Thought I'd pass along a little trick that utilizes the "built-in" flex of the gantry and all things attached.

First cut I made on the shopbot was a square, cut full depth single pass in conventional direction; the part was undersized. So I cut it in climb; part was oversized. Next I try two passes, second pass removing .050" thickness. In conventional, I've got a .020" or so step all the way around my part, and the majority of the cut is still undersized; But AHA! I notice that on the waste side, the cut is beatiful. Hmm, so I try climb cut. The step moves to the waste, and the good side is on the part, but some of the wood I cut doesn't like climb cut.

So my solution, cut climb to about .050" above the table, then cut conventional full depth plus whatever you dive into your spoiler, I go .005". Since doing this, I've never had to fight with the allowances. The cutter and gantry flex force the bit away from the part on the first go round (experience shows about .020") then the second cut in the conventional direction cleans it up right to spec.

Tool pathing in Insignia is easy, after the climb cut, just type in a new name at the bottom, change to conventional and increase the depth accordingly.

Of course, YMMV, yada yada. Works for me though.

Gabe Pari
www.socalteardrops.com