That is indeed much smaller!

3D printing is great for making two part moulds btw! Tonight I cast this 60A Polyurethane onto the hub of an old castor wheel using a PLA printed mould. Feels very much like a banebot with treads now! To de-mould it easily I coated the mould in vaseline before casting, and then it popped apart very easily after the polyurethane had cured (about 2 hours). I like the idea of being able to design my own tread patterns and casting them onto whatever hubs I want.

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