I was coming up with some ideas for an elevator carriage that would be able to direct cubes in all 4 directions and found that I would need a compliance wheel larger than anything I’d seen being sold. I thought that perhaps I could CNC a mold and cast my own wheels out of 30A resin.
Any thoughts on this? I’m not away of a post about the topic yet, and I’m wondering about the feasibility of the task.
It is certainly doable. (https://imgur.com/a/zhdHD) I stretched them over pieces of McMaster 3/4" hex tube and they worked fine. By that time the AM wheels came and they were great. It is only worth doing if you want a custom size.
We made our own last year using Ninjaflex on our Lulzbot 3D printer. They were definitely flexy enough bit we ended up not using them. I realize that this is a very specific circumstance, and that you might not have access to either the machine or the Ninjaflex, but maybe there’s someone near you that does. Best of luck
One option that I have heard of teams doing is purchasing the TPU material which is used to make the wheels themselves and then simply water-jetting bigger wheels. You could design them to be as big as you want, and this would allow you to avoid having to set up a mold. Depending on the size of the wheel, I wouldn’t be surprised if the torque from controlling a cube would actually cause the plastic to spin on a (hex) shaft–if that’s what you were planning on using. I’m pretty certain that’s why the 4" options from AndyMark actually have a plastic hub embedded inside them.
TPU does run pretty expensive, so you could also find a different material to use. Just an idea
Dang, beat me to it…
For anyone who’s interested, there’s a https://www.youtube.com/watch?v=(https://www.youtube.com/channel/UCUbDcUPed50Y_7KmfCXKohA) that uses this filament a lot for wheels.
I printed some of the AM red ones in TPU last year. They were okay, but were not great at all. They flexed fine, but they were just not grippy.
I’ve casted urethane wheels numerous times. Usually I’ll 3d print a positive, use it to make a silicone mold and then pour the urethane resin in to that.
I’ve also had urethane tubes hot cast by a local urethane shop. The shop then cut the tube into sections on a lathe with a mandrel and a razor blade in the toolholder. Hot cast urethane wears slower so you can use a lower durometer.
We actually water-jetted 50A durometer rubber material we found on mcmaster and made our own “compliant” type wheels for our shooter last season.
For the cost to purchase and make them, lets just say it was easier to just purchase them from AM.
For custom sizes, sure, but for what most teams are using them for this season, we just bought them instead.