Synopsis: This design is aimed at improving the traditional crosscut sled with a two-layered base and sliding panels that let you refresh the zero-clearance kerf around any blade or stack of blades, angled or square. A replaceable insert plate in the front fence serves the same purpose.
Soon after I began teaching woodworking at Palomar College in southern California, I knew we needed a more reliable method for clean, accurate crosscuts. Our miter gauges and beat-up crosscut sleds just weren’t cutting it.
I considered the traditional crosscut sled design and thought we could do better. Standard sleds start out with a clean slot in the base and fence, which fits perfectly around the blade that cut it, preventing splintery blowout on the back and bottom edges of cuts. The zero-clearance blade slot also shows you exactly where the blade will cut, making it easy to hit your pencil mark perfectly. But that clean kerf doesn’t last long. The moment you change the blade, angle it, or worse yet, use a stack of dado blades, the slot gets blown out—and its zero-clearance benefits along with it.
Rethinking the traditional sled, I designed a two-layered base with sliding top panels that let you refresh the zero-clearance kerf around any blade or any stack of blades, angled or square. In the front fence, a replaceable insert plate serves the same purpose.
While I was at it, I addressed the other common problems with traditional sleds, such as sloppy runners and bowed fences. After six years of heavy use, the six sleds I made are just as accurate and effective as the day I built them.
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G10 vs. phenolic plywood for the base
I used a lesser-known sheet material, a fiberglass-resin composite called G10, for the structural base of my sleds. The fiberglass layers in G10 create an incredibly strong, stable, flat panel, allowing me to make the base just 3/8 in. thick. It slides beautifully too. However, at $250 for a 3-ft. by 4-ft. sheet—the smallest available size that would work—G10 is very expensive. It also beats up standard woodworking blades and bits. While it made sense for our college woodworking shop, it’s probably overkill for a home shop.
A reasonable alternative for the base is phenolic plywood, which delivers the strength and durability you’ll need and is both affordable and widely available ($43 at woodcraft.com for the 24-in. by 32-in. piece I used here). The surfaces of this specialty plywood are infused with phenolic resin, which makes it slide beautifully and protects the interior from changes in humidity, making the panel more stable than standard plywood of the same thickness. It’s not G10 though, so I bumped up the thickness of the base to 1/2 in. Add the sliding 3/8-in.-thick MDF panels on top, and you still aren’t stealing too much from the height capacity of your saw.
A quick tour of your next sled
The design starts with the two-layered base. The sliding MDF panels are held down with screws that pass into threaded inserts in the base, ensuring a durable hold. Down the road, after you’ve repositioned the sacrificial panels a number of times, and made them too narrow, it’s quick and easy to remake them, and the fixed, structural base of the sled never changes.
To allow the blade slot in the front fence to be renewed just as easily, there’s a 3/8-in. MDF plate set into it. This fence insert is attached with screws and threaded inserts. In fact, at every attachment point, from the fences to the insert to the sliding panels, I used machine screws and threaded inserts. Standard wood screws strip when tightened and retightened; threaded inserts will give a lifetime of service.
Chance Coalter teaches woodworking at Palomar College in San Marcos, Calif., and builds furniture on commission.
Photos: Asa Christiana
From Fine Woodworking #300
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