How about letting the students make something useful, and possibly sell the items on CNCZone, to offset their tuition costs?
Bearing blocks for leadscrews, acme leadnuts, etc. are all essential components of homebuilt CNC routers. Your students might just get the CNC bug and decide to build their own!
Here's a link to a great site, it also has some prints of CNC components that your students may find interesting.
http://www.5bears.com/cnc.htm
Diplomacy is the art of saying "Nice doggie" until you can find a rock. - Will Rogers