I was running a raster engrave and everything went swimmingly for the first third. Then it just stopped. Node reported several errors:
such as “set commstate error code 31” and com 6 access denied. Then it advised that it couldn’t connect because of “no laser configured” However m5 was set as laser off command in settings.
Does anyone know whats happening here?
Usb connectors are not good for anything. Had usb connected cameras on a robot, slightest vibration and they would reenumerate. . Solder a wire on the moving/vibrating end 
There are lots of awful USB cables and connectors out there. Some few are not as bad, but not good.
Thanks, usb never occurred to me. I already changed the cable once (from a 3d printer that worked) to the shortest I could find. Any idea why smoothieboard (actual smoothieboard) is so sensitive.
@Bruce_Golling http://learnemc.com/practical-em-shielding
But if you want quick and dirty, some aluminium foil might improve it a bit, just make sure that it does not shortcut anything.