Printing with TPU, any tips?

[WobblyHand]

On a whim, I bought a roll of Overture TPU filament. I understand it is a lot trickier to print than PLA and PETG. What settings do you use?

First layer head and plate temp, successive layers?
Fan settings?

I am using PrusaSlicer 2.6 alpha4, or 2.5.2. I'd like to get a moderately successful print. The bed temperatures allowed (25-60C) are rather wide.

 

[Flynth]

I can't help you with exact setting as they are exact TPU dependent, but let me say a word of warning about TPU sticking too well to PEI sheet.

If you have a PEI bed definitely use a release agent (glue stick) or do a series of tests starting with unheated bed and just a small cube of material, increasing slowly to see if it doesn't stick too hard. I read about people ruining their PEI by having TPU stick to it almost permanently.

I use two TPUs, a very soft one (FiberFlex 30D by Fiberlogy) and another one a much harder, cheap no-name brand. Both work very well, but the soft one is a lot more sticky and I print it on the bed at 50C if I remember correctly. Also I print mostly items that don't have high surface area contacting the bed(camera housings for fpv, gps mounts that don't break on impact but flex etc). If I did I would lower bed temp even further.

 

[WobblyHand]

I can't help you with exact setting as they are exact TPU dependent, but let me say a word of warning about TPU sticking too well to PEI sheet.

If you have a PEI bed definitely use a release agent (glue stick) or do a series of tests starting with unheated bed and just a small cube of material, increasing slowly to see if it doesn't stick too hard. I read about people ruining their PEI by having TPU stick to it almost permanently.

I use two TPUs, a very soft one (FiberFlex 30D by Fiberlogy) and another one a much harder, cheap no-name brand. Both work very well, but the soft one is a lot more sticky and I print it on the bed at 50C if I remember correctly. Also I print mostly items that don't have high surface area contacting the bed(camera housings for fpv, gps mounts that don't break on impact but flex etc). If I did I would lower bed temp even further.

I have been using Aqua Mist hairspray for the release agent. I had PETG stick to the PEI sheet and this cured the problem. There's still PETG visible on the sheet.

I used the settings for Amazon TPU (whatever that is) and experienced fine stringing and occasional small blobs. There's a setting to stay within perimeters that I can try.

My first pass at this was on a printed frog toy for my grandson. Came out moderately well, save for the stringing and my first attempt at TPU. For future prints need to control the stringing and blobs better. Frog is about 60mm wide.

There's a small burned bit that somehow got printed. Think I printed at 235C and 50C bed

 

[Ken226]

I have been using Aqua Mist hairspray for the release agent. I had PETG stick to the PEI sheet and this cured the problem. There's still PETG visible on the sheet.

I used the settings for Amazon TPU (whatever that is) and experienced fine stringing and occasional small blobs. There's a setting to stay within perimeters that I can try.

My first pass at this was on a printed frog toy for my grandson. Came out moderately well, save for the stringing and my first attempt at TPU. For future prints need to control the stringing and blobs better. Frog is about 60mm wide.
View attachment 443165
There's a small burned bit that somehow got printed. Think I printed at 235C and 50C bed

I've been using the same thing for years as a release agent. I tried glue sticks, and decided it was too messy. Aqua Net, Aqua Mist, or whatever is on sale, works awesome. A can lasts a long time.

I use Overture High Speed TPU, and set up my TPU profile using midrange settings base on what was printed on the spool. I did some test prints and fine tuning on the settings.

The first few times I printed tpu without a release agent, it stuck so tight that it ruined both the part and the pei liner on the sheet. Replacing the pei liner on the spring steel build sheet was a nightmarish, acetone fumed hell that I won't ever repeat. As bad as it sucked on the Flashforge's little 5x9" build sheet, I wouldn't even try it on my Voron's 12x12" plate. I always use a squirt of aquanet with either tpu or petg.



Here are some screenshots of my Flashprint TPU settings. These are basically Flashprint's default TPU settings, but adjusted to more closely reflect the temperatures printed on the spool. The print speeds are a little higher with the Overture High Speed TPU than the default TPU settings.

 

[WobblyHand]

I've been using the same thing for years as a release agent. I tried glue sticks, and decided it was too messy. Aqua Net, Aqua Mist, or whatever is on sale, works awesome. A can lasts a long time.

I use Overture High Speed TPU, and set up my TPU profile using midrange settings base on what was printed on the spool. I did some test prints and fine tuning on the settings.

The first few times I printed tpu without a release agent, it stuck so tight that it ruined both the part and the pei liner on the sheet. Replacing the pei liner on the spring steel build sheet was a nightmarish, acetone fumed hell that I won't ever repeat. As bad as it sucked on the Flashforge's little 5x9" build sheet, I wouldn't even try it on my Voron's 12x12" plate. I always use a squirt of aquanet with either tpu or petg.



Here are some screenshots of my Flashprint TPU settings. These are basically Flashprint's default TPU settings, but adjusted to more closely reflect the temperatures printed on the spool. The print speeds are a little higher with the Overture High Speed TPU than the default TPU settings.



View attachment 443166

View attachment 443167

View attachment 443168

View attachment 443169

Thanks for that. I just looked on the spool label and saw the recommended max temp was 230, and I was using 235. I will back it off and try at a lower temperature. Right now it is raining so not a great time to print TPU.

The All Weather Aqua Net Unscented Hairspray is pretty effective. I spray it to get the surface wet, then wipe up the excess with a paper towel. I can usually do two prints in the same location before having to redo it. If I move to different locations on the platten then I can print more before reapplying. The hairspray is relatively cheap, and you don't need much.

 

[Safety Crocs]

I use overture TPU too, I have had the best results with a bed temp of 30 and If I remember correctly I print with a nozzel temp of 225. For fans I try to set then at the minimum I think I get away with given the amount of overhang/detail on the part.

 

[WobblyHand]

After a while of ok but not great TPU printing, I started having problems. Still too much stringing. Have knocked down the temperature quite a bit and things are a little better. Occasionally the TPU would jam in the extruder and then would print nothing. This seemed to get worse over time. Recently I was 0 for 5 in printing a larger object. Smaller objects would print fine, but larger ones didn't. The failures didn't happen right away, they would happen 10 hours into a 12 hour print, which was quite frustrating.

It seems I had the tension too tight among other things. So I backed it off.
Other things that I had to fix.

• Reduce the retraction speed by over 1/2.
• Reduce the print temperature to 218C. The default settings were too hot for this filament.
• Disable Input Shaper
• Slightly reduce max volumetric speed

 

[brino]

@WobblyHand

Running TPU is still something I have not tried.
Thanks for your guidance, I will bookmark it and use when I do!

Brian

 

[WobblyHand]

@WobblyHand

Running TPU is still something I have not tried.
Thanks for your guidance, I will bookmark it and use when I do!

Brian

I'm finding it very difficult to print a larger model in TPU. Small one's are relatively easy. I had to back off the tension a LOT. When there is no filament, the springs need to be loose (untensioned). Currently 0 for 6 in printing a large model. Been quite frustrating to print hours and hours then have a filament jam spoiling the print. Seems an extruder jam is unrecoverable, unlike running out of filament (if you had a sensor).

About to throw in the towel on this, been at it for a couple weeks with little to show.
Last flop went until 37.4mm out of 180 mm. Jammed during the internal infill. Best one got to 111mm out of 180mm. This latest try is a 20 hour print. If it doesn't work this time I need to try something completely different, probably a total redesign and smaller in size.

 

[brino]

@WobblyHand

I certainly understand the frustration.
I wish I had some input to help with the situation.

I have read that TPU filament is more sensitive to nozzle temperatures.

Are you using a tent/enclosure ?
I have tried some simply ABS prints and they seemed to warp from the print surface.... of course we moved the printer out to the (cooler) workshop so that the fumes would not offend those in the house. However this does NOT seem to be your issue.....

Is the filament form a trusted supplier?

Brian