The problem with using a router for trimming hardwood edging on plywood is keeping it stable during the cut. Balancing the router’s base on the narrow edge of the workpiece is always a little tricky. To overcome this problem, I made a jig for my palm router. With a flush trim bit installed in the router, the jig provides a stable platform to ride along the face of the shelf instead of the edging.
After drilling an oversized hole for the bit in a hardwood blank for the base, I chiseled out the waste to form an opening for chip removal. A rabbet cut on one end of the base creates a channel for the uncut edging. Another hardwood block is glued to the base and forms the handle.
Finally, attach the router’s edge guide with machine screws and wingnuts. Adjust the position of the guide so the cutting edge of the bit is flush with the base of the jig.