Can't print TPU as the extruder is clogging/jamming

Can't print TPU as the extruder is clogging/jamming  

Eminent Member

I have a FlashForge Creator Pro that works great, TPU does just fine. I tried TPU in my relatively new i3 MK3 and for whatever reason the TPU is not extruding reliably. It seems like the extruder is over flexing it when feeding it or something?

Any suggestions on how to succeed with TPU with the i3 MK3?

Neal C
Richmond, VA...
Posted : 09/01/2019 9:07 pm
Trusted Member

Any suggestions on how to succeed with TPU with the i3 MK3?

I have had really good success printing TPU with some slightly modified Extruder parts - unfortunately it turns out that the printed part filament path doesn't perfectly line up with the motor/bondtech gears in the current R3/B7 (and prior R2/B6) parts.

With my modified parts, the only jam or issue I had was while loading the TPU filament via the "Load Filament" option on the front panel menu (which really tries to load too fast for TPU already - it's better to manually slowly feed it in via the move E-Axis menu option).

See github here for a full discussion of this issue, and pictures demonstrating the curve in the filament path that causes issues with TPU/flexibles:

I've posted my parts and further descriptions in the User Mods section of this forum:

Here's a direct link to the parts:

MyMiniFactory (Functional Parts and Mods):
Thingiverse (Fun Designs and Remixes):
Twitter: @USCbutterworth
Posted : 09/01/2019 9:37 pm
New Member

Check the extrusion multiplier in filament settings. I can only get flex materials to print with a multiplier of 1.

Posted : 10/01/2019 5:34 am
Estimable Member

Folks having problems printing flexible filaments might want to have a look at this gadget I just posted on Thingiverse: It's a little tricky to install and adjust, but it's working well for me. YMMV.

1. "Creativity is the sudden cessation of stupidity." and "Any problem can be solved with the materials in the room." -Edwin Land, inventor of the Polaroid Land Camera. 2. "If I can't fix it, it isn't broken." -Me....
Posted : 17/01/2019 6:39 am
Active Member

On my Mk3 I was able to print TPE by removing all retraction and slowing down to 15mm/s. Once I did that I was able to print the tires for my 3DLabPrint QTrainer.

Posted : 19/01/2019 4:25 am
Noble Member

1. Release the pressure from the bondtech gears
2. Increase the nozzle temp if you encounter issues (235C is just perfect)
3. Print with constant speed 10-20mm/s (15-20 work best for me)
4. No retractions

It's very important to set constant speed for everything and verify that in the preview.

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Posted : 19/01/2019 4:42 am
New Member


Thanks guys.

I was unable to print one single tire for plane from 3DLabPrint QTrainer unless I did the steps proposed by Nikolay.

I will experiment also with 240°C and higher speed, say 25/35. Alternativelly 235°C and no retractions. The goal will be to achieve higher speeds since printing with 15 mm/s is pretty slow :-).



Posted : 15/10/2019 3:09 pm
Active Member



how do you set a constant print speed for everything?

Posted : 18/08/2020 5:45 pm

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