Having solved the concentric circle problem, I now have two new questions.
When the cycle starts, the router heads off to the unknown. In CamBam, I set the machining origin to the center of the circles, then in Mach3, positioned my router on the stock, zeroed out all axes, and regenerated the toolpath. The router takes off and can travel about 10" off center, then return to the original spot where I wanted the machining to start. Where am I going wrong?
Second, the router cuts the inner circle correctly, then as it proceeds outward to the larger rings, the depth of cut changes to a higher position each time it goes to the next larger ring, never reaching the -.75" I'm after. The table is pretty flat (for my first build) and the cuts are consistent around the circles, but again, consistently higher each time it moves outward. Thinking it might have something to do with the original problem, I greatly reduced the Z axis acceleration, with no luck. In fact, it seemed to decrease its ability to cut the holding tabs. The Z couldn't rise fast enough to lift over the tabs. Help!
I've attached the GCode. Your help is greatly appreciated. Thanks again,
Jeff