Support material for TPU?
I have had good luck with the TPU sticking to PLA, and no issues getting the PLA to stick to the bed (XL with multiple extruders). Using PLA as the primary for the wipe tower solved issues there. However, there is a portion of the print that is essentially inside of a TPU tunnel and PLA needs to stick to the TPU on the bottom to support the top portion later. None of the organic supports stuck at all. I ended up with a spaghetti rats nest of PLA that eventually provided some support, but I need something that will stick to a finished TPU surface.
I have some polyDisolv that claims it works and will try that. Also have PETG I can use on a test print. The TPU being used is the ColorFabb Varioshore and my original test print appeared to work fine. Will redesign the test print to better expose the lack of adhesion, but wondering if anyone has had any better luck with other materials.
Hard to say without seeing the geometry but this *might* be a case for custom support. Build it where you need it, don't rely on the slicer - organic supports wouldn't be my first choice for internal tube supports - I might, for example, run a custom bridge support in CAD and paint snug support on that in slicer.
Cheerio,