Silicone rubber tracks (3d printed moulds)

thingiverse

Making tiny vehicles is tough, and one of the hardest parts is finding suitable wheels that don't break easily. Most of the time, you either have to put up with hard plastic wheels or hope you can scavenge them from a toy. But the robotics community has found a clever solution: silicone rubber moulding. You can 3D print a mould, fill it with silicone and an accelerant, and get a custom tire that looks exactly like whatever you want. I wanted to make a tiny tank that actually had tracks, so I needed some realistic tracks. Typically people buy Lego tracks, but I didn't have any, and I couldn't be bothered ordering them. So, here's a way to make your own tracks at home. To use the moulds effectively: 1) Print them out 2) Snap the inner mould into its two halves 3) Mix silicone with flour or cornstarch or icing sugar or glycerol. These act as an "accelerant" and reduce the drying time significantly. The more you add, the less grippy the track will be, the less you add, the longer it will take to set. 4) Fill the outer part of the mould with the silicone mix, pushing it into all the treads 5) Coat the inner parts of the mould with silicone, making sure everywhere is coated as thin as possible 6) "Glue" the inner parts of the mould together with silicone and wrap some polyester thread around them (this stops the tracks from being stretchy) 7) Push the two parts of the mould together. There are some alignment tabs to keep the inner/outer parts aligned. The inner mould should fit flush inside the outer. 8) Wait an hour or two for it to set 9) Remove the inner mould. If you use a thin piece of metal, you can bend one half of the inner mould so that it clips past the other inner-mould-piece. By doing this, you can avoid putting unnecessary force on the tread lugs. I've also included an idler wheel and a drive wheel in this tutorial. They mount 42-43mm apart. I plan to make a more detailed instructable in the near future with even more information on how to make these custom tracks at home. Edit: I noticed an error in the STLs and fixed it a few minutes after publishing, but some people had already downloaded it. If you downloaded it within the first five minutes, you should probably re-download again. Also, the moulds aren't showing up in the preview, but they are there in the files tab.