The Woodshop Shed

Router table fence and router lift installation with accurate radius corners

Furnished content.
(from Lumberjocks.com)


The last projects for my new Sawstop tablesaw were to install a router lift and build a detachable fence. I previously built an outfeed table and added adjustable legs, documented in a previous post.The fence was a design that's seen often. I made mine with 1/2 Russian plywood, added an enclosed opening with a dust port for my shop vac, T-track for feather boards, and a split fence made from black Melamine to accommodate different size bits.The router lift I decided to buy was the Jessem Mast-R-Lift. It's well rated and will accommodate different sized routers if I decide to buy a larger router in the future. The challenge for the installation was the 3/4 radius of the corners, since I wanted a very clean installation. Some plates have a 1/4 radius, so the usual technique is to attach pieces of wood around the plate to build a frame and use a 1/2 diameter flush trim bit to rout the recess. If I were to use this technique, I would need to buy an expensive, seldom used 1 1/2 flush trim bit to make the radius accurate.I found an old forum post that referenced using guide bushings and making 2 templates, but the details were a bit vague. I liked the concept, so after some thought came up with the correct formulas to make a perfect template. I'm sure others have done this, I just haven't seen it explained before. Here's what I did:A first template was made by attaching the plate with double stick tape to the template material (I used 1/2 mdf) and routing around the perimeter with a 1/4 straight bit and a 1/2 bushing. This leaves an opening that is 3/8 larger on all sides. You might have a few spots that need filling with wood filler and sanded smooth.A second template is made by attaching the first template to another piece of mdf with double stick tape and routing the interior with the same 1/4 bit, but switching to a 1 bushing. This produces a perfect match to the router plate. It may sound counter-intuitive, but the formulas explain the math.
Template 1 (routing outside the perimeter): 1/2 bushing OD + 1/2 bit diameter = offset (3/8)
Template 2 (routing inside the perimeter): 1/2 bushing OD – 1/2 bit diameter = offset (3/8)You can use different size bits and bushings, just size them accordingly. Once the final template was made, I attached it with tape to the extension wing of my saw and used a flush trim bit set slightly deeper than the plate thickness. Size of the bit doesn't matter as long as it's smaller in radius than the corner. I then added some spacers inside the template and used a straight bit to cut the opening for the router. Final steps were to strengthen the particle board with super glue, and add a solid wood frame for reinforcement under the table.I hope that someone else finds this useful. I enjoy the problem solving aspects of woodworking, and I think I can use this knowledge for future projects.

0 comment(s)