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AW Extra 1/16/14 - Mortise Centering Jig


Mortise Centering Jig

With this jig I can rout mortises exactly centered on the workpiece— no measurement or layout necessary. First I drilled and tapped two holes in my router base plate to take 10-32 machine screws. Both holes were located directly opposite each other along a line that runs through the center of the router base. Then I mounted roller bearings with lock nuts and washers, as shown in the illustration. Finally I cut slots in two 1-1/2 by 1-1/2-in. guide beams to match the diameter of the bearings. Make the beams about 1 ft. longer than your longest mortise.

To use the jig, lay the beams on the bench with the work face down between the beams. Clamp the assembly, turn it right side up and put it in a vise. You can either mark the limits of the mortise in pencil or clamp stop blocks.

This story originally appeared in American Woodworker April 1999, issue #72.

April 1999, issue #72

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