TPU for AMS support won't come off

Bambu Lab Software Bambu Studio
1

So I’ve been printing and trying (and failing) to get a good surface under the supports.

Been tweaking settings and now I’ve got it so what was difficult to remove supports to impossible. I’ve tried everything I can think of to get these supports off and they are stuck good. Prior I was able to get them off but the surface was poor.

I can’t figure out what I did to wreck it. I deleted all the models (forum wouldn’t let me upload w/ any models) from this 3mf so y’all could see the settings.
Handle V2.2 .6nozzle RevB - no models.3mf (17.5 KB)

I’d appreciate it if y’all could have a look and see what I wrecked.

2

I’ve been having good luck printing regular generic TPU w/ great results increasing the retraction up to like .7mm so I did that to this model too, I wonder if that’s causing the problems…

3

I thought it might have been the top interface spacing to zero, but I reset that to default and printed one and it didn’t help at all.

4

Increasing the retraction can help with stringing, but it might also contribute to the supports being too rigid. Have you tried adjusting the support density or maybe the support interface thickness? Sometimes lowering the density can make the supports easier to remove without sacrificing too much strength.

5

Thanks,

Rigidity of supports is what I’m trying to achieve. I think what I can see on the failed ones (successful print, but not shippable to a customer) that the supports are moving (it’s TPU after all) and that’s what’s giving the bad finish on the ones where I was able to remove the support material.

I’m running again with the last of my material (really burning a lot of this expensive material) with retraction set to default and hoping this will fix the problem with the supports not coming off.

6

Just making junk!!! It’s neither of those settings. I’m at a loss…

7

could it be the new software version? my problems started about the same time I ‘upgraded’.

8

I noticed with the new software update, all of my flushing volumes between different filaments was now set to zero for everything, which is wonderful (NOT) for multi-color printing. Have you checked to make sure those were not zeroed out.

9

I’m not doing a multi color print. It’s 1 filament, TPU for AMS.

This is not an underlying flaw in the material, it was working and supports were coming off, now it’s not. I jammed a screwdriver between the part and support and ripped it away, it’s bonded really well, like really well.