pic: Rough matches out there.

[JesseK]

Originally Posted by BBray_T1296

We use an aluminum cutting circular saw blade on a miter saw to slice our tubing (I think it is a $120ish blade). We used 1x1x1/16" and 1x2x1/8" tubing to build our frame.
We also use some cool corner stiffener inserts to keep the whole thing square. Our tolerances come to 1/32" with our most experienced student at work. The welding gives us the most tolerance troubles, but we are less than 1/16" everywhere

We use a horizontal bandsaw with automatic shutoff and plenty of cutting fluid to cut the pieces to near-perfect length. Then we tape all same-length frame members together so that they're flush on one end, and go to a wide belt sander. We sand one side of the taped tubes so it's square and the other side is sanded down so that all tubes are identical lengths. This year I think we were under 1/32" off, or basically less than a single tick of the tape measure. We then adjust CAD if necessary. We've become better at tolerances, so usually no CAD adjustment is necessary. While the welds have never been perfect (the rails always warp just a tiny bit) they're much better than we used to do.

I should have put that the waterjet/CNC was to cut mount holes & pockets into the 4x2 since it's so heavy.