by cvoinescu » Tue Jun 11, 2013 4:38 pm
Check your limit switches. If they're wired incorrectly, or the configuration doesn't match the wiring, all sorts of weird things will happen. Use M119 to see the status that the board sees. Issue that command while pressing and releasing each switch, and check the results. Check that they are assigned to the correct pins in config.h. If not using the limit switches yet, it's important that you disable them in config.h -- set them to (-1). Actually, it would be a good idea to start with all limit switches disabled, just to eliminate them as a possible cause. Once the machine jogs the way you expect it, you can configure the limit switches, knowing that any weird behaviour is because of them.