So I've been saying for some time I wasn't having much luck printing over USB w/ S3D. I figured out a HUGE thing that was deterring me and thought I'd share.
Machine: Flashforge Creator X but probably this applies to lots of x3g clones/machines.
Problem. I'd go to the control panel and select to move the platform down w/ jog controls but the result would be it would move the platform as well as ram the extruders into a wall or something. I always just figured they didn't have things all the way ironed out with usb communication and just printed from SD card instead.
Root cause: The jog controls don't set the toolhead.
Background is I have two extruders. So if I happened to be using the left extruder (which I do all the time... support material in the right one, main plastic in the left.), the toolhead would be set to 1. But since the z-axis is on Toolhead 0 when I'd use the jog controls it would move the extruder as well as the platform.
Workaround: manually set the toolhead back to 0 before attempting to move the platform. You can do this by selecting the toolhead above the temperature panel.
Anyway, thought I'd share in case anyone else is scratching their head on why they can't control things correctly.