I've built a 45 sled. nothing to it really... Like mentioned above, its really nothing more than a std. sled with a 45* bevel as the primary cut. Mine is a smallish version, works
quite well on small projects. It's only about 12"x14" or there abouts. When I redo it, I'll make it considerably wider (left to right) to have better control over longer boards. For now, anything that is 18"-24"'s balances out well on the sled. Anything boards longer and I have to put more effort than I care to on keeping the board flat on the sled as it
passes thru the blade. I also plan on putting in a "T" track on the left side to aid in clamping down the work piece...