Fixing a Sagging Router Table Top

The router table that I use is attached to my table saw. It sits on an angle iron support attached to my Incra TSII fence system (Upgraded to LS). To the right of the table surface.

The top surface is two layers of mdf glued and screwed together, with Formica on top, bottom and 4 sides. The surface is 40” X 36.

But since it is very heavy and especially with the 3HP router hanging in the middle with a Version 1 of the Jessem Router Lift, it sages.

The table always sagged, so a while back I laminated a beam of OSB boards 3” thick and 4” wide and Pocket Screwed them to the under surface of the table top. It was OK for maybe a week or more or less.

I was at a friends this week and was telling him about the problem and he showed me his solution.

He was using a Sprung Joint Wikipedia Definition and a Fine Woodworking article on Joinery

So I took the beams off and marked the edge with a bowed line.

I then used the bandsaw to cut to the line. and then smoothed the edges with an electric hand plane.

I got 4 – 6” X 1/2” bolts, nuts and washers. I brazed the nuts to some fender washers so that I wouldn’t have to use a wrench to hold the bottom.

The brick that I’m using is a result of my looking for some fire brick. What I was looking for was some brick that is used in a fireplace. When I went to a brick MFG company and told them what I wanted he said follow me. He took me to a brick kiln that they were going to rebuild and he pulled some of their bricks that line the kiln and handed them to me. These things weigh about 6 oz apiece, very light. I liken it to the tiles on the space shuttle, they can get red hot, but the brick itself stays cool on the sides and bottom.

I got 5-6 of them and they work great.

I drilled a hole in the top surface of the router table and put the washer and bolt through that hole. I got my spacing and drilled the laminated beams. I then took the drill and realigned the holes so that the bolt would go through.

I then drilled a hole for a pocket screw to go through the washer to keep the nut from turning when I tightened the bolt on the table surface.

Here is the gap between the beam and the underside of the table top.

Turned the top over and screwed down the beams to make it flat.

I then put in the router and checked the sag. It was maybe 1/32 to 1/16”, so I tightened the bolts some more.

Very nice and flat, but just one problem The router table is just a little below the surface of the table saw so I’m going to cut some shims from some soda cans and bend the Aluminum so that I get them flush. I’ve used washers before, but never got a critical flush fit.

I’m going for the flush fit this time.

-- What happens in the workshop stays in the workshop. No wait that doesn't sound right. Karson Southern Delaware karson_morrison@bigfoot.com †