metal arcade contol panel 3" trackball hole cover

Here is a useful model for printing 3" trackball hole fillers for metal arcade control panels. Just pop it from the back, and cover the back with duck tape or something to keep it from falling out from the back (it will not go forward as it is designed larger in the back)

This design allows the hold to be flush on the top so control panel overlay can be applied without having visible "bumps". you could put it in with the larger side on top instead of the bottom and then no tape would be neede