Most people use 3 endstops. one per axis
They are miss named, they are homing switches, not really endstops
They can be either at min or max end of travel, most people put them at min position as max position just confuses most people far to much
Be careful of these endstop with 3 wires... if you plug those in backwards you kill voltage regulator on your controller. (as you short +5v to gnd)
