Quote:
Originally Posted by corksil
@ Mechanikrazy -- widening an existing hole in a copper washer is a bugger to accomplish. The washer has to be held securely which cannot happen horizontally in a bench vise because the washer deforms when squeezed. I suppose I could try to clamp it vertically but even with a brand new sharp drill bit, cutting oil, and very high speed with light pressure -- the washer tries to bend sideways.
My attempts at punching the copper with punches pictured further up in the thread haven't been pretty. The copper has to be backed up firmly (with steel) and once the punch breaks through the copper and strikes the steel, the punch dulls rapidly or shatters.
This is proving to be a bit of a riddle. |
Hope you find what you're looking for! Do you have a mill?
Instead of directly clamping the washer, I was imagining some kind of fixation. I haven't ever had a need for such specific washers, so haven't done this, so I am really just talking out of somewhere....
But I am imagining a square block of metal. Mill out a small recess slightly oversized for the washer, and of a smaller depth, so the washer sits above the surface. Tap holes, 3 or 4, on the edges of the washer recess to use set screws to really clamp down on the washer, so it won't rotate. Then you can just clamp the vise against the flat surfaces of the square block/holder, and mill out the ID to size.