Projunk's Omniwheel Barrel Casting Form

thingiverse

I've tried projunk's parametric omniwheels, a fantastic part for robots. We printed its barrels using FlexFill with great success on carpet surfaces, but encountered issues when using it on smooth surfaces. Next, I experimented with casting the barrels from very soft polyurethane (Shore A20) using this mold. This should make the wheels more versatile and usable even with other materials. As a complete beginner in casting, any suggestions for enhancing the mold or process would be greatly appreciated. To assemble the mold, use 3mm screws to secure it together. Ensure correct orientation by aligning the text on both sides of the mold parts in the same position. Before casting, insert axles into the mold and apply clay around the axle bottom holes to prevent material leaks. Similarly, apply clay to the edges where the two mold parts meet. Casting all 8 barrels at once is essential due to potential liquid material leaks between adjacent barrel cavities. The required amount of material for 8 barrels is approximately 17ml, sufficient for preparing 20ml of material. I used a 20ml plastic syringe with a small piece of shrinkable tubing attached to the needle hub to facilitate filling the cavities. Fill each barrel slowly until liquid leaks from the air holes around them. Without using any removal agents, it was extremely difficult to open the mold and retrieve the barrels without damaging it. Good luck! After removing the barrels, carefully cut off excess material with a sharp knife; avoid ripping it off. To prevent unwanted friction between the barrel's sides and the wheel body, print 1-layer washers and attach them to the axle on each side of the barrel.