Hello! I just recently upgraded my P1S with the abrasive filament upgrade. I have printed several prints in PLA, PETG, PETG-CF with it, but for some reason TPU will not print, it will not extrude out of the nozzle at all. What could be the cause? How could I fix this?
2 things.
Make extra sure it’s dry. 2nd use a .6 nozzle, will come out better. You can use the .4 but make sure it is dry.
The filament is dry, and I have used the exact same TPU dried just before the upgrade. Thank You for the help!
Can you confirm you are using the external inlet and not a slot in an AMS.
If you are using the AMS it will not work unless:
- You know how to make it work, you clearly don’t, most don’t
- The TPU is specifically TPU for AMS or anything more rigid than TPU 95A
Nope, no AMS, just using the external spool holder.
It’s tpu. When you think it’s dried, dry it some more. My 2 cents.
edit: No idea why I replied to you Malc
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I am running PEBA 90A through the external inlet without issue. This is softer that the most commON TPU 95A.
You maybe getting stuck at the first hurdle, namely; loading, it is more time consuming than indicated.
- Make sure you have a spool holder that is easy to spin when the TPU is on it, any friction will cause problems
- Make sure you have PTFE tube from the spool holder into the external inlet
- Tell Bambu Studio (or Bambu Handy) that the external spool has TPU 95A
- Tell the printer to begin the loading process
- Start pushing the TPU into the PTFE tube while the hot end heats up
- You should achieve this before it is at the correct temp has been reached
- Make sure you apply pressure on the TPU so it is being gently forced into the nozzle
- The screen will ask if you have loaded the filament, tell it to retry
- Repeat the step above 5 times as the time it gives isn’t far to short for the needs of TPU (when you are experienced you can use a lower figure)
- Gently pull on the TPU, it should not easily come out, if it does repeat the previous two steps
- If you have tension, say it has loaded
Print a test cube (or anything really simple) to test your first time worked.
If successful, print like an nutter.
I am that great.
Filaments can arrive damp, do not assume new and sealed means dry.
Those are two great pieces of advice, but be aware the advice isn’t always required. Maybe I am lucky (or just brilliant), but despite owning two filament driers with the ability to dry 5 spools at the same time, I have never needed to.
I take care to zip lock up out of use filaments and store the, correctly and much of my filaments are in AMS units, expect for TPU and PEBA as they must be attached externally. I have never dried them either.
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Maybe…lol
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Ok, I did the steps above and got another spool of TPU. Printing it now. My worry is that it was printing TPU just fine right before the upgrade, and now after the upgrade it will not print it. Could the idler tensioner not be tight or loose enough?
Well stock no. If you didn’t tighten it back to where it was maybe. I’ve never had to mess with mine, however I always put it bac where it originally was. If it’s not feeding then loosen or tighten depending on what it needs. You can feed some filament and see if it comes out.
By upgrade I assume you mean Hardened nozzle and extruder gear. If you bought a High Flow nozzle then a .4 can struggle with TPU.
Don’t assume a new roll is dry. Most often they’re not as dry as we would think.
Little story.
I once purchased some Siraya Tech 95A TPU. I’d been printing anything and everything without an issues. This stuff wasn’t having it. I’d get nothing out and so I contacted Siraya Tech for some advice. Their advice, dry it. Then when you think it’s dry, dry it some more. So I did.
Suddenly it was extruding and printing very well. Printed better with a .6 but it was printing.
So, that’s why I’m giving you that advice. I’ve used it with TPU since and never an issue.
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The tensioner screw should be tightened until it stops turning. That is the original position, where the spring provides the correct pressure. Looser is too loose; tighter does not increase the tension.
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Ah ok, I did not know that. Will check if in right position.
Update: I was able to get it printing but it was a bit under extruded and stringy, even when it was dry. Will dry again.
Are you sure the nozzle does not have a partial clog? You might want to do a cold pull with some PLA to make sure it is clear.
Brand new nozzle. Did some cold pulls just to be safe. After the TPU failed, I printed with PLA no issues.
I’m in the exact same spot.
Printed TPU 95A many times, then upgraded to hardened gear set straight from Bambu and the filament won’t load.
I can get the gears to grab it, but after pulling it in a little, the fears start to click and it won’t go any further no matter what.
Finally gave up and I’m printing some PETG now just fine.
I’ve tried all the advice in this thread. None has worked. My next step will be to switch the gear set back and see if I’m able to print TPU again. I have to say, of that fixes it, I’m not going to be happy. It is not ok to make people switch extruder gear sets back and forth for TPU, that’s just insane.
Good Luck! I tried all of the advice too. After about 2 days of trying, I got it to print an ok TPU roller. Try increasing the idler screw, if that does not work loosen it. At this point I am stuck too. I can get the gears to grab it too, but not to extrude it. If you need to use the regular gears for TPU, I guess I will be using my Prusa for TPU only, (the Prusa is getting old, and it shows in the print.)
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Thank you! It’s as we feared though. Has nothing to do with a hardened steel nozzle (I figured, but I replaced the SS nozzle and gears at the same time), and nothing to do with needing 5 loading tries or any other nonsense.
Looking at the SS and HS gears next to each other, the SS look to my eye to have more bite to them, more defined edges, than the HS.
Either way, now I need to decide if I wanna grab a cheap Creality or something to print TPU with or what. With the restriction of only one user being able to be logged in at once and now this, I’m hesitant to give Bambu much more money.
I suppose I could buy a second extruder set with the SS gears and do full extruder swaps on the P1S, which would be easier and quicker than gear swaps, but still… fully ridiculous that they can’t give the HS gears enough bite to grip TPU.
Poor form Bambu, poor form.
I just printed some Bambu TPU 95A HF yesterday on my P1S with a hardened 0.4 nozzle and extruder. I have a side mount spool holder and fed the filament through the PTFE tube like normal. There must be something in the filament path causing a blockage/restriction.
Do you want to submit a form to Bambu Lab stating the issue? If you do, I will do the same. Maybe they will fix the issue or give tips. Replacing the extruder every time for TPU is nuts, I probably will not do that.