Versatile, inexpensive, and straightforward to make use of, Don Browning’s Mortise Grasp makes spot-on mortises accessible to any woodworker. The jig is at its greatest making matching mortises for slip tenons. Format is so simple as marking centerlines throughout the joint—the identical means you’d for a biscuit. Setup is straightforward, too. You begin by clamping the jig’s two thick wooden fences onto your workpiece and lining up your pencil mark with a scribed line. A skinny lip alongside the internal edge of every fence sits on high of the workpiece and ensures the fences are stage with one another.
The jig comes with a 1-in. bushing that you just screw into your router’s baseplate. As soon as it’s in your router, you match the bushing into the opening within the heart of the jig’s ingenious polycarbonate slide plate, which is the guts of the system. Together with your plunge router using on high of it, the plate slides backwards and forwards on the jig, guided by little UHMW plastic blocks that connect to the slide plate in varied positions and glide alongside steel T-tracks, making the mortising motion clean and exact. Those self same tracks information the 2 polycarbonate fences that act as stops, limiting the journey of the slide plate (and subsequently the size of the mortise). The really helpful upspiral carbide bit (provided by you) ought to correspond to the width of the mortise. To rout a mortise, you set the depth in your router, match the bushing into its gap within the slide plate, and hit the on-switch.
My large plunge router was very regular and straightforward to manage on the thick fences and broad slide plate, and the upspiral bit ejected mud so properly that I may rout a complete mortise with out reaching for a vacuum hose to clear chips.
As soon as your workpieces are marked and the jig is ready up, switching to a brand new workpiece and routing one other mortise takes a couple of minutes at most. The jig can accommodate workpieces as much as 3-1⁄2 in. thick, and rout mortises in a spread of sizes.
—Asa Christiana is a woodworker in Portland, Ore.
Photographs: Asa Christiana
From Superb Woodworking #291