> > On Tue, Jul 28, 2009 at 4:47 PM, Jinx wrote: > >> 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 > > > > Yeah, just took a trip to my hardware store. The door hinges have a > > lot of free play on them. No good for this. The drawer slides are > > loose as well. I'm just waiting for someone to throw out an inkjet or > > something. > > -- > > Might be kind of a stretch, but what about the mechanism in a scissor jack? > - Marcel All too complicated. Take two planks, say a metre long, with one about 50-100mm longer than the other. Put the short one on top, and put hinges at one end to join them together. (Wider boards are better, less sideways movement.) Hinges should be tight-ish rather than loose-ish. Clamp the Dremel to the short top bit, and put the PCB on the lower. You need some way to lift the top bit up so the drill bit clears (spring, bungee cord). Hold the PCB in one hand, pull the top board with the other and there's your hole. Rinse, lathe, repeat. The idea is that the drill actually travels in an arc, but the distance is so small (a few mm) that it doesn't matter. Very old idea apparently. I've seen one version where the boards were triangular with the Dremel at the tip. Lots of hinges at the triangle base removed any play. Tony -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist