3D Printed Wheel + Axle, Parametric

Here' a basic, parametric definition for toy wheels, created in Rhino + Grasshopper.

The "axle" has a square shaft for assembly into whatever vehicle you dream up. The part is generated with a user-defined gap between the hub and wheel (0.4mm worked well for me). You can also include a through-hole to use a nail or screw for a more durable toy. In the included photo, I've used a small nail to lock in the 3D printed wheels. The nail does two things: (1) reinforces the plastic where the hub nar