Alright, got it figured out.
I guess outputs 1 and 4 have to be on to run the spindle. When I run a sbp file it turns 4 on, and I guess I need my CAM software to turn number 1 on. Apparently Partworks has this built into the post-processor. I'm using MasterCam X3 as my CAD/CAM and will have to do some research into the PP.

For now, my guys have to turn on output 1 (alt+1), then load the file (FP) - a small annoyance, but not the end of the world.


Does anyone have any experience with the MasterCam post-processor? I haven't searched the forum yet, but any advice would certainly be welcome. Thanks all.