Time-lapse 3D printer videos

I have two 3D printers and each has a webcam. I use Octopi (Octoprint on a Rasberry Pi) and can stop bad prints from my smartphone if I need to. Some materials are difficult to print and hours into it I can cancel the print job. I tried attaching the webcams to the printer’s heated bed so that I can get stable time-lapse 3D printer videos.

This didn’t go too well. I have both printers in Ikea Lack table enclosures and adding an arm to the bed meant that the camera would smack into the front door of the enclosure. When the bed moved back and forth the camera shook. This made for blurry videos. To address this, someone came up with software to pull it off with a stationary webcam. It’s called Octolapse and you can review the code on Github.

Software Plugins to the Rescue

My favorite software platforms can be extended by add-ons or plugins. Octoprint is no exception.

The Octolapse plugin waits for an event in the print job, moves the bed and extruder to a position you set and then snaps a frame. I use when the layer change for that event. After the frame is snapped the print job resumes. When the layer shift happens again it repeats and snaps another frame.

The results are fantastic. I turned off autofocus on the webcam to prevent some blurriness. Here’s a time-lapse of a multi-color snake I printed. It took 6 hours and 45 minutes. The video is 6 seconds long. It’s not a tall print so there’s not many layers to snap images.

The default Octopi time-lapse print is 1 minute and 37 seconds long and looks like this.

I have not tuned the Octopi video settings and the quality isn’t very good. The reason that the Octolapse version is better is because it’s not a moving image exactly. It’s a collection of sharp still photos stitched into a single video.

This is a better solution than a moving camera attached to the print bed. You can put the camera anywhere and obtain smooth, sharp, time-lapsed videos of your prints. I will probably put my webcams on a small stand and position it closer to the bed for larger full results.

It does add a little time to the print because the plugin inserts the commands to move the bed and extruder, snaps a photo, then goes back to printing. For each layer this is repeated. But the prints typically take hours to print and the time added is negligible.

This is a very elegant solution. The plugin has profiles for my Original Prusa i3 Mk2s MMU and one for my Monoprice Maker Select v2. I’ve not sorted out the Monoprice (the bed needs leveling and isn’t working too well right now) but once I have, I’ll post videos from that printer too.

Prusa MMU for the MK2s

I think I can call the multi-material upgrade of my Prusa Original i3 Mk2s a success. It took me about a day to put together and another day of tuning but I like the results and the prints look good.

Here's what you get with the upgrade kit.

  • A new E3D v6 with multi-material heat break
  • An additional daughter board to drive the extruder motors
  • All of the new plastic parts in ABS
  • Bondtech gears for the extruders
  • Bowden tubes
  • Spool holders for 4 rolls
  • All the fasteners needed

The instructions on Prusa's site are very good. I setup my laptop on the kitchen table, put the printer next to it and got to work. I took my time and spent 7 hours last Saturday just assembling it. A few quick tests and all was right in the world.

The Bowden tube setup is different and I need to get used to it. I had a clog on extruder 2 and had to  unscrew the Bowden tube from the print nozzle to clear it out.

I did have to butcher my Lack table enclosure. I run my printer in the basement and that gets cold. Enclosing the printer guarantees that I'll get better prints.

Less S3D, more Slic3r PE

The one thing I am not thrilled with is the software. I use Simplify3D a lot because I generally get better results. S3D's supports are magical and just pop off. In the past I would use Slic3r PE only when I needed to.

S3D does not yet support the Prusa MMU. There is a single color profile that I found on the Internet and that works well. But for multi-color prints it's Slic3r PE or nothing. This isn't too bad for me because once the bed is level and the z height is adjusted (-0.867 mm on mine, I set the PINDA probe a little higher) I get good first layers.

The default printer profiles generally work. The only adjustment I make is to set the first layer speed to 20 mm/s. After that it's full speed ahead.

The Purge Block

If you look at the image with this post, you'll see that each multi-material print has a block next to it. When the printer changes filament the head moves to the block and prints a 60 mm by 10 mm layer. By the end of that the nozzle is primed and the color can be applied.

That layer of block either gets completely filled in or if there's not filament change a small infill is applied for the next layer. Here's a closer look at the 2 color Moai.

That print has 2 filaments on every layer. That purge block is solid at 60 mm x 10 mm x 60 mm. I don't really think that's wasteful as it keeps the results clean. I may play with those settings to reduce the size.

Here's the fun thing: if I printed 1 or I printed 10 on the same job then the purge block is still the same size. It has to be the same height as the print itself because the print nozzle cannot descend. That would risk hitting something else on the print bed. Next time I'll print more than one and lay it on it's back. That should reduce the purge block and get more use out of the filaments.

Where to Get Objects to Print?

You can make them yourself but Thingiverse is loaded with many good models. There's more than a few that my kids already want me to print. It will be a while before I really make my own.

In the meanwhile I have a printer that can do up to 4 different materials in one go. That's cool and I'm having fun with this hobby.

A 3D Printed Dial

I had a broken dial. I also have a 3D printer, so rather than epoxy the heck out of the old one, I designed and printed a replacement. One finished 3D printed part was produced with just a few hours of work.

My pool has a salt cell that uses electrolysis to convert salt in the water into chlorine. You manually set the level from 10% to 100% generation but I usually leave it alone at it’s maximum setting.

That dial literally has one job and it broke. It was flush with the panel so rotating it meant scrolling the right exposed side. Built out of cheap injected plastic though it did last for 7 years.

In Fusion 360 I started with a stub to make sure I sized the knob holder correctly and ended up with a knurled dial that protrudes from the machine. My process isn’t very good and I learn through “what’s that feature do?” For example, the knurling was put on my making a sketch, extruding and cutting it out of the dial then creating a circular pattern out of that 120 times.

The effect came out great. My first pass has knurling that was too shallow (0.5 mm). Until I printed it out I couldn’t see that I had made a mistake. Once I saw it I went in the designs time line, deleted the sketch (which also deleted the pattern) and re-did it again. The new knurling rocks.

The last iteration was missing something. I put on the face a cutout to show that turning it clockwise means more, counter clockwise means less. The original dial had that printed on the face but my cutout is more prominent. It also meant I got to try something cool on my design.

I started with PLA but when I got what I wanted I printed it in ABS plastic. Here’s a photo of the iterations.

Yes, I could have fixed the old dial with some epoxy. That would have molded the broken part nicely. But it’s not often I get to use one of my toys in a real world way like this. 2 days of on/off fiddling got me the part I really wanted.

3D Printing the WordPress logo in two colors

My 3D printer only supports having one filament loaded at a time and that generally means the objects I print is one color. I wanted the WordPress logo (naturally) and two colors would be cool. I can print pieces in different plastics and assemble them but sometimes you want one piece. Good news! My printer’s open source firmware supports changing filaments before the print job is done. That let’s me start the base in one color but switch to another before the print is completed. Here’s how I did it.

I downloaded the WordPress logo to my PC via Wikimedia in SVG format. SVG is a vector format for images that can be scaled without losing sharpness. I loaded that into Fusion 360 and deleted the text to the right and just kept the round logo.

In Fusion 360 I scaled the logo to 50 mm diameter. I then extruded the white portions in the logo to 3 mm. The circle outline and the space between the parts of the “W” were extruded to 1.5 mm. I exported that to an STL file and loaded it into Simplify 3D. This is where it gets clunky.

For slicing 3D prints into a format the printer can understand I use software named Simplify 3D. It’s not opensource (or cheap) but it’s very extendable and saves me a lot of time.

Simplify 3D supports scripts that use regular expressions to locate text in the generated G-Code output file and make substitutions. In the generated code it also comments each layer of the print so there’s a “layer 8” text where I want to insert printer commands to swap filaments.

Figuring that I needed to modify layer 8 was a pain. There’s probably a well documented way to do it but I sent my G-Code output file to Octopi. I loaded the file but did not actually print it yet.

OctoPi comes with a built in G-Code viewer. I moved the slider up until I found that layer 8 was where I wanted the change filament commands inserted.

I then deleted that file from the OctoPi, went back to Simplify 3D and in the process settings I went to Scripts -> Starting Script and added this to the “Additional terminal commands for post processing” field.

{REPLACE "\n; layer 8, Z = " "; layer 8\nG28 Y0 X0\nM300 S0 P1000\nM25\nG92 E0\nG28 Y0 X0\n; layer 8 "}

And generated and updated G-Code file with additional commands that I sent to Octopi. I loaded up a spool of blue filament and began printing. Midway through the print the extruder moved to the home position (but did not change it’s height) and waited for me to change the filament. Once I did that I loaded Octopi’s web page on my phone, logged in and clicked “Resume”.

The resulting prints came out well and I repeated the process with the white filament first. The bottom is one color and the top is another at just the right place.

This hardly took me anytime at all. It’s not a fauxgo, it’s a legitimate SVG (well, I hope it is) representation of the WordPress logo. The blue is a bit off but I can be forgiven for that. The PLA material is listed as “Egyptian Blue” and it’s the closest I had on hand.

There’s probably an easier way to get the layer accurately without using Octopi but it works. If I find an easier way then I’ll update this post.

What I really want to do is print the badges for the WordPress teams such as Support, Docs, training, etc. That’d be cool and I may do that this weekend.

This all came about because my brother got his 3D printer working in two colors on the same layer. His printer has two extruders and can print one color next to the other on the same layer. My printer does not do that but I’ll catch up. Competition is good. 😉