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Archive for December, 2016


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.


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…


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.


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.


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.


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…