Hi guys -

I am looking for any tips and tricks for locating the center of a a hole for purposes of drilling a hole patter.

I have a chain sprocket (55 tooth) and it has a large hole in the center. I need to drill a 5-hole pattern in the sprocket, and this hole pattern needs to be as perfectly centered as possible. The hole pattern is 5-holes, or 72 degrees apart from the center.

I have a Sieg SX2 that I converted to CNC.

I plan to set the sprocket between 2 123 blocks and clamp it down.

Any help is much appreciated!