Have people had much luck with PVA support on AMS TPU?
There has been a lot of hype about 3D-printing a TPU bellows flat with PLA interfaces: 3D Printed TPU Bellows With PLA Interface Layers | Hackaday I’m trying to make a camera bellows using TPU for AMS on the X1C, which means it has to be light-tight. The black AMS TPU reads as a TD of between 0.1-0.2, which means it might be opaque enough; the light through it isn’t the advertised 000000, but something like 0e161f – brownish. Incidentally, AMS TPU produces parts with shockingly high-quality surfaces; I never got anything so smooth using regular TPU on other printers.
The first thing I tried was a straight AMS TPU print of a square bellows partially extended: that worked, producing an air-tight bellows that is a bit too stiff for camera use. Next, I tried the much-hyped print-flat method with a circular bellows because I noticed that the corners in a rectangular one caused poorly distributed stress; that didn’t work because the PLA bonded to the AMS TPU too well.
I then made a better bellows design for the stiff-ish AMS TPU, this time circular with rounded inner and outer folds that are a 1/2-fold offset, making support critical during printing but reducing stress by essentially halving the local deformation needed for operation. I have tried printing it using PLA support in both conventional and tree patterns. Tree support took nearly twice as long to print and was closer to working, but the part was still destroyed by the process of removing the PLA. I also tried printing entirely in AMS TPU using minimal custom supports designed to be easily cut; that prints quite quickly, but it turns out that cutting the supports is very painful. It is this design that I’m thinking of printing with PVA supports…