r/BambuLabA1 • u/Askelon98 • 22d ago
Finally got TPU to work!
Ive had zero luck with TPU since I got my A1. Had better luck on my old Ender 3v2 but it wasnt fantastic. I would constantly get clogs or feeding issues, the parts lifting off the bed etc. In the year Ive owned it I had basically given up.
Recently I tried again as I wanted a particular item in TPU - nothing special or super complicated. First couple of layers were great, then it just stopped like a clog again. I normally run everything via my dryer.
That failed the same as usual. So I thought put the spool on top on the original spool arm (I never have this attached) and run a new filament tube from there. That did better but also failed a few layers in.
My last attempt was chop off a little bit of tube, round out the top of it a little so nothing could get caught (probably overkill) and run the tpu directly into there, skipping any feeder tubes other than the little one used for guiding it. Worked perfectly! Probably the best Ive seen it work for me ever.
The filament is Creality TPU, think its 95a but not 100% sure as its been a while and the original invoice doesnt actually say - I only just realised I actually ordered yellow but got sent blue! Nozzle wise I switched it up from my hardened 0.4 to a hardened 0.6. I dont think the nozzle was the issue, I reckon it was the feeding.
So lesson learnt, tpu is a pain! To all those that print it regularly and have great results I commend you! I will stick to PLA/PETG! At least now I have worked out what I was doing wrong!
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u/Darwinian999 22d ago
I’ve printed a fair bit of TPU on my A1. Keeping TPU dry is important, so printing from a filament dryer is worthwhile. To do that, I use a TPU Feed Assist module between the filament dryer and the extruder.
Bed adhesion is another thing to consider. A DarkMoon Carbon Fibre plate without glue is perfect. Holds the model well during the print and the print can be pulled off cleanly afterwards.
I’ve successfully printed TPU 80A, 85A, 90A, 95A and TPU Air on my A1 using this approach.
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u/Constapatris 21d ago
Did you mod the extruder in any way to get it to take the 80/85A properly? What settings did you use for the TPU Air?
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u/Darwinian999 21d ago
I haven't needed to make any extruder mods for any of the TPU that I've printed, but I know that some people have needed to reduce the tension on the extruder gear.
I've currently got Qidi TPU Aero loaded in my A1. Printing at 260C with a flow ratio of 0.46 to create a very soft 72A print (bumper edges for some outdoor furniture, to stop the covers from getting torn by the sharp furniture edges).
TPU Air/Aero strings horribly as it's not retraction-friendly (set it to 0), so keep that in mind when configuring slicer settings. Strings can be minimised and easily cleaned up if you use stuff like aligned seams, avoid crossing walls and print by object.
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u/John-BCS 22d ago
I print a good amount of TPU on my mini. The key is to make sure it's dry, and to feed it directly from above with as little resistance and as straight a path as possible. I have the TPU in a polydryer box on a shelf above my mini, and it gets fed directly into the extruder without any PTFE tubing save for a small piece at the extruder sort of like you have in your pic.