Here: http://blog.inventables.com/2014/06/shapeoko-upgrade-quite-cut-spindle-with.html it says "Wires from gShield to relay. Red is +5VDC, yellow is signal wire from D12, green is ground. "
But in the instructions: http://x-carve-instructions.inventables.com/step14/ the Z axis limit switch is in D12.
What am I supposed to do? Is the spindle supposed to shut off when it reaches the limit?