Manufacturing 3D Printed Molds for Small Robot Wheels
For my antweight combat robot DetCord, I wanted a wheel that could improve upon the Banebots wheels that I used before. I wanted something shock absorbing, which would extend the life of my gearboxes. The tires need to be soft and have high traction. The wheel does not have to be very strong because the robot has thick armour to protect the wheels. I ended up with a cool way to make a wheel that’s cleaner than the more popular methods I see on the internet! I can print the wheel hub in TPU with spiralling spokes for shock absorbtion. But 3D printed TPU is shore 95A and so doesn’t grip as well as the shore 30A Banebot wheels I already have. I need a tire that’s a softer material with high traction. I researched and found plenty of resources on how to make wheel molds for liquid urethane mixtures. But searching around I can’t find liquid urethane in low quantities, and the casting process sounded like a pain. I thought this would be a good challenge, the rules are: only use materials I can 3D print easily, and a single liquid that can be purchased in low quantities and doesn’t require mixing. So I ended up choosing TPU for the wheel hub, PVA for the tire mold, and “liquid gasket” as the tire. My mold is printed out of PVA, it’s a water soluble plastic. So…
