Hello,
I’m currently printing TPU. It works well, but some parts are very thin and therefore have little grip. It works better with brim, but the brim is too weak for some thin areas. That’s why I would like to increase the brim by a few layers. Is there a setting for this?
Yes, just below the brim type in the “Others” tab are a number of brim settings.
Yes, there are settings there, but there is no setting to increase the layers for the brim. Only the skirt can be raised, which doesn’t help me.
Ah, sorry. I misunderstood.
Try decreasing the brim gap instead. It’ll be harder to remove but makes a big difference.
You may also want to increase the 1st layer bed and nozzle temp by 5°.
Or use a skirt with several loops, your chosen “brim” height and a much smaller skirt distance equating your brim-object gap.
Skirt only allows 10 loops, it does not reach the object.
I’ll be testing brim ears soon, but I’m not hoping for much.
Try a 0mm brim gap. That usually makes a big difference.
That was the first thing I tested, it didn’t help, the brim tore off.
Mhm, do you have a pic, screenshot or 3mf?
GoProStuff-RunCam_5_-_Session_5_mount.3mf (223,4 KB)
Many thanks. 
So you are using the 90A TPU? I am unfortunately not familiar with that but there are a few observations I made.
Did I spot the trouble area correctly? That should not really be a problem in this print. 2.5mm width with this geometry should not really need a brim.
Other items I noted is the lack of an increase in plate temp for the 1st layer. You may want to increase nozzle temp by 5-10°C and plate temp for the first layer. That should increase bed adhesion.
Another item I spotted is retract. It has nothing to do with print adhesion but may come in handy later. This may be more suitable for TPU:
To improve the first layer, you may also want to slow down on that layer. In particular infill. Further layers may be a bit faster than I’d usually print, but you did not report an issue with that.
The first layer using a Monotonic pattern leads to significant jerking. You may have better luck with a concentric bottom pattern. Also, avoid crossing infill.
You can counter potentially adverse effects of the wriggle reduction from a concentric bottom layer with the Arachne wall generator.
Provided that your filament is freshly dried (my TPU needs drying every 5 days if on the rear spool holder), this print should not need a brim. But you could in fact use a multi-layer skirt. The gap to the part in the preview also occurs with a 0mm gap brim.
Please dry your filament (again?) and try the bottom surface pattern and speed changes as a minimum, maybe also the temp changes. If you still have a problem, we will need a few pic’s (global and detail) of the failure to better analyze the problem.
Thanks for the detailed answer.
The corners always lifted.
I’ll test it tomorrow and give feedback with photos if necessary. I can’t do it today.
Corner lifting = Warping
Definitely dry your filament, slow down and follow recommendations above.
Furthermore, the bed temps in your 3mf are way below the data sheet. Use the data sheet recommended bed temp at least for the first layer. Unfortunately, there’s no softening temp given. Try 50° for the main print, 60° for the first layer but use a few lines of PVA glue stick evenly distributed across the build plate with a moist to wet cloth. Otherwise, you may have real trouble getting the TPU off the plate afterwards.
You may also want to decrease post-1st-layer printing speeds to stay within the spec sheets 50mm/s. I’d also close the door and lid (warping can indicate drafts and/or a too cold environment) but with many retracts, that may lead to an nozzle clog. You’ll have a few due to the intermediate “posts”. That is when the retract recommendations above come into play.
Good luck and 
I’ll test your advice later, thanks for that!
The AMS gave an error when I tried to use the “Generic TPU” profile. Then I built a TPU roller where I insert the filament manually. It works very well, even with y PTFE adapter.
But there is a profile “Generic TPU for AMS” that I only saw later. Can I also use the TPU 90A in the AMS with this profile?
Is the filament buffer useful for TPU?
There is AMS compatible TPU available. But it needs to be much harder than 90A. I have a roll of 58D lying around as that was recommended as minimum hardness before Bambu released their own AMS compatible hard TPU.
When printing soft TPU, it can be important to reduce friction on the way to the extruder as much as possible. 90/95A can be printed from the rear spool holder. Especially if seated on roller bearings like you seem to have done
Going softer is possible too. But forum members who have done it mounted the spool above the open printer and fed filament directly into the extruder without the PTFE.
To go really soft is unfortunately not possible without some small but important modifications to the extruder. When exiting the wheels, there’s a small gap of a few mm. Perfect for soft TPU to bunch up and wrap around the extruder wheel. An angled, stabilizing tube in this area is State-of-the-Art. But unfortunately not on the Bambu extruders (well, at least P1, X1, not sure about A1).
