Now that the design is complete, it’s time to make some man glitter, otherwise known as sawdust. The next two posts will be a step by step guide to building the sled. The first installment reviews building the sled base, and the second covers the remainder of the build.
Mill the removable zero clearance plate
Begin building the sled by milling the zero clearance plate. Though you won’t install the plate until the end of the build, you’ll use it as a reference while building the rest of the sled.
I started by cutting some tigerwood into sections. I’m milling five plates so I have spares milled using the same setup. Why tigerwood? It’s dense, stable and I’ve been tripping over a 14 foot piece leftover from my deck build for the past four years.
Using the jointer, flatten one face of each board, then flatten an edge. These are your reference surfaces.
Keeping the reference surfaces against the fence and the table saw top, rip the plate to width.
Use a thickness planer to mill the plates to the thickness of the plywood sled base top pieces. Be sure to keep the reference face against the planer bed. It’s better to err on the side of thinner. You can fine tune the plate by shimming it with masking tape which is around 0.005” thick. If the plate is too thick and stands proud of the sled’s surface, your stock will rock on the plate. I’m using 1/2” plywood to keep the weight of the sled down, so I’ll mill the plate to match.
Laminate the fences.
Cut the pieces for the front and rear fences from 3/4″ plywood. I mistakenly used 18mm plywood and had to dado the tops of the fences to accept a 3/4″ T-track without it standing proud of the fence’s face.
Use the zero clearance plate to create the corresponding gap in each fence during glue-up. Once the fence is clamped, remove the plate so glue squeeze out doesn’t adhere it to the fence.
Clamp the face of the rear fence to known flat working surface. As you can see in the photo, I didn’t clamp the rear fence to a flat surface. The two faces were not coplanar after glue up. Luckily, a quick pass through the planer fixed it. If you don’t have a flat surface, clamp the fence to a rigid straight edge such as a long bubble level. The flatness of your rear fence glue-up will determine the accuracy of the sled later.
Laminate the base
Cut the three base parts from your sheet of plywood. The more accurately you cut them to square, the easier the fine tuning will go later.
Test fit the assembly by clamping the fence or a straightedge to the lower base with the front edge 1-1/2” from the rear edge of the lower base. Lay the left and right upper base pieces on the lower base. While squeezing the zero clearance plate between the two upper base pieces, pull them rearward against the straightedge. If everything is cut squarely, the upper base pieces should touch both the straightedge and the zero clearance plate, and the plate will be perpendicular to the rear of the base.
Lay the base on a flat surface and glue up the assembly. if you don’t have cauls and clamps large enough, lay some heavy weights on the base to maintain flatness and clamping force. You can use a brad nailer to keep the upper pieces from moving. Take out the zero clearance plate and straightedge to be sure any glue squeeze out does not adhere them to the base.
Machine the fences
Once the fences are dry, flatten the bottom of each on the jointer to be sure they are square to their respective faces.
Cut the sawdust relief groove and the T-track dado on the face of the front fence using the table saw.
Drill the indexing holes in the fence on the drill press. Drill a test hole in a piece of scrap first to validate the press fit of the inserts.
To improve the accuracy of the hole pattern, clamp a board to the drill press table and reference the bottom of the fence against the board. I made the mistake of referencing the top of the fence. Though it came out fine, you should always use the reference surfaces when possible.
Drill holes for the zero clearance plate retaining clamp and slot them using the band saw or a hand saw.
Shape the corners of the front fence on a band saw or belt sander. Ease the edges of both fences and sand them smooth.
Install the fence hardware
The T-Track can be cut on a miter saw or with a hacksaw. I chose the hacksaw because it makes less of a mess. The hacksaw cuts through aluminum quickly and leaves fine dust in a small pile. The miter saw is faster but sends large chips flying.
Clean up any sharp edges of the T-track with a disc sander or a file and install them on the fences.
Press the inserts into the rear fence ensuring they do not stand proud of the face of the fence. This is another place when using 18mm plywood bit me. I had to cut each insert shorter because the fence was not the full 1-1/2” thick and the inserts stuck out of the back side of the fence by almost 1/8”.
Up next are the steps for finishing the sled build. The final installment, part 5, will cover fine tuning the sled.
