Joinery routing guide
Reach for your router and this jig to cut clean, accurate dadoes, rabbets, and half-laps.
Start with a plywood base
To make this jig, cut a 3/4x8x18" plywood base, shown in the drawing. Then cut the remaining jig parts from a 2x48" blank that's a hair thicker than your workpieces. Drill countersunk pilot holes and screw the 18"-long fence to the base with the edges and ends flush. Place a workpiece against that fence and butt the edge of the 13"-long fence against the workpiece. Drill and screw the 13" fence in place.
Quick Tip: Add shims for clearance. If you don't have a planer to size the fences thicker than your project parts, raise the fences by inserting kraft-paper shims to provide clearance. Now drill and screw one router guide 90° to the two fences and flush with the end of the 13" fence. Then place a scrap the width and thickness of your workpiece in the jig under the router guide and clamp it in place.