Chopping Mortises for Wedged Tenons
A design for sofas and chairs our shop recently built specified that the arms be attached to the front legs by wedged through tenons. I solved the problem of cutting a mortise with consistently tapered ends for the wedges by first wasting most of the mortise with a plunge router. Then I chopped out the ends of the mortise with a sharp chisel guided by this fixture (above) that controlled the chisel angle and its lateral drift.
Joseph M. Wilson, Pictou, N.S., Canada
Fine Woodworking Magazine, February 1994 No. 104