Drilling holes in my first Windsor chair seat, freehand, seemed a recipe for disaster so I adapted my drill press. With the hinged plywood leaf, two protractors and a pair of plumb bobs, I can drill a compound angle with confidence. I drew my protractors with a CAD program, but ready-made plastic ones would work equally well. You could also substitute large nuts for the plumb bobs.
-Lorne Davidoff
