A plunge router is great forcutting mortises on the edgeof a workpiece. The only trickis getting it centered. Here's ahandy auxiliary base that willcenter the bit automatically,and it works with workpiecesof just about any thickness.

The key is a couple of pins.These are nothing more thancommon bolts with theirheads cut off. I fastened themto the base with T-nuts andhex nuts, but for the base towork, these pins have to bepositioned carefully. The centerpoint of the bolts and the router bit must form astraight line. Plus, the pins must be the same distance away from the bit.

To use the base, simply attach your router and set the base on the edge of the work-piece. Twisting the base so the pins contact each face of the piece automatically cen-ters the bit, as you can see in the details at bottom right. Then just plunge and routthe mortise.

© 2006 August Home Publishing Company. All rights reserved.

Self-Centering Plunge Router Base

Router Techniques

TOP VIEW END VIEW

SHOP-TESTEDTIPS & TECHNIQUES