> ball race drawer slides maybe with a return spring Printer carriages have very good guide rails and transports. So do 5 1/4" floppy drives. And both good enough to mechanise with a small motor I reckon, if you want push-button drilling -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist