Replacement switch key for some older Craftsman power tools, in my case a 8" 620-1300-3100 Craftsman Drill Press. Replacement part number is a bandsaw switch key #60256 or craftsman switch key #22255. Usually a $6+shipping part if you can find them

Printed with PETG filament 20% infill, rotated so it was printed on its side with support for mechanical strength.

Mine was a little loose in the machine's switch, and could fall out after a few on-off cycles, but otherwise functional as a safety key

Printrbot

Doesn't Matter

20%

Used calipers to measure the broken part and modeled it in Autodesk Inventor 2016. Pins and rectangular shape was pretty basic work. The curve was based on some educated guess work. I make some measurements from flat portions to the curved button to estimate locations for a few points, placed those points in Inventor, then used a 3 point arc to find a best fit curve.