Printing TPU on an Ender 3 V2 (Bowden tube) HELP!

Just got at Christmas my first 3D printer. Went with an Ender 3 V2 and am so happy with it as a supplement to my dear Primo.
I have in my basement but on the finished side as my workshop is pretty tight already. I was looking for some good projects and found @Rloschy such great design and made it. He was generous
enough to share the files even though it turns out it fits the Makita straight away.

The bristle skirt is printed in TPU and pressed into the groove. You can print various lengths to see what works best.

I tried yesterday the TPU and it was a mess. Lots of conflicting advice on the Internet but thought I ask the best group of experts I know…you guys…!

I do not want to change my Bowden stock Ender 3 to a direct drive yet but would like to figure it out how to do it with the basic stock machine.

As always thanks to you all.

Flexibles through a bowden generally don’t work very well. It’s like trying to push a wet noodle though a crazy straw.

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Hi Barry…
I totally agree but wanted to try to learn a lot more before starting conversions. Just being conservative, as sometimes in the past I can kind of chase the golden ring. I did do some great software upgrades to the Ender display that was a no brainer and will I’m sure get but at this point my first barrier is getting the basics down.

Actually just got a test print done with with the TPU this morning so maybe some progress…

The softer tpus are just begging for trouble, but the stiffer ones aren’t bad.

I don’t recall which extruder version comes on the v2, but my V1 had a lot of open space between the gear and the hole it had to go through. If you have that, too, either upgrade or it fishmouth some ptfe so the filament can’t squish out sideways there.

Beyond that, just go slow and turn the retraction way down. If you have a lot of problems with stringing, maybe faster travel moves and accelerations can help break them, or try cooler temps. I think I was 5C under the recommended settings, but I never checked if that was an accurate temperature. (maybe when i set 190 it was really giving 195 at the nozzle).

Good luck!

A stock Ender 3 and TPU is going to be a challenge. Even if it you got it going you’d have to watch it like a hawk as it could jam at any time.

About the only way I could get my Ender 3 to print TPU consistently was to install a SeeMeCNC EZR extruder. Switching out the stock bowden tube with a Capricorn replacement helps too. Up to you if that would make financial sense given you may not print TPU very often.

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I will say that my capricorn tube lasted longer than the white one ender sent. Forgot all about it, but highly recommend at the first replacement.

The Capricorn tube has some kind of additives in the plastic that self lubricate. Noticeably more slick to the touch and creates much less friction for the filament to travel to the hotend. A very cheap and easy upgrade to help with TPU.

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Interesting, I thought it was just purer ptfe and better tolerances.

I have been able to run ninja flex through my Ender 3. I forget the exact numbers but ninja flex is like 5 to 10 softer than most TPUs. Here is what I did.

I replaced the stock drive gear with this.

I did switch to a blue Capricorn Bowden tube.

I still use the stock hot end extruder.

I swapped out the build plate with. PEI Powder coated steel sheet. TPU releases much easier from this. But there are other ways around having TPU stay stuck to the stock build platform. this upgrade was mostly for printing PETG but it helped with TPU as well. The stock is the best option for PLA.

I use Prusa Slicer standard TPU settings. But I make sure I only print one item at a time so it doesn’t have to retract and start again all the time. So looking at your dust shoe I worry that it may have to retract and lift at the end of each end of the combs. That would be difficult. Once you get TPU going with a Bowden setup you don’t want to stop it.