I've been working on a larger project that requires some dowel joinery, so I picked up some dowel centers. I also needed a center finder to mark the middle of the edge of a board. Why not use the dowel center to make the mark? In this video I design a 3D printed center finder that uses a dowel center to mark the wood.
The center finder was designed to fit the 1/4" dowel centers from this set: http://amzn.to/2hLTUT6
If you'd like to print your own, the 3D model can be found here: https://www.thingiverse.com/thing:2667068