My crosscut sled that I have had in my shop about as long as I have been woodworking, broke into two pieces yesterday. It was one of the first shop made things I have had since I bought my table saw. I needed to replace it ASAP.
I had scrap pieces of lumber already in my shop in order to make a replacement sled. The original was made from 1/2 Baltic Birch plywood. I selected 3/4 inch Birch 7 plies plywood that would give me a 30 by 36 inch sled. I also had some left over lumber from a sturdy sawhorse project. For that project I used some 4 by 4 Douglas Fir posts; the actual pre-milled dimensions were 3 5/8 by 3 5/8 inches.
On my jointer I milled the front fence by making sure on surface was flat and the two adjoining surfaces were square to it. For the fourth surface I sent that through my planer to get it parallel to its opposite surface.
I use Mr. William Ng’s “Five Cuts to a Perfect Crosscut Sled” mathematical method to get my crosscut front fence square to the table saw’s blade cut. My first experience with my first sled was frustrating because I was using screws to tighten down the fence to the sled’s plywood surface. The fence would move when I was attempting to screw it down, even though I was clamping the two pieces together. I drilled many pre-drilled holes that it became comical. Since then I use bolts and nuts to fasten by sled fences. The pivot bolt or location is a tight pre-drilled hole. At the other end where I will be making fence adjustments and measurements, I pre-drill a “sloppy” hole, a slightly over-sized hole so I can move the fence up or down in order to dial in a square fence. In all I use four bolts for each fence, two bolts on each side of the saw blade, for both the front and back fence. I do not care about the square fit on the back fence. It does not come into play for any lumber or board cut on this sled. The front fence does matter. I like to get it square as I can. Mr Ng’s method is the best system I have found to do that.
Intially I had planned go use a Kreg stop with a T-track. I have routed a 3/4” wide and 1/2” deep groove for this track. I haved since wondered if my fence is tall enough for this feature. My table saw can raise a 10 inch saw blade about 3 3/8 inches above the table saw table surface. I will have to measure this to be sure. However, I did measure the distance above the sled to the bottom of my groove. That distance is 3 5/16 inches. Therefore, if I place a T-track into this groove I should then limit the height of my saw blade so it will not cut into the track That seems to be a plausible alternative. Lumber that thick I usually cut at my bandsaw, anyway.
I will add material list and further instructions later.
-- --- Happy Howie