A previous poster suggested a 3d printer. It isn't cheap but the possibilities are endless.
My son has one. He bought it with money he earned from camp. A newer printer prints better than a cheaper one. Filament can get expensive though. He learned a lot how to manipulate 3d objects etc. Printing techniques etc. peeling supports from prints is a lot of fun too. He is also sanding and glueing his creations.
The printing can take hours though. You need a place to keep it