3D printer and CNC are sort of too specific ... at that age, for most projects, cardboard prototypes are better (cheaper, faster, more rewarding, more parallel). Pottery is even better though because it becomes a permanent piece and lets you do painting as well.
In later school maybe basic robotics works with a pi... lesson by lesson skill building like "synth speech", "parse speech", "sensor data acquisition", "internet query", "database 101", whatever...
3D printer and CNC are sort of too specific ... at that age, for most projects, cardboard prototypes are better (cheaper, faster, more rewarding, more parallel). Pottery is even better though because it becomes a permanent piece and lets you do painting as well.
In later school maybe basic robotics works with a pi... lesson by lesson skill building like "synth speech", "parse speech", "sensor data acquisition", "internet query", "database 101", whatever...