I purchased a new Jet "Supersaw" complete with 52 inch rail, table extension, and sliding table about a month ago. One of the primary attractions of this saw was the sliding table. I've never felt it worked as well as expected. Though its heavy and slides smoothly, it did not seem to line up with the blade properly. When I did a cross cut, the blade would cut deeper into the wood, as it moved into the rear teeth of the blade. This is a symptom of the table not sliding parallel to the blade. I had already had the dealer check blade alignment with the right side miter slot and it was dead on. The sliding table alignment is pretty idiot proof. They give you some .020 shim stock to place between the sliding table and the main saw table. You just butt the two together and tighten up four bolts. If the left side of the main saw table is parallel with the saw blade, the sliding table should move parallel.
Well, that last statement is a big assumption. I adjusted and tweaked and measured until I was blue in the face. Then I decided to check what I assumed was ok - the left edge of the main saw table. Boy was I in for a shock. I almost purchased a dial guage and fancy clamp just to accurately measure how closely things were aligned. But then I thought - "This is silly". Instead of that, I bought set of good ol' feeler guages and used my combination square. I discovered the sliding table was about 0.029" difference between the front and back side of the blade! Jet's maximum tolerance is 0.0118" for blade parallelism. I have not gone back to Jet technical service yet. They told me that this was a simple tuning problem and walked me through the procedure for aligning things (the ol' mark the saw tooth and measure against the same tooth front and rear).
I'm convinced that this is a manufacturing defect. Its as if the left side of the table never received a final machining. I did some gross measurements using a combination square and took some pictures to illustrate the problem. Admittedly, you cannot measure thousandth's of an inch with a cheap combination square, but it does hold a constant measurement when locked and relative measurement is what we are interested in. My pictures are at
Bob