This filament is even worse than silk and that’s saying a lot. No level of calibration seems to be effective. But I have a project that requires a special shaped gasket be printed and so far, I’ve had very mixed results, way too much stringiness.
Anyone had success and how did you do it? I tried, temp tower, retraction, pressure advance, it still comes out looking like a stringy mess. I was able to get some acceptable but not perfect results using 50% speed and cutting the max flow rate from 3.5 to 3 but I’m hoping there has got to be a better way. The principle problem is stringing and layer adhesion.
May need to dry the filament, as it tends to string more when it’s not dry. I’d also suggest enabling “Avoid crossing walls” which will help reduce the visible stringing. I typically print at the higher end of the temperature recommendations of my TPU filament which makes for for strong layer adhesion, but does produce more stringing for me. I’ve never been able to fully get rid of all stringing with TPU though.
I bought TPU filament from different manufacturers, also from BL. (Some colors you get only from …)
The only one I tried till now is the first one I bought. From yousu. It worked very vell with the default settings from BL-studio. I dried it first about 5 hours and printed directly from the dryer.
One more note: I used the hight temp plate and left the door open.
@Olias, I feel your pain on this one. I know you are keenly aware of the dryness factor so let’s assume you’ve addressed that. Changing to .6 nozzle can help, but I’ve printed successfully with .4 too. If you’re doing a gasket then I picture a circle or at the very least a continuous path (like a racetrack). Try making sure to avoid passing over holes. Also try using the concentric print pattern instead of rectilinear. HF TPU will probably give you the best print result, but not really a usable part if you are looking for air or water tight. Lastly, stick with the default profiles. I went down a dark and deep rabbit hole to no avail on that one.
Edit: I recall you don’t use Bambu Studio as your main slicer. Maybe at least for this, eliminate the variable of using an alternative slicer.
Ah ha!!! Didn’t consider concentric. Yes, you were spot on. I am printing a circular gasket. But I have to confess. I was too lazy to dry out the filament since it was in a bag with a desiccant and a digital hygrometer that indicated less than 35% humidity. The spool hadn’t been exposed to moisture prior to that but we all know that means nothing. I’ll have to take the plunge tonight and dry it out.
I used Polymaker TPU and used the Overture TPU profile found on printables. I also did a short dry cycle in my filament dryer, even though I didn’t really need it in my house.
Well now. Turns out I violated the first rule of trouble shooting, change no more than one thing at a time. But it worked and I was short on time.
So here are the things I did.
Dried the filament at 40c for 12 hours while I was away.( forgot to weigh before and after, I’m such a dumbass, now I won’t really know how much moisture played a role)
Set the printer at 50% quite mode.
Set infill to 100%. Since this was a circular gasket, that probably didn’t matter.
Set print pattern to circular as our esteemed colleague @Level23 suggested.
Filament was 200g Gizmodorks TPU filament – at $1.55/oz OUCH! – using standard Bambu TPU 95a default profiles simply because none of my tuning efforts, as was indicated in the subject line, seemed to perform any better. Used 0.08 layer height printing profile 0.40 nozzle.
Overall, I am satisfied with the results but there’s a reason I didn’t want to by a full TPU spool. There are few uses that I have had where I need to print anything larger than a gram. All of them have been gasketing material. In this case, this is the largest TPU item I’ve printed thus far at 1.57g. I don’t see myself printing any Crocs any time soon. So a 200g spool should last me a while.
Edit: This is what the model looked like as PLA that I did just to get a baseline expectation of what was the shape supposed to look like when all things being equal. This was done at regular speed an at 0.28 draft layer height. It’s using a junk PLA someone gave to me.
It may not matter as much on your round model but what pressure advance setting did you use? When i calibrate TPU, depending on the method used, i’m all the way up between 0.4 and 0.5.
In the end, I threw in the towel and gave up on calibration of the filament profile. I wasn’t getting a return on my time and decided to use the Bambu TPU 95 defaults which faired no worse than my 2 hours+ of trying to dial-in the best tuning. I did numerous attempt at pressure advance tuning but the patterns that I printed showed zero, and mean zero, difference between one end of the parameters to the other. In fact, the irony is that my best prints were PA Tower, PA pattern and retraction tower. They were all flawless… go figure…
In the end, it simply being patient and drying the filament and then the biggest difference was letting the part print at 50% speed.
Let’s just put it this way. If TPU filament were a person, they wouldn’t make it on to my Xmas card list.
I had some tpu 95a that was string a little, put it in the filament drier and forgot about for a few days. When I printed my part there wasnt any stringing at all.
Well, based on the feedback here and out of complete curiosity as well as the need to print another part, the 200g spool has been laying around in my office since the start of this post with 40% RH in the air. It had plenty of time to suck up moisture. I did nothing different with these two prints except one thing and look at the results side by side.
Lol this stuff is about a 3 out of 10 for printing. Try something harder like POM.
Tpu. Dry, slow print speed, slow retract and detract speed are key. And if using pei something like nano polymer down is a barrier if you don’t want to pay the part off a hot build plate or dump some isopropan all around the edges of the part peel it off.
So a 200g spool should last me a while.
