I've started my next project, which is to design and print myself custom shoes. I'm gonna start with something simple: pool shoes.
Pool shoes are typically designed to be close-fitting and put as little material around the foot as possible. So they're ideal to iterate through the design of my shoes to find the perfect fit without wasting too much filament. And I need a new pair anyway...
I ordered a bunch of TPU with different Shore hardness and the rolls have arrived. So now I'm designing the shoes.
I have no experience with TPU, but a colleague at work does: he told me he tried to print a remote-control-like flexible sheet of rubber buttons that was 2mm thick, and the sheet readily delaminated when he pulled on it.
I want my pool shoes to be as thin as possible - apart at the front where I need protection. So bearing in mind what my colleague told me, I opted for a wall thickness of 2.5mm. Do you think this is enough?
As for supports, the printer I use at the moment only has one extruder head (it's not mine) so I'll have to print them out of TPU too. Is there a good strategy to limit the amount of material used and maintain structural integrity on such a large print? I'm thinking of drawing the supports myself inside the shoes to control exactly where they will be and limit wastage.
I've done many TPU prints that were stressed to hell and they hold up amazingly well. Like 2000 lb shock loads on little 2mm walls, hundreds of times, and not tearing or delaminating. Ninjatek Cheetah and Fiberflex 40D mainly, but others seem to hold up really well too.
I printed wheels for my kid's folding wagon 1.5 years ago or so. They have TPU treads that are around 5mm thick with three walls and 20% infill for some sponginess. They've heald up really well. They've been over curbs, rocks, and tons of other surfaces from 2 seasons.
I did tank tracks in TPU - I've since stopped using it, but not because they broke, but because they keep stretching. Removing one element after 10 minutes of play becomes annoying over time. Though I am somewhat curious how long I could continue doing that before something breaks.