To use a laminated brace, there must be a 1/2” wide mortise in the leg. This is a simple process if you have the proper jig.
This is the jig that I used to make mortises for all of my mortise and tenon joints prior to purchasing a mortiser. I simply added some plywood to the base to raise it to the swing of my new lathe. I added a strip of plywood on the bottom to register it between the bed ways of the lathe. It is then secured by a scrap of hardwood that clamps under the bed ways by fastening a bolt through to a threaded fastener in the base of the jig.
Plunging the Mortise
Fasten the seat tenon of the leg securely in a lathe chuch and lock the indexer to prevent the drive end of the lathe from turning. Drill a hole in the center of the leg bottom. This is what registers the tail stock in the correct location. The plunge cut is 1/2” deep at the bottom side of the leg. The router is centered in the jig using an adjustable router fence. I mark the start and stop points of the plunge cut directly on the leg.
Here is what the 1/2” wide plunge cut looks like while still attached between centers.
Here are two pairs of rear legs routed and ready for squaring with a mortising chisel.
The next step will be trimming the braces to fit the mortises…
-- Mark, Florida