I am needing to round the corners of aluminum coil stock up to 0.040" thick but most will be 0.027" or 0.032".Have barely any experience in this area but am thinking of trying to make this myself somewhat as a learning exercise. I may be needing to do up to around 2000 hits but for right now the need is small so I have a little time to try some things. Thinking of doing something like this:
Attachment 344484
I need it to be bigger - about 1/2"-3/4" radius. It looks like this is self aligning so it could be used in an arbor press, especially if I extended the lower tube up and put small plates on each side of the opening to control rotation.
Rather than make the entire punch of hardened material I am thinking of using a piece of hardened material on the end. Perhaps 0.25" thick and pinned to the punch body. One thing I am not clear on is if the projection of the lower die edge into the die is supported below or is self supporting(round hole below). Haven't been able to find a view that shows but my guess is it is supported - which would make the lower body a little harder to make. I couldn't just start with a tube or if I did I would need to add a part inside.
I am also not clear on how much I need to allow for grinding after hardening and how I would do the grinding. Is it reasonable to do that on a milling machine with a high speed spindle?
It appears the die edge is pinned to the body or is one of those a screw?
Any thoughts or suggestions are appreciated.