Yet another table saw sled

I've seen some pretty over-the-top, over-wrought ways of cutting an accurate 45 degree angle. It doesn't have to be that way. In fact, it really shouldn't. Your energy should be spent on building things that are useful in a context other than just your shop. Furniture, screen doors, whatever. But you should still focus on accuracy when you can.

This one took about an hour and a half to build, including clean-up.

First step was fitting the Ipé rail to the miter slot in the saw table. I used the micro-adjuster on the fence for this, to get a good, close fit. I also used it to trim the sides of the dado in the MDF to fit. When you can reliably adjust the fence by .002", it's easier the adjust the fence than to mess with shims for a single dado.

(truth be told, I was too lazy to pull out the dado set. 6 passes with the saw blade cuts 3/4" just fine, plus fine tuning to fit the rail.)

Once the rail is in, I put the sled on the table saw, rail in the miter slot, and trimmed the left edge to get my reference edge. (The distance from the edge of the plywood to the edge of the dado is slightly more than the distance from the slot in the saw table to the blade, so that a zero-clearance fit can be made with this trimming step.)

The fences for the sled are pre-drilled, and the holes are counter-sunk on the under-side. Why? MDF doesn't stay flat when you drill into it, it deforms upward around the screw, making a lump that will prevent the fence from settling all the way down onto the sled floor's surface, and gluing up properly. You could screw it down, take the screws out, and re-flatten the surface, I suppose, but this is faster and easier, and doesn't depend on the MDF holding the second set of threads.

Glue is smeared on the underside of the fence, which is then put down. First screw goes in at the business end of the fence. Then you fine-tune the 45, then drive a screw down at the other end. Check the angle again. If it's off, take that second screw out, adjust the fence, and put another screw into a different hole to fix the position. Then drive the rest of the screws, driving that 'off-angle' screw last. Be as precise as you can about getting the 45 as close as you can... it's the whole purpose of the sled, and the only critical step that will really make or break this project.

Repeat for second fence.

I used brass inserts in the fences so I could bolt down the toggle clamps. It's just easier than holding the work down by hand.