Wanhao i3 Plus - one Z stepper doesnt stop on homing



Hi guys

I’m a new member with a doozey of a problem

Sometimes when homing, the right hand Z stepper doesn’t stop when the left hand motor hits the end stop micro switch. The left hand z stepper stops perfectly every time

You can hear the left stepper click and stop as it should, but not the right hand. The right side of the gantry just keeps going down !- eventually hitting the print plate and causing all sorts of damage

- Before this happens z gantry is calibrated and parallel to the build plate

- build plate has been levelled.

- this is not a bed levelling issue.

- There is no jamming occurring, its almost like the right z stepper doesn’t get the ‘stop’ signal

- It only occurs say 1 in 10 times i try to home when setting up a print

- Apart from that , the printer is working pretty well

- I have opened up the box and all plugs etc seem to be seated properly.

Help help help !