Ender 3 NG v1.2 two-screw Y endstop

When homing, the Y gantry hits the Y endstop microswitch.  This endstop has a tendency to come loose and twist, especially in a heated chamber.  When this happens, the Y will calibrate at a further distance than intended.  Probes typically live on the back of the toolhead, and this added distance can make the probe collide with the Z rod mount and break the probe.

This improved design adds another mount screw to the Y endstop mount.  This solves the twisting problem, and gives the Y endstop a little more grip on the aluminum extrusion.

Y endstop with two screws (instead of one)