Difficulties in probing

It should travel down fast (Setup Speed) until probe height is reached, then it should travel down slow (Probe Speed) until the switch is tripped, then it should move up very slow until the switch is off and then move up fast (Setup Speed) to Pierce Height.

If it trips the float float switch before it has moved down to probe height then it will move up until the float switch if off then it will move down at Probe Speed and follow the sequence above.

It you are tripping it by hand before probe height then you need to do trip it again after it begins moving down at Probe Speed.

Probe Height is the height above the Z axis minimum limit (not the height above the slats), it is usually set to just above the highest material that you will cut.

Can you post your current config and I will make a sim and test it.
 

Something doesn't look right with your earlier posted Z axis settings.

Can you confirm that when you jog Z plus that the Z axis moves up and when you jog Z minus it moves down.

Yes it is a bit backwards.

You need have AXIS_Z MAX LIMIT and JOINT_3 MAX_LIMIT the same 70? (or 100)?
set the following JOINT_3 paramaters:
STEP_SCALE = -200.0 (negative will reverse the motor direction so it is correct)
HOME = 65 (or 95)
HOME_OFFSET = (72 or 102)
HOME_SEARCH_VEL = 20.000000
HOME_LATCH_VEL = 1.000000
HOME_FINAL_VEL = 10.000000

EDIT: Here is a diagram of a Z axis (we should add it to the PlasmaC docs):

linuxcnc.org/docs/devel/html/plasma/qtpl...tml#qt_initial-setup

 

No worries, sorry it took me so long to see the error ...
 

Sorry I never saw the issue