Hole centering aid

[Toolguy]

Hi Marv. Just stick the straight end of the edge finder in the hole, center in X axis by eyeball. Move in Y axis to touch off the back of the hole (when the touch probe kicks off) and zero in Y. Move to the front side of the hole in Y axis and take a reading. Divide this number by 2. That will be the center of Y axis. Move to center of Y and rezero. Touch off the left side of the hole in X axis and zero X. Touch off the right side of the hole and see what that number is. Divide by 2. That is the center of X. Move to the center of X and rezero. You now are in the center of the hole. You don't have to know the hole diameter or do any math besides dividing by 2.

You can find the center of a pin the same way, just on the outside instead of the inside. Carefully approach the edge that the edge finder will touch to get an accurate result. The cylindrical part of the edge finder is .200. If the hole is too small for that to work, you can use the pointed end the same way. In actual use, this takes (me) about 30 seconds to do. My edge finders will repeat to a 1 or 2 tenths. You can check the position with a DTI in the zero-it.