Z- End Stop strange behaviour

I have been using my K8200 for some time and it has been printing ok.
(I’d like to get it printing better)
I have done various upgrades (improved Z-Axis, end stop screw etc)

I have been working on implementing the z-probe for auto-bed levelling using the capacitance sensor.
thingiverse.com/thing:447719
I have built the circuit off line and the sensor does in fact trigger by pretty much any surface at pretty much 1mm

However when looking at how my CURRENT z-end stop switch works I was surprised by its behaviour

When I move the Z-axis using host software it moves up and down fine
However when the Z-axis is moving down (under motor control) if I manually trigger the z-end stop switch shouldn’t the z-axis stop immediately
That is how the x and Y axis work.

When the z-axis moves down to the zend stop switch it triggers fine and I have no issue printing (is manually triggering that does not work).

In order to debug I have disconnected the z-end stop switch from the controller board and checked the switch operation with a continuity tester and it works fine (normally on and goes open when triggered)
I have checked the board as well and it has 0 and 5v on the relevant pins where the z-end stop switch is connected

I can’t understand why I am seeing the behaviour I am but still being able to print with out an issue as the switch definitely appears to be triggering the z-axis to stop when it gets to the heated bed - if it wasn’t working I would see the nozzle head crash into the bed.

Obviously I am missing something (probably very simple !!!)

Anybody able to throw light on this

tks
Noel

Hi, if your are using V2 of the firmware, endstops are only enabled for homing. This was implemented to stop false endstops (due to vibration etc) causing a print to stop. Not much fun if you are in the middle of a 10 hour print. It is a requirment for the auto leveling as you will see that the sensor is triggered for most of the first layer.
Try raising up your extruder and then “home” instead of “move to” and the endstop should stop the travel.
G28, G29 & some others use endstops, G0 & G1 dont use endstops.