Router Jig To Flattten Large Slabs
My jig is to help me flatten large slabs of wood to use in making benches and tables. The slab can be as large as your support rails will allow. Most of the slabs I use are 25 to 35″ wide by 5 to 6 ft long.
Linear bearings make the sled very accurate. They can be purchased on E-Bay for much less than new ones. These were$50.
I have a gunstock duplicator with very precise side rails to keep the face of my slab flat. However a good side rail can be made from 2x4's. and can be as wide and as long as you want.
I use a 3/4" straight bit to flatten the slab. You can see the router marks, but you can't feel them. A card scraper removes them in seconds.
Here's a closeup shot of the work area showing the rough slab with the freshly flattened section. I make a pass with the router, then move the sled 1/2" and make another pass.
This was the simple setup I used to see if my sled would do what I needed it to do. After using it on one slab, I bought more bearings to make my sled a little more accurate and easier to use.