(Not really voxel related)
Restoring a Thingomatic:
TLDR:
Install the Sailfish firmware (and use Mac or Linux to do this if possible.)
Respect recommended hot end temperatures (printing PLA at 220 C will likely clog your printer within 30 minutes of printing. Hot end at 206 C worked for me).
Turn off ‘Temperature override’ in the Sailfish firmware so that Sailfish will respect temperature commands in your gcode.
Edit the skeinforge profile for the Thingomatic (using the Sailfish ReplicatorG slicer program) so that it generates gcode to set the temperatures you want. You can also set a base layer speed multiplier to make your print head move more slowly while it prints the base layer–this seems to help in getting the base layer to stick. (TODO: document where to find them which skeinforge settings.)
Long drawn out version:
In 2017, I was loaned a Thingomatic with a heated build plate (HBP) and an MK7 extruder. This is my attempt to document the process by which I got it working.
Hardware:
There were no hardware components that needed to be replaced. I did try replacing the extruder with an upgrade that was meant for a MakerBot in an attempt to solve extrusion issues that I was having; this was a bad idea and actually made things worse. (More on this a little later.)
Actually, I did replace one screw. The extruder came to me missing one of the screws that holds it together; there are two screws that bind the fan, heat sink, extruder plastic parts (the mechanism that pinches the PLA/ABS against the stepper motor coupler–not sure what to call them), and stepper motor to each other. If anyone ever needs this–hopefully not–the part is a:
M3 40mm hex screw
I didn’t have and didn’t replace the plastic stands that normally sit between the fan and heat sink and have, so far, gotten away without them.
Software/Firmware:
I failed to print anything on the Thingomatic using vanilla ReplicatorG software and the original firmware. I forget what I tried or what seemed to fail. I think that I got the machine to start making a failed print using an older version of RepG. I never got the Thingomatic firmware to read an SD card. All (failed) prints were done over USB.
In any case, I decided to install the Sailfish firmware.
Trickiness with installing new firmware:
Step one is to download the Sailfish version of ReplicatorG. Then use it to install the Sailfish firmware.
I failed many times to install the firmware. And never succeeded using Windows. (Apparently, using Windows is even harder than Linux/Mac). Installing from a MacBook worked after a handfull of tries.
You have to hit the reset button on the board right before you hit the ‘install’ button in the Sailfish-RepG GUI. When the install worked, I hit the two buttons nearly simultaneously. Unfortunately this took a while because RepG-Sailfish takes a long time to decide that the install process has timed out and completely locks out the user while it does this and there’s no feedback to indicate whether you’re watching a stalled out attempt or impending success.
Sailfish:
Sailfish provides granular control over printer settings and this turned out to be key in diagnosing my print problems.
Calibration:
When running a Thing-O-matic using Sailfish, you have to run the calibration script to tell Sailfish the printer’s X/Y/Z dimensions.
What the first step is not:
To calibrate, the first step is not to go to the ‘Calibrate’ menu from the main firmware menu.
The first step is to use the ‘Jog’ menu to move the tip of the hot end very close to the platform in the Z direction and right in the center of the platform in the X and Y directions. (‘Very close in the Z direction’ means that the tip of the hot end and the platform can pinch a piece of paper such that the paper can move but with a slight drag.)
Then exit the jog menu and use the calibrate menu.
Extrusion trouble:
Once the machine was calibrated, I could again return to making failed prints (yay!). This was actually progress since, now, I was just getting extrusion failure rather than murky, undefined failure.
The extruder was under extruding and then just not extruding.
This is when I tried replacing the extruder. The replacement parts were for a later model MakerBot and were too thick to accommodate the heat sink and fan. But I decided to try printing without the heatsink and fan and with the upgrade.
This made the under extrusion a lot worse but, as a silver lining, prompted me to notice the source of the problem.
The source of the problem was that with each print, after a few layers, a gob of PLA would form around the hole that led to the hot end. Luckily I caught this and stopped prints relatively quickly and avoided flooding the entire mechanism with melted PLA.
After some misguided attempts to more perfectly center the extruder over the hole, I read that the problem was caused by setting the hot end too hot for PLA.
At 220 C (normal for ABS), PLA filament will melt prematurely–i.e. an inch or so above the hot end itself–and, thus, tend to buckle as it approaches the hot end. Not having the fan and heat sink obviously created even more of a risk of buckling.
So the solution was to set the hot end temperature to 206C. (Some people suggest going as low as 196C but 206C worked for me.) And to replace the original extruder hardware.
Minor nuissances: at first, I couldn’t get the firmware to obey the gcode instructions that set the hot end temperature. I was having to set the temperature in Sailfish’s ‘print in progress’ adjustments menu. It turns out that I needed to turn off “Temperature Override” in the Build Settings menu.
Last problem:
The PLA was not sticking to the build plate very well. The printer had a heated build plate that was set by the firmware to 90 C. PLA has a better chance of sticking to build plates at 60 C. (Although if you’re lucky enough to have your print stick at 90 C it slides off effortlessly after it’s done.)
[Edit: Actually, 60 C isn’t much better than 90 C; the prints fail to stick almost as readily. I’m now printing at 40 C and using painter’s tape. I can’t guarantee that this is the ideal way to go but my latest print stuck and then popped right off when it was done. ]
Unlike with the hot end, there’s no print in progress adjustment for the build plate temperature, so I was just ‘winging it’ at 90 C while diving into the Skeinforge profile in ReplicatorG and thinking I was missing a setting.
But the solution was to turn off “Temperature Override” in this case too.
I forget whether I ever, in fact, found the correct skeinforge profile setting. I’ve just been making sure I’ve got the right hot end and HBP temperatures by looking at the top part of the generated gcode.
Related tip:
Printing the first few layers at a slower speed is probably a good idea, especially if you’re foregoing painter’s tape and using PLA as I am. Skeinforge profiles provide a first layer print multiplier setting.
Skeinforge lingo:
Feed rate: how fast the print head moves.
Flow rate: how fast the plastic gets pushed by the extruder.
Travel feed rate: feed rate while not extruding
Skeinforge profile settings that I can remember tweaking:
These are mostly guesswork on my part–not in any way authoritative. Consider these to be at best a starting point for your settings.
The Skeinforge profile editing GUI is pretty hard to navigate. These settings are just what I can remember changing.
Speed:
–Feed Rate: 30 mm/s (default)
–Flow Rate Setting: 80 (default?)
Object First Layer:
–Both feed rate multipliers: 0.5
–Both flow rate multipliers: 0.9