As mentioned in prior postings (beginning on 30 May 2005), I have a Wilton 8201 metal-cutting bandsaw, and was having problems getting straight and square cuts. As a test, I made a small (6x9") sled from scrap metal that happened to be in the shop, and the sled worked. So, a larger sled was planned. It has now been built and tested.
The larger sled is 5/16 by 7.75 by 13 inches 6061 T6 aluminum, with a
23" cold-rolled steel 3/8 by 3/4" rail screwed to it. The rail rides in the mitre gauge slot of the bandsaw table, and has two 1-3/8" steel knobs screwed to it, one at each end. Perpendicular to the steel rail is an aluminum rail against which the stock to be cut is held. There are two toggle clamps reaching over the aluminum rail that clamp the stock to the 7.75x13 plate.This almost worked. There was a residual error of 0.015" in 7.5935" (the width of a test plate), or 0.11 degrees. I figured that one or the other rail had shifted when removed and replaced, as flathead screws are not *that* accurate. So, I added dowel pins, the holes being drilled and reamed through both plate and rail while clamped up to some import
1-2-3 blocks. No dice - still more or less the same error. Perhaps one of the blocks is crooked; I have no easy way to detect this. (Hmm. I do have a way, but didn't think of it at the time.) Or I made some mistake. (The clamping setup was awkward because the 1-2-3 blocks could not be bolted together for lack of clearance holes for 3/8-16 studs.)So, I added a second aluminum rail screwed to the first, allowing me to shim the second rail such as to get a perpendicular cut. This worked. So far, I've cut up to 1/2-inch aluminum plate.
Joe Gwinn.