1 Print 2 in any color you like, if you want wheels in different color (like black). 2 Glue Wheels in holes, big wheels at the back ;-)3 Insert earring hangers in hole through digger cabin. When I printed at the local fablab the holes for wheels were a bit to small so I enlarged them a bit. Once I get my own printer up and running I will experiment to come up with the ideal sizes.Include files:digger.scad: the design file so you can change it to your hearts content.digger.stl: just the digger body.wheels.stl: just the wheels so the can be easily printed in a different color.digger_and_wheels.stl: to print digger and wheels in one go.