I'm building an odd-shaped box which has two 4-sided cleats beveled on the top with ends angled such that the top is a nice rectangle to mate with the top piece - it's easier to sketch than describe.
On my table saw I beveled the blade and ripped the top off @ 6.5 degrees, ripped a few shims at the same angle, and used those shims between the piece and miter gauge/table to cut the ends perpindicular to the sloped top with the blade straight up.
If I had the foresight to flatten the opposite side of the shims and cut all the pieces at 6.5 degrees without changing the bevel inbetween I'd have perfect cleats that needed no planing or sanding.
After the fact I realized that I could have used trigonometry to determine miter and bevel angles which yielded the same cut.
1) What sort of accuracy would I gain or loose with that?
2) Is there an excel spreadsheet or java calculator out there so I don't have to think about the calculations?