Engineering-type projects:
- calipers
- making a set of 1-2-3-blocks
- making office desk accessories — the classic is a tape dispenser
- making a hammer with 3 removable faces (one stored on the pommel of the handle)
Easiest materials to cut/source:
- HDPE from cutting boards — I source from a local restaurant supply, but there’s Ikea, or if you have one locally, 4x8 sheets from Menard’s — an alternative is PVC lumber from a home center
- Lauan plywood / underlayment — cheap, and quality can be uneven, but usually cuts well with a downcut endmill and is quite affordable
- aluminum from soda cans — the last time this came up Apollo’s robot design came up: Recycling with CNC: Soda POP Robots
For endmills, I’d suggest a #201 (with some sort of coating if doing metal/plastic) or a #251 (my new favourite) if cutting wood/plywood — might want a #301 if using it for joinery.
also see: Can you suggest common material for 600 students? (ShapeOKO 3)