ARTICLES & REVIEWS

A friend recently complained that his Hitachi M12V didn't have a large enough throat to accommodate the larger horizontal panel raising bits. It's a simple process to cut the offending template bushing ears off but what if you wanted to use a template bushing after removing these ears? Rather than try to explain my remedy for this obstacle over the phone I decided to put it in picture form. I hope that it helps others who may have the same issues.

It's a simple process to remove the template bushing ears; I removed mine by simply cutting them off with a jig saw and a metal blade. Of course the base assembly was removed from the router first.

One must be careful not to remove too much material in this area and compromise the structural integrity of the router base. Careful machining and sanding results in a nice clean opening.

With the ears removed I can now concentrate on making a new base plate for the router that will hold the template bushing. By the way, I like to use the industry standard 1 3/8" Porter-Cable type template bushing and I prefer the brass bushings—brass nuts won't unscrew when installed finger tight.

My new base plate material is a piece of ¼" Lexan® that was laying around the shop and is perfect for this—it wears well, is easy to machine with woodworking tools, and is almost bullet proof (really—in thicker dimensions, it is used to make bullet proof "glass". ed.). The original base plate was removed from the router and clamped onto the new blank in order to accurately drill the mounting holes; care must be taken here when drilling these holes to assure a perfect fit to the router base.

Once the holes are drilled, and while it's all clamped together, trace the footprint of the original base plate onto the new blank to be cut out later. Then remove the original base pattern, flip the blank over, and countersink the holes that were just drilled to accommodate the original base screws.

Install the newly drilled blank on the router and insert a ¼" spiral bit into the collet. I've chosen this size bit because it matches the pilot drill bit in the mandrel of my holesaw—the purpose will become clear below. The spiral bit is plunged through the Lexan® and then the blank is removed from the router.

Place the blank on the drill press table bottom side —the surface with the countersinks— up. Chuck up a 1 3/16" holesaw which is the size of the shank of Porter-Cable type template bushings and will be used to make the through hole in the blank. Line up the ¼" pilot bit in the mandrel of the holesaw with the ¼" hole that was plunged by the router, clamp the Lexan® blank securely to the drill press table, and cut the hole all the way through.

The bottom side up orientation is necessary for the proper location of the counterbore which will be drilled in the next step. Do not remove the Lexan® blank until the next step is completed.

Without disturbing the setup, remove the holesaw from the drill press chuck and replace it with a 1 3/8" Forstner bit. The Forstner bit will provide a very clean and accurate counterbore for the template bushing to fit into. Care must be taken to drill this hole to the right depth—we're looking for the bushing to sit just shy of the surface of the Lexan®.

From start to finish attention to careful machining will yield this as a result. Because we used the router itself to index the pilot for the holesaw the router bit is exactly centered in the opening.

All in all, this is just one way of solving the problem of using large router bits in a router that doesn't have a large factory opening and still being able to do template routing. The tools that were required were few and found in almost every woodworking shop. What you may not have doesn't cost very much to procure and probably needs to be in your shop eventually anyway. Hope this helps.

^© 2004 by Gord Graff . All rights reserved.
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