Hinge mortising jig
A real time saver, easy to make and use. The jig as pictured handles work pieces up to 3″ wide, and makes accurate mortises up to 4″ long with a palm router and 3/8″ bit. The dimensions can be adjusted for your own equipment and applications. The two “sides” are identical (except for the end stop threaded rod) which makes construction simple. A single setup can be used for hinges evenly spaced from the each end of the work piece. You can route from either side of the jig. The router base shown is for a palm router.
The jig on a workpiece. The end stop on the threaded rod and the mortise width stop can be set quickly. The router base is then set for the height of the mortise. Once done the jig can be swapped to the other end of the workpiece and then to other workpieces without further adjustment.
The jig on the other end of the workpiece. I've done 32 hinge mortises in 20 minutes without trying. Note that the edge guide of the router base must slide under the arm. There is a piece of sandpaper glued to the edge guide. This reduces required clamping pressure to keep the edge guide stable, and provides clearance between the edge guide and the arm.
Rather than cutting slots the sides and arms are glued up. The gap is 9/32". All stock should be jointed and planed for accuracy.
The parts of the jig that contact the workpiece should be wide enough to provide good stability and adequate friction when the knobs are tightened. It's not a bad idea to glue sandpaper on the pieces that contact the workpiece.