Prusa i3 MK3S vs. very soft TPU - sponge effect
Hello world, I am struggling with printing from soft TPU. I followed some general recommendations - retraction off (Z-hop 0), all speeds 20 mm/s, loosen idler. Nozzle temp 200 C (filament recommendation 190-210 C), bed temp 50 C.The first attempt was the most successful one, but still unusable and the model was incomplete. 47 layers went great, then it started to make some kind of "sponge effect". The second attempt was great until 20 layers, then it became sponge again. For the third attempt, I changed the bed temp to 65 C and nozzle temp to 205 C. The third one was the worst, only about 15 layers ok, the rest sponge again. At least with the warmer bed, the first layer was compact.The filament holder couldn't be the problem, I have checked it many times and there was only around 10m of filament, so the spool is very light.Unfortunately, I couldn't be at the printer during the printing process, only in the beginning.I am attaching photos of all three results, plus the visualization. In the first attempt, I have already ripped off all the supports.
Please, does anyone know what could be the problem and how to fix it? Thanks...
RE: Prusa i3 MK3S vs. very soft TPU - sponge effect
I can print to 85A TPU OK on a MK3S+. First thing though is very dry filament. Even out of the bag new it still needs to be dried. Then I run at the top of the recommended temperature for the extruder. I print even slower if it's acting up, like 15mm/sec until I know I've got it all working correctly. If it's softer than 85A all I can say is that's going to be a challenge.
RE: Prusa i3 MK3S vs. very soft TPU - sponge effect
Hi Eric, thank you for your advices. I haven't followed the one abou drying, I tried the original filament unpacked four days ago. But still, the result now is great 🙂 I have raised the nozzle temp to 215 C and reduced the printing speed to 15mm/s. So once again, thanks a lot!
I have found out that the filament is regular 92A.
I haven't followed the one abou drying, I tried the original filament unpacked four days ago.
Then you are lucky to get a decent print at all - TPE's can absorb problematic amounts of moisture in a few hours, sometimes the start of a long print with an unprotected spool is perfect but the upper parts are badly affected by damp absorbed *while printing*. However, slowing the print and paying careful attention to the print temperature are the other fundamentals so well done on getting those right. Different filaments will have their own characteristics so expect to tweak the settings if you change.
Cheerio,