Simple centering jig

This is a simple center-finding jig that will let you draw a centerline on a piece up to 2.75" (around 70mm) wide; I whipped it up when I needed to find the centerline of a piece of wood on a home renovation project.

Place it bumps-down along the edge and turn it as far as it'll go, and then you can use that as a guide for drawing a line with a pencil, giving you a perfect center for where to drill that hole.

If you need a larger size, just edit the .scad file and modify the ‘width’ value.