The last time I punched a hard drive platter, I lathe-turned a bushing to center the Greenlee punch:
This will work better:
The OD centers the bushing inside the punch body, the ID captures the screw, and the raised boss captures the platter.
After drilling the platter on the new fixture, it’s ready for punching:
Line everything up, turn the screw, and It Just Works:
The masking tape holds the platter to the bushing, eliminating the need for a third hand. The bushing emerges unscathed, ready for another platter. Overall, I think that’s faster and less messy than milling the platter ID on the Sherline.
Printing out a base to fit the Duodecar socket and assembling all the parts:
The Duodecar pin circle (19.1 BCD + 1.05 pin diameter) will actually fit inside a hard drive platter’s 25 mm unpunched ID. It might look a bit squinched, but the less you see of the socket, the better. I’ll try that on the next one.
The OpenSCAD source code is the same as before; set
Layout = Bushings; and a bushing will pop out.
The original bushing doodle with dimensions: