How to Locate the Center of a Hole With an Edge Finder

[TomG]

A method of finding the center distance between the two gears would be to mesh them on the bench and actually measure the distance directly, allowing a few extra thousandths for clearance. You could even make a test plate to mount the shafts, to verify the hole spacing before boring the hole in the apron.

The good news is that if you screw up the first attempt, it can be fixed by using a larger bushing.