This is a 45 Degree Miter Sled for my Rigid 4512 table saw. I was having some trouble getting the stock miter guage 45 degree stop set correctly when I saw this on Rockler. http://www.rockler.com/45-degree-miter-sled I was about to go buy this when I thought. Hey, I have a 3D printer. I designed this sled so you can attach a piece of extruded aluminum to increase the pushing surface area and attach hold down fixtures or stop blocks. Here is a video showing how nicely it moves. http://youtu.be/kJW6jf0wPiw Now I am thinking about doing another one for by cross-cuts.
I made it at .28mm layer height 100% infill. I used 1/4"x1" zinc hex screws, 1/4" hex nuts, and a 1/4" washer, 1/4" lock washer. I also used 3 x M5x16 button head socket screws and 3 x M5 nuts. Any aluminum extrusion should work. I purchased this from Rockler.