Doweling Jig Helps You Center Mortises
When I built a project with several mortise and tenon joints, I found a quick way to drill out the mortises and keep the bit perfectly centered on the stock. I use my self-centering doweling jig to keep the drill bit lined up properly. I drill the hole at each end of the mortise first, then drill out the stock between the holes.
—Brian Grams, Gillette, Wyo.