Conejo Valley Woodworkers Association
Guide to Jigs and Fixtures
June 2004 Supplement to the Bladerunner

Jig: Sliding Taper Fence Reference: #002
Presenter: Tim Albers Used with:Drill Press
Full resolution images are available by clicking on the embedded images.

The sliding taper fence is a useful accessory for the drill press and hollow chisel mortiser. It can also be helpful when used with the bandsaw when small precise parts must be cut. The principle behind this fence is that the back or stationary part of the fence can be clamped or bolted down to the table and the front of the fence slides sideways, moving the fence either towards or away from the cutting tool.

The fence is simply two right triangles with the same angles; so when they slide along their hypotenuses the long sides remain parallel to each other.

This jig is best made from cabinet grade plywood or a similar stable dense material. Avoid MDF, as the edges donÕt hold up well to repeated use. To construct the jig, first start with material of uniform thickness, youÕll need two fence pieces, each approximately 2" wide by about 24" long. YouÕll also need three narrow support blocks and three tapered pieces, one of these should be about 1 ¼" wider than the other two.

The jig can be made to any length necessary. IÕve found that a 20" to 24" length is good for a drill press and a 12" fence is ideal for use on the bandsaw. In addition, the angle of the taper can be almost anything up to about 25 degrees. A smaller angle yields a finer degree of adjustment.

After cutting the tapered pieces, route a long slot parallel to the taper (hypotenuse) on the widest piece. Next glue and screw this piece to one of the other tapered pieces. Glue and screw this assembly to the front fence. Next attach two narrow support blocks to the underside of the rear tapered piece and attach the third block to the top of the tapered piece. If the jig will be used on a drill press the rear fence is not necessary (as shown in the photo below). Finally drill two holes in the rear assembly to accept two threaded inserts for securing the two assemblies together.

The front fence can be customized to any application necessary. When completed a liberal coating of wax will keep the jig operating smoothly.