Z axis opto switch calibration

[spiyda]

I just changed the opto switch on my other machine and found a way of setting the position that seems to work ( on the RV4s at least)

( part number Omron EE-SA105    Mouser   653-EE-SA105 )

run the armtest program on the pc ( no need to have the main power on)

lift the "Z" axis until the number showing for "Analog 2" starts to change ( the mirror will flip down)

estimate the thickness packer you need between the mirror follower bearing and cam shaped lump of the Z axis it runs on to keep it in that position  ( on mine a bit of 1.6mm FR4 worked a treat, but this may vary  )

add just a little more packing and the "Z" axis should sit there with the "Analog 2" readout showing something between 10 and 255

Now you can remove the opto switch and fit the new one.. adjust it til the number reads the same as before.

Job done, time for a cup of tea !