canada is stupid. A trip to the local Golftown resulted in the “silly” being continued because they won’t order one, you have to buy a dozen.

A cruise around Thingiverse led me to someone who designed a brake hub for 3D printing. I downloaded and printed it out, and it didn’t exactly fit as well as I hoped

When I checked some of the dimensions they appeared correct except for the gaps next to the 2mm pins. Plus there was a gap in the center that while matching the original hub, did little so I remixed, adjusted the gaps and filled it in slightly.

Clicgear Brake Top

And the bottom (where the pins and gaps have to be exact):

Clicgear Brake Bottom

Printed at .2mm, 100% infill, with supports.

A simple matter to remove the nylock nut that holds on the wheel, remove the old brake hub and replace with the new one.

Clicgear Brake

While checking the hub for fit, I noticed that the cable is about as far out of adjustment as possible and yet still work. The way all of our carts seem to come from factory, where I’d say they have a quality control issue or two, is the dog barely catches the tip of the hub part. Thus considerable force on the hub.

The brake dog that moves is shaped to fit snugly into the brake hub, but every one I have looked doesn’t fit properly. If you have a Clicgear cart, I’d strongly suggest you check out the brake adjustment and make sure it is completely engaging and disengaging properly.

I’d printed a couple of spares now so we’re all good to go for a couple of seasons. Now if I could just find a way to print Titleist NXT Tour golfballs I’d be set….

3
Jun

Simplify3D – Delta Printer

Having logged over 1700 printing hours on my delta’s means that I have more than just a passing glance and familiarity with the operation, firmware and supporting software.

Having said that, I’m always on the watch for something that works better than what I currently have/use. Be it a firmware, mechanical part modification, or support software upgrade. It was with that in mind that I decided to try Simplify3D. Since there is no “trial” version, the only way to get it is to pony up the $149USD and buy it. Which I did.

The whole premise being that whatever GCODE Simplify3D spit out would be vastly superior to anything from Cura, Kiss Slicer or Slic3r. I know Slic3r extremely well so this sort of advertising statement should not be taken lightly.

Keeping all this mind, this is my opinion of the software, from strictly a delta printer users point of view. Cartesian printers could be a completely different kettle of fishes. I don’t know, I only own delta’s.

Buying and Installation

Once you PayPal the rather princely sum for the software, you’re given a link to download the software and you set up a cloud account with Simplify3D. Mainly for updates as I read it so you don’t need a full time connection to the net to use the software. I did need a connection initially to get the software registered so I could use it.

All in all, straight forward and painless.

Setup

When you first run the software you’re given a choice of printer profiles to choose from. And it’s NOT a small list by any stretch. At least until you start to count the Deltas in the list. Then the list is very small indeed.

To put this in perspective, one needs to remember that delta printers are not the printer of choice. The last “stat” I saw was that delta printers were the #1 choice for a kit and satisfaction but still only occupied less than 20% of the total printer market. In Simpilify3D’s printer support list, this is reflected.

Simplify3D’s software, which I’ll refer to as S3D after this, when running sort of resembles a mash up between a typical slicer and something Autodesk would do for a UI.

Simlify3D UI

S3D refers to your printer settings, which is actually more than just printer settings, as processes. You know, maybe because they didn’t know how to spell profile. Or processes sounded more impressive. The quick start guide implies that you can even select multiple “processes” when you slice. The quick start guide also completely ignores telling you just what might happen should you do this.

The model list is merely the bunch of STL files you are going to print. But yeah, models sounds more impressive than “objects” or “Tessellation”…

The toolbar is S3D’s nod to Autodesk.

S3D’s whole claim to fame is based on the processes as noted, and this is the first red flag that went up in my mind. I have custom built delta’s, not a Kossel MINI, Kossel MAX, or Rostock.

I selected some of the “prebuilt” processes for the delta’s and it was pretty obvious from the get go, those were token gestures at best and if something was actually printed it was more good luck than anything else. None the less, I did try printing with the various processes. I have the failed prints to show for it.

Custom Process

About 4 hours into seeing what S3D could and couldn’t do, and I decided the only way to make it do something is start and create a custom process (profile). Five hours later I was still working and testing. Because I’m slow? Nah, because the documentation that explains all the settings is so poorly written that it’s two points below a joke.

And there are TAB’s of settings, more so than Slic3r. And not exactly arranged in any logical manner. Plus some programmer decided that numbers were evil so you need to enter “percentages”, like for the first layer start height. Want it to start at .34mm, enter in 113%. Like that’s intuitive.

In the Preferences you can change the mm/m to mm/s and spend a lot of time trying to figure out where Slic3r settings might fit into the S3D settings. Because, there’s no import or conversion from a Slic3r configuration to S3D. Big oversight there to my programmers mind.

Even using the built in processes, when the print job was done the head didn’t home. It just sat on the print. And oozed. I have no idea why all the delta processes would ever want to do that.

Eventually I threw up my hands in surrender. 11 hours of trying to get a decent print and no soap. I emailed the S3D folks and asked for a refund.

Tech Support

I didn’t get a refund, what I got was a reply email that asked me what printer/kit I had and that they would create a “process” custom designed for my printer. All I had to do was provide them with my Slic3r config file and they’d transpose it for me. I sent them links to my delta’s specs and Slic3R config and within the day I had a profile back. They said that they have built a number of deltas and were familiar with them so

Sorry guys, but after looking at your “process” attempt I have to call BS on it. Anyone who owns a delta with a bowden tube knows that retraction is extremely important. The process I was provided gave a 1mm retraction at 30 mm/s. Bowdens want 3-5mm of retraction and 60-80mm/s.

Extrusion is set at .9 by default. Which made no sense at all. Extrusion width at .4 and on and on the goofy settings went. I seriously wonder if they even looked at the Slic3r config file.

Oddly, no one who responds to you via email from S3D tech signs their email so, I’m just going to call him, Blobby. Because that’s what the prints looked like. So Blobby, you get a fail. Time to work on your resume.

A Spaghetti Western

This is what S3D reminds me of.

The Good: opens any STL, repairs where need be, easy positioning. Slices any model in under a second. Creates GCODE files in seconds. Nicely done.

The Bad: stupid settings that should be numbers not percentages, lousy user manual, poor delta support.

The Ugly: Every print made from the generated GCODE.

In spite of the fact I set 3 perimeters for a prime, S3D decided, on its own, that I only needed two. And if you think Slic3r has sporadic moves, S3D is like a deranged hummingbird.

You can see from the first layer, the infill doesn’t meet the outline (and I have the overlap set to 34%), I’m using the “Blobby” process, and it’s going to be a fail from the start.

Outline Fail First Layer Fail

Looking at the finished print with the tech designed process:

First Layer Fail

Yeah on the top is the primed perimeter that is still attached to the main body of the print. Retraction is a big issue, and yes, that’s an easy fix. Less easy to fix is the fact that the infill doesn’t hit the outline. And this is caused by either under extruding, or a speed that’s too fast.

Of course when the extrusion defaults to .9, yes, then that could be a possibility. Dumb. Da. Dumb. Dumb.

For the speed, it’s interesting to see that outlines are variable speed. The inner most outline is done wiki wiki. When S3D gets to the outer most it slows down to what is in the “process” setting. I saw no way to get it to do all the outlines at the same speed.

S3D also fails miserably on bridging. Look at the top and you’ll see the infill doesn’t work. It doesn’t touch the outlines. So you have to print a couple of layers to get it to bind.

Bridging Fail

Blobby retraction settings are abysmal. 1mm at 30mm/s is pathetic. The gold one is a Blobby setting, the red one is from Slic3r with my settings. Notice the head is attached to the fin. That’d be wrong.

Clear Slic3r Superior

Finally Refunded

After three days hounding them I finally got a refund. So to their credit, they stand behind their “if you aren’t happy within two weeks we’ll refund your purchase.” promise.

I’ve uninstalled the software, tossed it in the trash. I miss it about as much as a root canal.

My Thoughts

So, exactly who or what market is S3D aimed at? One look at their web site and this graphic should give you all the info you need to answer that question.

S3D Printers

Yep. Main stream Cartesian printers that, should they become any more plentiful, we’ll have to develop a spaying program for. For the delta crowd and out of the box thinkers, nah, not so much.

If you’ve spent time and learned the nuances of Slic3r and tweaked it (which really isn’t that hard either), I saw that S3D had one advantage in that it allowed you to place custom supports where you want them. You know, if you don’t want to run MeshMixer and do the same thing.

Granted S3D did slice anything I threw at it in a heart beat, but none of the GCODE it created resulted in a useful print. Which kind of negates the slicing speed.

Essentially the way it’s marketed it’s for the plug and play end user, who is so fed up or frustrated with other slicers that just about anything short of a Craigs List ad for their printer would be an improvement.

20131008 004953

Now I’m sure you’ve all seen a lot of examples of failed prints, and for me, I have a fair number of my own that I can contribute as well. But even with the simple mode set in Slic3r I was getting better results than anything S3D was able to generate.

Lastly the CNC tool paths aren’t optimized in S3D. It looks like it’s playing “Whack A Mole” on your design because it’s all over the place. More so than Slic3r and that really surprised me. If you ever want to see what an infill should fill like, head over to ANY tee shirt shop where they print custom crests/logos and watch an embroidery head lay down stitches. The software avoids filling back on itself, jumps (called jump stitches) are kept to a bare minimum because they have to be manually cut out when the design is done. And yes, embroidery designs are multi-layer. You lay thread on top of thread in many places.

My dream is that someday a programming in the 3D print world will be able to replicate what’s been going on in the embroidery industry for a couple of decades when it comes to optimization and fills. Until then, we will just do the best we can with what we have. For Delta printers, S3D sure makes Slic3r look great.

19
May

Just spoolin’ with ya

After having constructed more Kossels than the average person, one thing that annoys me about them is the spool handling setup, or lack thereof.

Normally what you get is something like this:

Kossel Peg

Which in all fairness does work, but it sticks out some place, usually in the wrong place. Filament spools come in every size width and you need a long peg to handle those Kg spools.

Thus, I’ve never been a fan of them.

Next up we have the spool rollers like this one:

PLA spool holder

Now one would think these would be the perfect holder. And they are. Right up to the point that your Kossel does a massive retract and extract. And then this spool has a nasty tendency to unspool itself from the momentum. I built one of these but used skate bearings on the ends. I was checking the printer and found it had unwound several feet all on its own. With bearings it was frictionless. Not good.

The variation of this is the horizontal spool roller that sits at the top of the Kossel.

Kossel Horizontal

Again it works but I have the power supply mounted on the top of my delta so I don’t want the power supply fan restricted by a big reel of filament.

So this brings me what I worked with, when I actually worked for a living, a straddle winder. Course when I worked with it, the rolls were a lot larger than a 1Kg roll of filament. But the principal remains the same.

Stradle winder

Scanning through Thingiverse will give you any number of these types and one by AirTripper has been one of the best.

Airtripper s Pocket Filament Reel Rollers by Airtripper  Thingiverse 2016 05 19 15 59 11

I built one of these early on and have been using daily ever since. When I built my second delta printer I decided to see what else I could come up with. Something that used less bearings for example.

This lead me to a design called “Spool Foot” on Thingiverse.

Spool foot

It uses four 608ZZ bearings, some 8mm nuts and bolts. So I printed one. And immediately found that with the foot print of the cradles it would not go close enough together to fit my narrow spools from eSun. Opps.

Over to Tinkercad and made some modifications.

IMG 1454

With the offset foot design, I can move them very close together. I also decided to use 5/16″ x 1 1/4″ bolts. The final design looks like this:

IMG 1455

The only thing that moves is the bearing, the filament spacers either side of that clamp it in and keep the filament spool in alignment. It works super.

If you want to build your own, here’s a link to my design

10
May

Kossel Fan Update

The dual hot end cooling fans have been installed on Rocky & Bullwinkle for quite a while now and they are working to cool the prints better than without fans.

Having said that, remember the old adage that you don’t get something for nothing? Well, turns out there is a side effect to using fans, or rather adding anything to increase the mass of the hot end. A perfect example is in the photo below. Specifically the vertical lines you see on the right side of the print.

IMG 1386

I normally have the perimeters set to 3 and what you see is a result of the rapid movement of the head for the perimeter and then the acceleration as it moves away from the “jerk” point. Call it a ripple or ringing effect. What happens is in a very fast move, the whole mass of the effector jerks, and then the vibration tends to die down and you end up with that little wavy effect in the photo.

Even without the fans, when I went back through some of the prints I’d made with a bare minimum hot end (just a fan shroud and fan), there were still some vibration artifacts.

Truthfully, I hadn’t really even noticed this until I was printing out a CODEX that consisted of a numbered wheel. I have rotated the picture 90 degrees clockwise so keep that in mind when you’re looking at it. As it comes off the printer it looks like this:

IMG 1426

The “4” on the left is with some Marlin firmware adjustments, the one on the right with the ripples is where I was normally printing.

IMG 1427

Another example is the “7” on the same wheel.

IMG 1424

The only way to fix the ripples is not really to slow down the printer per se, but to tinker with the “jerk” and “acceleration”. In the Marlin firmware the section you want to tinker with is (configuration.h):

// default settings
// delta speeds must be the same on xyz
#define DEFAULT_MAX_ACCELERATION      {3000,3000,3000,3000}    // X, Y, Z, E maximum start speed for accelerated moves. E default values are good for Skeinforge 40+, for older versions raise them a lot.

#define DEFAULT_ACCELERATION          3000    // X, Y, Z and E acceleration in mm/s^2 for printing moves
#define DEFAULT_RETRACT_ACCELERATION  3000    // E acceleration in mm/s^2 for retracts
#define DEFAULT_TRAVEL_ACCELERATION   3000    // X, Y, Z acceleration in mm/s^2 for travel (non printing) moves

// The speed change that does not require acceleration (i.e. the software might assume it can be done instantaneously)
#define DEFAULT_XYJERK                20.0    // (mm/sec)
#define DEFAULT_ZJERK                 20.0    // (mm/sec) Must be same as XY for delta
#define DEFAULT_EJERK                 5.0     // (mm/sec)

The values for default acceleration and XY and Z jerk on the “wavy” examples are shown above.

When I started testing, I changed first the Jerk, and it helped a little, then changed it back and change the acceleration default and it helped a little. What I found at the end is that it’s a combination of both that worked best. And of course it depends on how badly you have those vibration lines to start with…

For the numbered rings with the least amount of ringing, I used a default XY and Z jerk of 10, and a default acceleration of 1000.

#define DEFAULT_ACCELERATION          1000    // X, Y, Z and E acceleration in mm/s^2 for printing moves
#define DEFAULT_XYJERK                10.0    // (mm/sec)
#define DEFAULT_ZJERK                 10.0    // (mm/sec) Must be same as XY for delta

The result:

IMG 1423

Yes, there is still a seam, but the ringing is a LOT less than the original.

The downside to having cooling fans on the hot end is that when you change the jerk and acceleration, you slow down the print job. The first print was 1:31, the second was 1:42. But if it’s quality that you’re after, 10 minutes seems very little to give up.

While I was testing, I also decided to change the perimeter settings in Slicer from my usual 3, down to 2. The idea being that it might help the hot end jumps. Safe to say after testing a number of prints, the number of perimeters doesn’t matter squat as far as I can see. It does help slightly with heat on the overhangs but that’s about it.

Regardless of the printer type, the head is moving in one direction and changes to another, there’s always some backlash. Vibration and ringing on the print are the result. If you want quality, especially with an object with writing on it, speed is the enemy of quality.

Maybe someone will come up with a vibration attachment so one can really fine tune for maximum speed while maintaining minimum ringing. Until then, like most others, I’ll just bumble along the learning road.

9
May

3D Printer Nozzles Part 2

A few days ago I was testing out some printer nozzles and at the time I had some perfect results with the largest clunkiest one in the lot. I.e. the left most one.

IMG 1347

All of the nozzles are .4, 6mm thread, typical MK8 style. The difference in all is the inner chamber and the outside nut size.

  • Smallest ones, the two on the right, inner diameter of 1.85mm, nut size of 6mm.
  • Middle two, inner diameter 1.91mm, nut size of 7mm.
  • Left “monster”, inner diameter 2.25mm, nut size 7mm.

I did a lot of test prints and some various “worst case” prints that I use for testing everything from coverage to bridging on the printers.

And the term, “one size fits all” started to quiver on shaky ground. While the monster nozzle did some designs well, as in large designs, with smaller designs that had small circles and such (think standoffs) that blunt nozzle tended to heat the surrounding area too much and even with fans the result was poor. At best.

I swapped out the monster nozzle with one of the middle ones, 1.91mm inner diameter, 7mm nut size, 12mm length. And run many of the same prints the first nozzle had problems with. While the same issues did appear, they were far superior. So much so that I left the nozzle in and am still using it.

So there ya go. Spend about 16 hours testing nozzles and what I can say is that the best all round nozzle I have found is the middle ones in this photo:

IMG 1349

To recap the specs on it, inlet diameter 1.91mm:

MK8 Nozzle

Length is 12mm. Seems that on eBay now most of the ones I found are 13mm in length.

29
Apr

TFT GPS CAT Clock

I made a clock for the granddaughter a couple of years back and it’s been working fine until a couple weeks ago. The display was fairly small TFT 1.8″, consisted of a DS3231 clock module, power converter, and Arduino.

Each day the display would come up with a witty quote that was read from a SD card. Optionally there was a monthly calendar that would toggle on/off if a button was pressed.

IMG 4981

Keira mentioned that although she used to like a “night light” in her room at night, now she didn’t want any light at all. I tried, unsuccessfully, to modify the LED backlighting on the TFT to get it to turn on and off. She just laid the clock face down at night to stop the light as a stop gap.

When I got the clock back from her, the DS3231 backup battery was dead, and the chip itself was generating random times and dates. Which were probably correct somewhere in the world, but not in our locale.

Hence, time to build version 2. The first order was to find out what Keira liked and disliked about the clock. The first like was the calendar portion. The strong dislike was the TFT backlighting.

Time to assemble the parts. An Arduino MEGA, breakout board for the TFT display and a high resolution 480 x 320 3.2″ display. To make darn sure the time was going to be accurate, I added a Skylab GPS module.

IMG 1331

The reason for the 3.2″ high res TFT was that Keira is a cat lover. Lynx in particular. My original idea was to have a background picture, and draw the time/date over top of the display. What I soon found is there is no functional library that does this sort of blending of text on graphics. Granted I could write one, but I decided to keep it simple.

I soldered wires directly on to the GPS module, sandwiched the boards together and presto, a relatively compact clock.

IMG 1333

Rather than add a bunch of push button switches, I used a couple of 3mm round head screws with the ADC touch library. I soldered two wires on the Mega’s A0 and A1 pins to use the library. If you noticed the display I am using also sports a touch screen but I didn’t like the idea of finger prints on the display so I didn’t use it.

The display is a Cold Tears 3.2″ TFT 480 x 320 display. Very nice colour and, when I looked at the back of it, there is a control for using PWM (pulse width modulation) to control the brightness of the display. What is not clear is how you make it do this…

In reality you need to unsolder one jumper on the TFT PCB and then on the adapter board PCB you need to add a short jumper wire because they never put a trace/jumper on the board to do it. Once done, pin 44 on the Mega with a PWM signal will control the brightness of the TFT.

Next up it was off to the internet to find some cat pictures that would scale nicely for the display. I had previously written some software that would open a graphic, scale it for a TFT display and then save it in RAW format so the UTFT library would read the raw file and display it. The graphic size that scaled best was 600 x 400 so that’s what I used as the exact size in the search.

Scaled with the date/time showing:

IMG 1334

I purposely looked for images that didn’t have something on the bottom so the date/time wouldn’t overlay the important part of the picture.

With the backlighting on the TFT, it wasn’t until I built my own Tardis clock for our bedroom that I fully understood just how bright even a dimmed LED can be. Let’s just say I completely agree with Keira on the lighting.

For a case to hold the clock, well, it helps to have a 3D printer. I designed a case in Tinkercad that would hold the clock, and then a separate base to stop the clock from tipping over. You can see the two “touch” screws at the top right corner of the case. Those are used to kill the backlight on the TFT and to toggle between the cat/time/date and monthly calendar views.

IMG 1351

There are 100 images on the SD card mounted on the back of the TFT display and each day at 2am, the clock will pick another photo at random. Since the clock is GPS smart, it also nows daylight savings time from regular time.

While Keira can turn the TFT backlight on when she goes to sleep, I have it coded so that at 7:30am in the morning, it will turn itself back on for the day. Or you can turn it on manually before that time.

For anyone who might have noticed that the dim image in the last photo looks like a golf club, well, I AM an avoid golfer, I do things a little different. But I did keep with the “cat” theme….look at the brand name and logo on the club head…

IMG 1352

26
Apr

3D Printer Nozzles

With just under 1300 hours on Bullwinkle (my first Kossel) and about 20 hours on Rocky (my second Kossel) you’d probably think that I’ve learned all there is to know about…well…3D printing.

In actual fact, the longer I am in this hobby; if one can call using a heated inverted tripod to drool PLA around a heated bed, the less I realize that I actually know. Oh sure there’s some obvious stuff I have learned, but sometimes the things that I’ve never paid any attention to are rather important.

As the topic suggests, I’m going to write about nozzles. I have ordered more than just a few off eBay because I was told that they wear out. What was failed to be mentioned was at what point they actually wear out. With as many hours on them as I have, I would have thought they would be wore out completely now. Yeah, not so much.

Thus I have not managed to wear one out yet. I have managed to plug them though. Using a small butane torch to blast the filament inside to ashes works fine to recover the nozzle. Although I have to admit for the price of the butane torch, you can buy a few replacement nozzles.

For my Kossels, I have used MK8 styled nozzles. I changed one on Bullwinkle at about the 700 hour mark, so 500 hours ago and it’s still printing just fine.

A month ago I built Rocky. Overall a better build than the first printer largely because I know what to mind for when building one now. None the less, with the same firmware settings, I was having some issues getting the filament to flow properly. When I got the extrusion right, the extruder would skip (it clicks when it skips from the bowden tube back pressure).

Didn’t make a lick of sense to me because both printers are identical builds for the hot ends, bowden and extruder. Firmware steps were also the same and when measured, ask for 100mm of filament, I got 99.91mm on average.

Cranking up the tension on the extruder resulted in the Bowden tube pulling the top pneumatic fitting right out of the extruder housing. So yeah, it takes a whack of force to do that, but I dood it…

After re-printing the extruder, did I mention it’s handy to have two of these so on can fix the other? No, not what my wife thinks either…:-) Any way, with the new extruder I started to look at why the hot end wasn’t working right.

I already know that the temperature thermistors on hot end can vary, sometimes a considerable amount (+- 8C). But that did’t seem to be the problem when I measured it with my Fluke temp probe.

Nope it was something else…

So I thought, what the heck, I’ll change the nozzle. And low and behold it suddenly worked perfect. If you’re thinking that the old nozzle might not have been the right size, I have a .4 drill bit that I run through all my nozzles before pressing them into service. Hence, it was the correct size.

None the less, the first layer pattern looked completely different. As in GOOD different compared to the old nozzle. So I checked the type of nozzle I put in, compared it to my stock of nozzles and realized, by shear luck I’d snagged a great nozzle.

Here’s my line up of nozzles that I have in my parts trays:

IMG 1347

Kind of hard to believe those are all MK8 nozzles. But they are. All .4mm. The three nozzles on the left side of that picture are 7mm ones. The two on the right are 6mm ones and the type that came in my Kossel kit.

It’s quite easy to see that for as far as mass goes, the nozzle on the extreme left in the picture has the most mass. Which means it’s going to hold its heat quite well and it’s going to transfer that heat to the filament as well.

Looking down at the tops:

Nozzle Top

Again, easy to see where all the mass is. In fact, so much mass that they grind off the top to keep it at the 12mm overall height.

So back to my nozzle that works so well, it’s the one on the left. Not only does it have large mass, but there’s another little surprise when you look at the inlet side of the nozzles.

IMG 1348

That’s standard 1.75mm filament. The four nozzles on the right vary in the inlet size from 1.84 to 1.91mm. So 1.75mm filament fits in with a bit of wiggle room.

However, the nozzle that works the best for extruding the proper amount is again, that extreme left one. The inlet size on it is 2.25mm. The filament has LOTS of room.

IMG 1349

While it looks like an optical illusion, those right nozzle inlets are darn near the same size as I mentioned, but that left one, huge. Like a cave.

What I think is happening is that with the larger mass, and bigger “reservoir” the heat is transferred better to the filament and it flows out very nicely. Whereas the smaller ones don’t. In my experience any way.

I’ve noticed that some of the eBay sellers have started to put inlet sizes on the nozzles they sell. Today I spotted one that had 2.5mm inlet. Would it better as good or better? No idea.

If you’ve been experiencing extruder problems, i.e. clicking, under extruding, have a look at that nozzle. Might be worth ordered a couple of the .4mm nozzles but with more mass and a bigger inlet. If you want to print faster, this might also go a long way to allow you to do that. All one can do is experiment.

One note of caution, if you do change the nozzle, remember you might have to re-level the hot end. If you can find the same 12mm length nozzle though it’s not going to be much of a change and the benefits could out weigh the time it takes to re-level.

24
Mar

Kossel Fan Verdict – Success

Thus far I have six versions of the fan structure for the Kossel. Each one has been an improvement over the previous version so, much like software I was starting to think it would never be done.

Today, I put that concept to rest. With frogs. And not little frogs, 80mm tall frogs…

See, printing critters is the tough part when it comes to 3D printing. There’s always some overhang or angle that is not going to be printer friendly. At which point you have to decide if you want supports turned on in the slicer software, or you change orientation of the print, or, you just go for broke and hope.

So we start with these two bored looking guys. Who resemble me while I’m waiting on a print job. You can find the original here if you want to print it out yourself.

IMG 1277

The green frog is printed with MG Chemicals green PLA (no, not Soylent green! People!), the white frog is printed with MG Chemicals white PLA. They do have somewhat different flow characteristics. As does most PLA. But this is not so much about the PLA quality, it’s about a fan.

My fan design, below, is designed to replace the standard fan shroud in the Kossel FVM kit. It is fairly sturdy, uses the same axial 40x10mm fans as the cooling fan in the present shroud. The fans are held in by some 3mm hex head screws that are screwed right into the plastic. I generally drill them out with a 2.5mm bit so they thread in easier.

IMG 1284

If you look closely at the bottom of the new shroud you’ll see a couple of circles. Those are adjustable louvers for aiming the exhausting air. From underneath they look like this:

IMG 1285

They are a SNUG fit too!

I made them adjustable originally so I could “aim” the airflow, as it turned out, I really didn’t need to do that. Just make the slot so it pointed at the tip of the nozzle. Hence, set once, forget them.

Testing – Green FROG both fans 50% speed | White Frog – NO FANS

The SAME print file was used for the frogs. Any difference you see in the print quality not fan affected will be the different flow rates of the PLA themselves. And again, not the point here.

The frogs arms are the problem areas. See the angle the arms go up? Yep. The white frog has problems with laying hot PLA on top of the HOT PLA.

IMG 1279

A better look at the back of the same arm (sorry it’s not vertical, white doesn’t photograph easily).

IMG 1281

Pretty easy to see that the heat was causing some issue, or, maybe it’s just a 97 year old frog. Whatever.

The other arm now. Check the elbow and cheeks (I don’t know if frogs have elbows so don’t start with me)…

IMG 1283

And

IMG 1282

You can see even the green frog had some problems with the under arm area (bad deodorant?) but the white with no fan was much worse. Not to mention the mess where the frogs hand is at the side of his mouth (check his thumb).

For the green frog, maybe more fan would have helped with that one arm, or not. It’s over a 3 hour print, I don’t want to keep doing it. It’s suffice to know that, yes, fans really help.

So maybe you want to make one for yourself. If that’d be the case, here is the link to my Kossel fan. Feel free to use it and I hope it works as good for you as it has for me. Oh, I am driving it with a stepper driver PCB and an Arduino MINI for speed control.

20
Mar

I built a Kossel

Yep. That’s right. I built a Kossel. For anyone that knows me, this news will not come as any surprise since they know I built one in June 2015. It took me three weeks. With many hours every day. A number of good stiff drinks. Long quiet walks on the beach.

Although advertised as a “kit”, in all honesty, it was a box of parts with a link to an online manual that didn’t reflect the parts that came in the box. Which made the assembly and calibration one of the most frustrating things I’d ever experienced. Apart from wanting to heave the whole thing in the garbage bin (not sure which parts of it would be adequate for the recycling bin), I started to find the humour in building it.

IMG 0119

As I remember the build, two things were obvious. First, this wasn’t a kit by any stretch of the imagination. Second, although I’d label myself a “maker”, what I knew about 3D printers on a scale of 0 to 10, was running at about -5 (that’s right MINUS 5). Mechanical I know some of, electronics I know more of.

My stubborn and “want to know what makes it tick” attitude determined that I would indeed learn the thing inside, and out. Thus I didn’t give up. I got it working the absolute best that it can work. I’ve even bling’d it out with my own add ons.

So fast forward to today. Ten months down the road. Over 1100 hours of printing time. And the printer, as of this minute, it printing something else for me. That’s right, in spite of it all, it’s working like a champ. Who’da thunk.

Back to the topic, I built a Kossel. Actually, I’ve built TWO of them now.

I printed out a complete set of parts for the FVMakers “kit” in MG Chemicals GOLD PLA (MG has some VERY nice deep and vibrant colours in PLA!). Rather than just build the thing, I decided to do a photo build of it. Not just “this part goes here” but building it the way a real kit would be built. I.e. you build in subsections and then assemble the subsections.

The fully assembled and calibrated Midas is for sale from FVMakers (if you’re interested ask them about it by name) so I didn’t built it for myself. I built it for someone get as many hours of enjoyment from as I get from my own.

In two evenings the complete mechanical sections were assembled. Two more nights for wiring and some bling and it was done. Bling? Yeah. Kossel with power supplies hanging off somewhere or graphic displays laying on the desk are what I call sloppy. So, make it neat, make it compact, bling it on.

With the gold PLA, I decided the easiest way to differentiate it from my other Slic3r/Firmware settings was to “name” it, therefore it became “Midas”. It printed it’s own name as a matter of fact.

Kossel Midas

A HUGE advantage of building a second one is that you know where the weak areas are. And you pay attention to them to make damn sure you get it right the first time. The first stumbling block is getting the basic PLA parts printed accurately to start with. I printed these on my own printer and although I admit it’s not 100% accurate, it’s within .07mm dimensionally.

As I was building Midas I never looked at a build manual. I just put together the way it made sense to me that it should be assembled. As in logical. A much more enjoyable build. Besides I’ve had mine apart and together so many times that was just easier knowing what part had to be installed before some other part.

Secondly because of my own and others input, this kit has been upgraded in a number of key areas. Let me point out that those areas are extremely critical. Take the bottom frame corners. Taller and more robust. Take the extruder, extremely efficient compared to the original one. The carriage holders for the Traxxas rods, fabulous. Plus more.

In the process of building the Midas I paid attention to the areas where any inaccuracy is going to come back and bite you in the butt later on. Like the Traxxas rods. I have a custom jig that I made that does nothing more than make sure the Traxxas rods are equal in length to each other. Each rod is a perfect 301.92mm.

Why is this important? Those rods hold the effector, that’s the plate the hot end hangs from like a bunch of grapes and ensures that one rod isn’t stressing another rod. You want that effector plate to glide around like the marker on an Ouija board.

The hot end should fit snugly in the effector plate and you shouldn’t be able to rotate the hot end once it’s clamped in.

The bed rests, where the aluminum plate and Borosilicate glass sit, should be sitting flat on the 2020 beam. Peak underneath to make sure that things are sitting level on those pads.

Getting away from assembly for a second, let me talk about tools. Yeah. If all you own is a flat bladed screw driver, forget building one of these. Or plan on a number of evenings at a maker space where they do have the tools.

And what will you need? Metric hex wrenches, normal and ball end (2 & 3mm), long ones too! Metric tap for some of the fittings, metric drill bits (1.5mm through to 5mm), DVM (digital voltmeter), alligator lead, jeweller screw driver, soldering iron, 63/37 leaded solder (cause it’s better than unleaded in my opinion), crimper for the Dupont connectors, wire strippers/cutters, extra wire (16 gauge) and good lighting so you can see what you’re doing.

Interestingly enough, in spite of the fact that Canada went metric in the mid-1970’s, you’ll find it next to impossible to buy metric drill bit sets. Instead they sell the non-metric sets. You can buy taps and dies in metric. If you need those things, eBay or a maker space are your best options.

Back into the assembly portion, one of the most common displays that comes with the 3D kits is termed the “Full Graphic Display”. Essentially a 12864 graphic monotone LCD with a daughter board to connect to the Arduino MEGA 2560. They refer to this as a “smart controller”, all evidence to the contrary.

With this graphic display, you can’t just write at some point on the display and update that specific area. Nope. You have to refresh the whole display each time. So you’re writing a lot of pixels out. Of course it doesn’t look like that’s what you’re doing because in the background that’s what the u8glib Arduino library is doing for you. And it only goes so fast.

Herein lies the underpinnings of the rub. The computer is sending GCODE, the Arduino is figuring out where in space it has to go and extrude something, then it has to update the display so you know it did it. Now to be honest I have no idea why it updates the X and Y positions. They don’t mean squat to me, the Z is the only one I’m interested in.

To continue, we need to spin the graphic fan icon of course. Which is pretty much useless because there’s no feedback loop from the fan to the controller to even tell you have the fan connected. Hence, “smart controller”, yeah, not so much.

When the printer gets to a tight area, specifically a bunch of tight curves, it stalls. There’s just so much that the little Arduino MEGA can do, so, rather than just skip the display, it stutters the hot end for you. Yeah. Handy as heck.

This is why the rage a while back was to add a SmoothieBoard or some heavy weight processing power to keep it munching through the data. Which of course, introduced a number of its own problems. No such thing as a free lunch.

To remedy this problem there are three avenues open.

One, toss the full graphic “smart” controller and put in a non-graphic controller like the 2004 LCD.

800px Smart Adapter 9

The second, although not quite as foolproof, print from an SD card. Even then it can stall slightly on tight curves.

The third is to modify the firmware. Look for the XYZJerk values, normally set at 20 or so and drop them down to 5 or slightly less. If you drop them to 1, you WILL solve the problem, you will also entering a waiting game for a print or the completion of the next ice age. Yeah, it slows it down that much. The whole printer is spasticated.

In the case of both the 2004LCD and the 12864 “full graphics smart controller”, they are current pigs. if you’ve ever looked at one of these displays and notice it flickering, there’s a reason for it. And it’s like this…

To power the Arduino, that 360 watt 12V power supply feeds 12VDC to the Arduino Mega. On the MEGA is a 5V regulator that accepts the 12V coming in and drops it down to 5V so the MEGA and any attached devices can use it. The MEGA uses a modest bit of current, but when you tack on the display it goes up. The problem with getting the incoming 12V down to 5V is that anything above about 7Vdc is dissipated in heat. And the hotter these regulators get, the less efficient they become, until they overheat and go south.

The Arduino developers will tell you to run them with 9V DC adapters if you must and don’t advise using 12V. Seems the REPRAP PCB designers missed the boat on that one. No surprise, it’s open sore.

The instant you plug in a computer via USB the MEGA automatically switches from that 5V regulator to use the 5V coming in the USB bus. And the display stops flickering. So…want the MEGA to last a long time and only want to print from an SD card? Plug the Mega into a USB powered hub, use a 5V USB adapter (like you charge a phone with), or leave it plugged into a computer. Mine happens to be connected to my Astroprint box which is supplying the 5V to it.

The more you print and dive into the workings of 3D printers, the more you can see weak areas in them. You can spend a lot of time innovating little things that could be better.

I’d hazard a guess a lot of people jump into 3D and drop out of it just as fast when the problems rear their ugly heads. If you’re in that leaky boat, one oar, and a 200 foot waterfall dead ahead, check for a local makerspace. In general these folks will go out of their way to help you get running again, and probably educate you in the interim. Probably save your sanity….

My Kossel update….today @ 1143 hours of printing time total, my temp for the hotend was all over the place. I wiggled the thermistor wire and it came off in my hand. Seems all that shaking around on those little thermistor wires took its toll. Fortunately I had a spare so within the hour it was back printing. Hence, spare parts are a must…

13
Mar

3D PLA Finishing

If there’s a down side to 3D printing it’s the absence of colours. Basically the colour of the filament you have is the end colour of your print. True, that is some cases this works out fine. Like if you have white filament and you’re printing ghosts. Other times, not so much.

There’s been several attempts at solutions for this dilemma and they range from a custom multi-filament feeder Mosaic Palette to running filament through a felt tip marker to colour it. Course you just can’t change colours all that easy on the fly with it.

Appearing is a new extruder that has a single output but takes three feeds in. So tricolour if you will. My guess is that since the head looks like a plumb bob it’s going to have a fair bit of mass. Not something you want to swing around on the delta style printer.

So what’s some of the alternatives? Well, one is painting the end print. By hand or air brush. I tried this a while ago, sprayed a base coat of primer on a print and than hand painted it.

The paints I used were the typical Testers Acrylic’s model paint:

IMG 1238

Even with the under coating of the primer, you can see coverage is no exactly what I’d call great. Sure, you can say it’s got some “texture” but really coverage is minimal and depends on the primer colour.

IMG 1018

As stated I’ve tried the Dollar Store paint, Testers, Createx, and a number of others. Okay, but not great.

Back at the Dollar store the other day looking for some solar stuff to scavenge for parts, I happened across these…

IMG 1237

Same sized bottles as the Testers, but in scads of colours. Nail Polish. Like the wife uses. As I recall it’s pretty thick stuff and covers anything. So, I grabbed a few packs of the stuff (cause it’s dirt cheap).

First thing was, no base coat, just paint a sharkz head and see what it does. Single coat.

IMG 1239

You know, it actually covered pretty darn good. But what about trying to cover something on top of dark PLA…I used some gold glitter nail polish:

IMG 1240

Single coat and I wasn’t too careful about putting it on so I didn’t really try to fill in all the holes, just slathered it on. I’m thinking an additional one or more coats and it would be solid.

Then I went back and found my Minion. Repainted him with the colours from the nail polish…

IMG 1235

That’s two coats of nail polish colour. The light colours will not cover the dark coloured nail polish so keep that in mind. Nail polish always comes with a little brush and it works for the most part. If you need to get into small areas, you’ll end up using a custom brush size.

Put it on thick because it will shrink down thinner as the solvent in it evaporates.

The stuff dries reasonably fast…BUT, it stinks. You need GOOD ventilation or about about half an hour you’ll see nice little moire patterns in front of your eyes and be mumbling to yourself…ohh…look at the pretty butterfly…