John, it’s a really simple approach to the problem. May I make a
couple of suggestions to make it work a bit easier?
First, before you saw the slot from the side to hold the sheet,
increase the size of the hole from what will become the backside
for a depth of about two thirds the length of the total. This
depth will still be below where the slot from the side will be
placed. What the relief does for you is to allow the disc to drop
free once it is into the larger area. This will also allow the
rod to be removed more easily, as the slight burr that is created
when the disc is sheared from the sheet tries to wrap itself
around the end of the rod. Since this burr is trapped between the
proverbial rock and a hard place, it makes the rod difficult to
remove. I utilize this increased relief diameter approach in
another application, that although for a different purpose can be
used to help visualize John’s method. Take a look in the “Learn"
section of my web page under “Forming hemi-spherical beads”. If
the slot were sawed in the 1/8” tall forming area, you would
have John’s die. You would of course increase the length to
provide better registration.
Second, if you were to use a bit of lubrication on the punch, it
would make the removal easier.
Bonny Doon Engineering http://www.bonnydoonengineering.com