I just installed one of Kreg's precision track systems on a shop chop saw. It's a pair of extruded aluminum tracks which you mount on shop-built 3/4" thick fences, which then get fastened down to the counter tops on each side of the chop saw, in line with the chop saw's own built-in fence. An adhesive-backed measuring tape fits in a shallow recess along each track, and a pair of aluminum stops with hairline cursors allow you to quickly set the cut length for a board.
After installing the tracks I went through a painstaking process of aligning the tapes so that they would be accurate to a fraction of a gnat's ass on one specific measurement. Then I took an accurate 24-inch ruler and laid it along the tapes, checking for inaccuracies. To my dismay, I found that the tapes varied from the ruler's gradations by various small amounts, both high and low at different points, up to as high as a little over 1/32".
Now this is kind of depressing. It means that I can't depend on the cursor, but will have to treat it as an approximation and make a test cut for each new measurement. I've gotten used to trusting the 52" tape and cursor on the table saw (after initially checking it, of course), and I was hoping for the same kind of accuracy from this system.
Any of you faced and solved this problem? I've put in a support email to Kreg to see what they have to say. Maybe it's just a limitation of that kind of tape, but I'd like to hope that I could get a measurement system that I could trust to 1/64". If it was a plastic tape I'd say ok, try a metal one, but it looks like the Kreg tapes are metal. And searching on the web turns up a ton of adhesive-backed tapes, but hasn't shown me anyone who makes any specific claims about the accuracy of their product.
Comments? Thoughts?
Tom