On this tangent I can recommend 3D printing jewellery and RC toys as well as repairing broken stuff around the house. Kids like custom fidget spinners.
Printing RC toys gets expensive fast. Before you know it you're buying castle motors and a flysky remote.
Oh fidget spinner is a good idea. I bought some good will with an articulated dragon that my daughter likes that is pretty cool.
Have you got any links/suggestions for the RC stuff? I've not looked into that yet.