The miter gauge that comes with most table saws is fine for crosscutting narrow pieces. But if you try to use it to crosscut a wide panel, you’ll quickly discover how inadequate it is.
It rocks back and forth in the slot or bumps into the edge of the table saw top, making crosscutting not only difficult, but potentially dangerous as well.
The large, flat base of the sled provides plenty of support for wide panels. A pair of runners guides the sled and the workpiece smoothly through the saw. And a fence on the trailing edge of the sled ensures that every cut will be square.
CONSTRUCTION. To build the jig, start by cutting a piece of 3/4″-thick plywood for the base. (I made mine about 16″ x 30″.)
Next cut a hardwood runner to fit in the miter gauge slot of your table saw. Size the runner so it slides smoothly in the slot. Then glue and screw it to the bottom of the base.
To keep the jig aligned, a second runner is added to the bottom of the base. This one rides against the edge of the table saw extension wing, see photo.
Once both runners are attached, place the jig on your saw and trim off the right edge of the base.
FENCE. For the fence, I used a piece of “2-by” stock with a chamfer routed on the bottom edge for a sawdust relief, see Fig. 1a.
To position the fence so that it’s square to the blade, use a framing square, see Fig. 1. Then just screw the fence to the base.