[Amps] Hole punches

[KD7JYK DM09]

I've not used hole punches, ever, but, I've seen them used.  I've used 
5-flute reamers in the past, 5-flutes are supposed to not chatter, they do!

My most recent trick for 3/4" holes, which had to be perfect, as it was 
someone else's equipment, was to use a small drill, about 3/16", then 
larger, about 1/4", or 5/16", then I used some high quality countersink 
bits, 3/8", 1/2", 5/8", and 3/4".  The hole was flawless, no chattering, 
and no bending of the metal.

They aren't drill bits, so can't be pushed through, I just use a little 
pressure, and let them do the work.  It takes a while, but the 
countersink bits are easy to control, don't grab, a don't chatter, and 
don't bend the metal, turn up the edges, or raise burs, so this is now 
my go-to.  If I need to get down into something to make, or open a hole, 
I use a drill bit extension.

In one case, I could drill a 3/4" hole from the top of an item, but 
could only get to within ~2 feet of the bottom side.  I used a drill bit 
extension, and a round stone, like a ball, to sit in the hole from 
underneath, and smooth the edges.

Kurt