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'm starting to wonder if I might be better off printing a mold out of PLA and pouring liquid rubber into it 🙂 I mean technically, the shoes would be 3D printed and it would probably create fewer headaches, because liquid rubber is what I use now with regular molds to create my shoes, and it works perfectly fine.
I'm a bit concerned that this whole endeavor will results in quite stringent requirements in terms of hardware, and difficulty in manufacturing, because ideally I would like my design to be reusable in developing countries for others who have a need for custom footwear like I do but don't have the money. My plan is to turn my FreeCAD design into a configurable OpenSCAD file eventually, that anyone with an el-cheapo printer and some time can use to make cheap bespoke shoes.
So maybe for cheap easy shoes to happen anywhere in the world, maybe a PLA negative and liquid rubber is in fact a better route.
But for now I'll go with the TPU: I have it so I might as well, and I'll learn something.