Ninjatek TPU Diminishing Extrusion
Hey Prusa Peeps!
I thought I had this stuff mastered but I certainly don’t….
I’m getting diminishing extrusion with my Ninjatek Chinchilla TPU. VERY soft (75A). I have had the same print with every setting the same print just fine. It seems to loose extrusion as the print progresses.
I’m thinking it might be something mechanical. i.e. Bed level, bolt filament tensioner etc. Although all that seems okay.
Wondering if anyone has had similar issues with a soft TPU?
.3mf attached but really don’t think that’s the problem…
RE: Ninjatek TPU Diminishing Extrusion
85 is as soft as I go on TPU but I find I have to print it slower then the 92 I also print. Don't know what your print settings are but I would be printing it very slow at first while trying to get a feel for how it will work. Me, I'd start at 10 or 15mm/sec and go from there. Are you checking your extruder gear to make sure it's not all gummed up from the soft filament? That can easily happen.
RE: Ninjatek TPU Diminishing Extrusion
Thanks for replying! I'm already at 10mm/sec and 6mm/sec for the first layer which seems to be where the problem is. Constantly fiddling with extruder gear. Seems like the next print wouldn't always start just fine if that was the problem. Still would like to make it the number one culprit just can't figure out given the symptoms thats what it would be.
I need a really soft filament for this application but maybe should give 85a a go. Just would like to identify the specific problem before moving away. I do get it to print fine on occasion with same settings.
RE: Ninjatek TPU Diminishing Extrusion
Just another thought. Have you ruled out wet filament? I know I have to dry mine before use but I live in a very humid environment. Times like this you sure try to imagine every variable that you can nail down....
RE: Ninjatek TPU Diminishing Extrusion
Don't think so. A Ninjatek engineer to me himself that this filament doesn't need drying and both my successful and unsuccessful prints have not been dried. Still would explain the consistent great start would it? I could try it!
RE: Ninjatek TPU Diminishing Extrusion
Just following up on how you went with this one. I am having the same issues using Polymer 95A TPU. I just wanted to see if you solved this yet? 
RE: Ninjatek TPU Diminishing Extrusion
So the conclusion I have come up with is that my thermistor is off. Make sense as I have replaced my hotend multiple times and the new hotend has to be completely by me...a relative newb. I believe at this point I was losing heat do to a faulty reading and this TPU is very sensitive to a particular range.