Mystery of the 0.20mm (revisited)
Prusa Mini, PETG, and Errors in Small Pieces
The Prusa Mini, at least in PETG, will experience some sort of thermal expansion/error with small pieces < 20mm in height. That’s the only conclusion that make sense. Adjust the prints and don’t expect fidelity of that accuracy on smaller parts. That means adjusting cylinder heights, widths and include bolt holes in designs.
What I Didn’t Try (yet) with Prusa Mini, PETG and Reducing Error
I have some plans to repeat my experiments on a PEI smooth sheet with no heated bed. I just haven’t decided if I should start with glue stick/windex first or just going “all in” and printing straight on the PEI.
With a textured sheet, PET refused to stick to the build plate so a non-heated bed was not an option. 50-60c seems the absolute minimum to keep a PETG print from detaching from a textured sheet.
My Experience with Prusa Support and PETG Errors
Not the best. I’d say 3 outa 5.
L1 tech support warned me any changes to GCode could void warranty. I clearly explained that the gcode modifications was to adjust for the XYZ stepper calibration. I even told the support tech the code I used. I understand why this is a common response from L1 but really does disservice to the DIY spirit of 3D printing. The thought that you can just get a printer, out of the box, with any filament, and can get “perfect” prints is BS. It takes time, effort, troubleshooting, etc to get the desired output.
Support just dropped off in silence. I eventually got pushed to L2 or L3 support but there was no answer of “hey, we tried your experiment and verified this is specific to the Mini.” Despite some better technical support on what to try, the L2 just decided my case wasn’t worth it.
What Should’ve Happened
I’m a realist. If this is normal, then it’s normal. If it’s not normal, I’d like to figure out how to make it work or understand why. I didn’t get an answer to either.
The role of supporting a product is to clearly list it’s limitations and why to a customer. 3d printing is still very DIY. I’m not upset I have the drift. It was just bothering me I couldn’t figure out why. The why is more important.
Don’t sell me babble that makes no sense. I’m not an idiot so don’t assume you have to handwave with “voiding warranties”, don’t use gcode, don’t troubleshoot your printer etc. Definitely don’t tell me things about FDM that are patently false and should have no bearing to the issue at hand. It’s really annoying the first response from L1 is to “reboot your PC” or say that the error is Z-Axis offset when I clearly said it only happens < 20mm and disappears after 30mm.
PETG Errors on the Prusa Mini, a Conclusion
I still like this printer. It’s a good product. I just wish support was more transparent about it’s limitations, more engaged to technically reproduce and troubleshoot issues, etc. Just showing that they care about the customer would’ve been nice. There’s no need to gaslight your customers.
