Customizable silicone tyre mould

This is a customizable version of the [antweight silicone wheel mould](https://www.thingiverse.com/thing:3275522), so you can change its size to suit your bot. You might need to experiment to get the inside post to fit snugly in the outside hole.

This is designed to work with [the matching wheel](https://www.thingiverse.com/thing:3578655). It might pay to make the tyre smaller than the wheel.