I’ve never been a fan of any jig that requires a degree from the Massachusetts Institute of Technology to build or use. So the Jig Journal column is a perfect fit for my shop jigs. This month’s offering is a jig that has carried many of my furniture parts over the past 15 years – a panel-cutting sled. For a short video showing me using this sled, click here to go directly to our video site.
Three Parts to Square Panels
This jig is made up of three parts, all of which can likely be found in your scrap bin. The major player is the panel ( 3/4″ x 18″ x 24″) that carries the workpiece. Attached to that panel is a straightedge fence ( 7/8″ x 7/8″ x 36″) running perpendicular to the blade and a guide ( 3/8″ x 3/4″ x 27″) that runs in the miter-gauge slot of the table saw. It’s best to use quartersawn hardwood for the fence and guide. Small pieces of plywood tend to delaminate – or if you hit a void it’s trouble.
However, plywood is the best choice for the panel. There’s greater stability in plywood over a hardwood panel, because there is no seasonal movement. And plywood is better than MDF because it’s tougher to ding as you move it around the shop and it’s more resistant to moisture.
To locate the guide bar, measure the distance from the right edge of the left-hand miter-gauge slot to the saw blade, then add 1/4″ – this jig rides to the left of the blade. Once the guide bar is attached, the additional 1/4″ allows you to trim a straight edge that’s aligned with the table-saw blade.
Transfer that distance to the underside of the panel. Hold one end of the guide bar flush with the leading edge of the panel as shown in the center picture atop the next page, and attach the 3/8″-thick hardwood, snugly fit to the saw’s slot, with four #6 x 1/2″ flathead wood screws. The guide bar attaches at the line, away from the blade.
By allowing the guide to extend beyond the back edge of the panel (the edge nearest the operator), you gain additional panel-cutting width. But don’t go overboard. You need to have the majority of the panel resting on your saw’s top after the cut is complete. Push too far and the sled tumbles off the saw.
Place the guide bar into the saw slot so it’s well behind the saw blade. Start the saw and push the sled into the blade. The edge of the sled’s panel is now parallel to the guide and the saw blade.
Squaring the Important Piece
Aligning the sled’s fence is the most important step in building the jig. To accurately set the fence, use geometry. The calculation is a 3-4-5 triangle. Using multiples of three and four for the two legs sets any right triangle. Then, the hypotenuse is a multiple of five.