colinhester Messages: 1349 Registered: May 2009 Location: NE Arkansas
Illuminati (3rd Degree)
I need to put a couple of 0.75" holes in a piece of copper sheeting. Yeah, I know a chassis punch is the way to go, but I don't have one. Any ideas?......Colin
If it's very thin you'll need to sandwich it between 2 pieces of plywood and clamp. Thicker sheet means cooling as you drill, a squirt of 3 in one oil. Just use one of those 'bi-metal' hole saws you buy at Lowes/Home Depot. About $10. Be sure and clamp the workpiece to the bench or drill press table. If you don't, the workpiece can easily get away from you and spin. That's bad! Better yet, while you're buying the hole saw, see how much a Greenlee punch is over in the electrical dept.
Hole saws have worked pretty well for me. I use it free-hand with a hand drill. Just go slow and use a bit of lubricant like Bill said. I always make sure there's a nice thick piece of MDF clamped tightly under the piece of metal to make sure the bits don't wander.