Looks like you will need to create a second pin for your axle and poke it thru the side wall after slipping the bearing in place. Make sure you have good outside diameter clearance for the bearing so it can spin freely.
1 Like
Ok, I think that thanks to a colleague who looked over this thread, we have a solution!
He pointed out a thing that I had not really considered: feeding the TPU directly from the drier isnât a great idea. Nor is drying and then immediately using. The filament is so soft after even a small amount of heat that this will cause deformation and the aforementioned elongation of the filament.
So, back to the âbadâ spool of red TPU 95A HF. Used the default 12mm^3/s profile on the A1M and external spool holder. Only change I made in the slicer was arachne (all these prints have used it) and slowing the outer walls down to 50mm/s (I had forgotten this on previous prints, I donât think itâs the differentiating factor in the TPU problems).
Looks pretty good! Aside from some weird defects in the bow, this is the same filament that was causing all those problems. It seems the case that you really need to let the TPU cool down after drying, otherwise it simply wonât feed through the extruder in the way you expect. It seems that the X1Câs extruder was perhaps a bit more gentle and didnât result in stretching? Anyway, I now have TPU 95A HF working on the A1M 
1 Like
(if someone knows how I can mark this post as âsolvedâ Iâd appreciate a pointer!)
Interesting. But for me there is now another Question? Why didnât the automatic flow calibration work? I tought A1 Mini should detect less pressure and extrude more filament when the diameter of the filament becomes thinner.
Yeah that is a good question. I was getting prints that were really obviously a result of insufficient extrusion. I never once got any automatic detection of that taking place. So there is a mystery here about what the A1M is really doing in that regard.
1 Like
Do we need to dry unopened filaments? Or which filament types should be dried. Moreover, if we need to dry a filament at X1 C for 8 or 12 hours, the printer will be constantly busy with drying and we will wait for hours for printing.
I weigh and then dry all my new spools until they no longer lose weight. I prefer this to crossing my fingers and then having failed prints, because then I have to guess whether the failure is moisture related or something else, and then having to dry anyway.
All of my new spools have lost weight, some only one or two grams, some as much as eight grams (~8 milliliters of water). One or two grams of moisture in a kilogram of filament donât usually matter, six or eight grams will definitely cause problems.
When I tired of having the X1C busy with drying, I bought an Eibos dryer.
I came across this thread cuz I still have problems printing grey Bambu Tpu HF. I print on a A1 direct from a sunlu S2 dryer. I red hear that maybe the filament is to soft when printing direct from the dryer but in my case the bowden is 50cm, in my opinion enough to cool down.
Do you print with 0.8 nozzle?
I wonder why the printer dont catch the filament. But when I push the filament it came out easily. Gear is cleaned.
I also tried to reduce the pressure on the extruder gear. No Luck.
any suggestions?
If it helps, I had excellent results printing a non-BL filament of HF TPU95A using the BL TPU HF filament preset.
I used a stainless-steel 0.4 nozzle and a 0.2 layer height. I had excellent results at twice the speed of any other TPU I had used in the BL printers.
I had very poor results with the 0.4 hardened nozzle.
I used an A1 mini and an A1 (not a mini) for testing (I didnât have my P1S at the time. Both used the BL provided spool mounts.
1 Like
Hello everyone, i also tried the Bambu TPU 95A HF. iam Printing with a flowrate of 4 currently for testing and my parts have some points where it seems that the filament is not extruded for a short time, but i cant find a reason whyâŚ
someone else with a similar issue with TPU???
i dont know why but i cant upload a foto here 