Centering Parts In A Drillpress

[rgsparber]

As I thought about Dorn's great observation of using a step drill, my mind wandered into other ways to find center over a range of gaps. This brought me to thinking about ways to find center over a range of widths. A VERY old technique is to drill 3 equally spaced holes in a bar. Put pins in the outer holes. To use, straddle the tool over a rectangle and rotate the bar until the pins touch the flanks. That center hole will be on the centerline of the rectangle.

OK, now turn this idea up-side-down. Mount a rod in that center hole and put that in the chuck. Here is a video of how it works:

Rick