So I’ve been using that perfect bridges TPU profile and used gpt to convert it to a creality k2 plus compatible version. It seems like no matter what I try to tune the bottom layers of my tpu prints are a bit brutal. The walls always bow up and the nozzle tends to extrude outside the perimeter due to the bowing. What could be wrong here? I’m new to tpu so just trying to dial this in any way I can.
I will say the creality hp-tpu works GREAT but any other tpu I’ve tried has this bowing.
Try slowing it down (on the printer itself) to 50% speed.
idk why I created a new thread when this is already the topic of another one 
but yea next one I do I’ll try 50% on the bottom set of layers then speed back up to 100 after the bad zone is done. So far it’s typically been the first 1.5-2cm of a print
In your filament profile, see what mm³ is set. TPU can vary widely on what it can handle depending on brand. Some need as little as 3 where some can go 12 or more. So if your profile is set to high that can cause this for sure.
I have it set to 2, which is where I was able to dial this particular brand up to without being a complete disaster
Out of curiosity, what brand of TPU are you using?
Thats the bottom of the handle part right? Yeah you have to paint supports up a little higher for that to come out any good. That fillet on the bottom is too much for a TPU print without supports.
When you run out of that filament, give this one a try. Its worked well for me. Geeetech TPU
I have some geetech as well but was having some issues with it after I swapped to diamondback nozzles. I’ll throw that roll back into the dryer and see what I can do with that next.
Honestly there’s a lot here to like. The round walls look consistent, and the corners look sharp and clean. TPU is just tough to cool. Overhangs always struggle with cooling. My guess is you need more cooling, or to go slower. That could explain why the both the bottom transition up is rough, as well as that slope in the back that’s sticking up.
I’m printing Overture’s regular TPU also. Overall it’s performing well, but I’m having blobs. Still narrowing down whether it’s a temperature issue or PA issue.
Make sure you have “avoid crossing walls” turned on. That has helped a lot of people with the blob issues on the outside of the prints.
can confirm. that plus painting specific seam spots so the inevitable blobs around the seam is easily removed and the remaining roughness isn’t seen or felt by the child.
Thank you! I could have sworn I had this on, but sure enough, it’s unchecked for my TPU profile. I recently switched from SuperSlicer to PrusaSlicer, so I had to rebuild a lot of my profiles by hand, and this must have gotten overlooked. I’ll try this for the next piece.
No worries! I have noticed in Bambu, you have to be on Global to get the option for it. It doesn’t show up in “objects”. Only mentioning incase someone comes along reading later and can’t find it 
I’m using the same one (for the straps. Same one in purple for the handle/tires) and I’ve had some issues too. I was able to get all the parts completed though, and everything turned out really well except the handle grip which is pretty ugly and kinda cracked on the end but still has enough integrity…
I use Overature all the time (you should try the high-speed next time)… I found that it likes to be cooled. I keep the fans on. Here are my settings for it:
I would not speed back up at all. I print my TPU very slowly. It takes forever.
You are correct, it takes a long time. I dialed in the normal TPU settings which are the ones attached above. I decided to give the high speed a try. I practically used the same settings but nearly doubled the speed with great results.
I’m impatient Gramps! lol
I did have to dial it back when I printed with the CookieCad filament and that’s when I saw the real difference.
I do believe in the crawling before running.
It’s a common issue with the design of this handle and caused me to reprint many handles. Another maker showed me that if you have the modeling software (free version of Fusion will do this) you can remove the curved end and replace it with a 45 degree miter and it will print perfect every time. Visually, you can hardly tell.
