Comment Parts (Score 1) 970
Where I am, there's a local surplus store that does robot workshops once or twice a month. Most of the motors, gears, etc come from scrap printers - they'll pile them out back, and recruit the kids and adults in the workship to rip them apart and collect the parts they need. Whats left over, is sent off for scrap/recycling.
Not only does it help teach the kids how to build things, but they learn the value of salvage and reusing components.