- Joined
- Jan 29, 2013
- Messages
- 114
I Just use an electronic edge finder with a cylindrical (NOT ball)end. With the spindle locked so that the finder touches the arc of the circle (anywhere), the DRO is zeroed on this side of the circle. Then without moving the height or unlocking the spindle, move around the part to the other side of the circle. Bring the edgefinder in contact again, recheck and then use the DRO reading at this point to divide by 2. Then raise the spindle out of the way and run the DRO to this calculated number. BAM! Your are within .0002 (or whatever your machine will really do) of the center. I do this constantly when drilling centered holes in round stock or doing keyways. Fast simple and as accurate as your equipment.