Currently, there’s a focus Z button on the “Move” panel but no Home Z for Ruida controllers. Focus Z seeks the Z limit switch on my machine and then drops down for an unknown duration. Is it seeking Max Travel? My bed goes deep so I don’t want to bottom it out. I used the home Z on the RDWorks software to get the Z zeroed but I don’t see a way to do that in LB.
Focus Z is waiting for the focus probe to hit the surface of the material. If you don’t have one, that would be the problem there. For the Z-home, I don’t have that button yet - I assumed that if you had a motorized Z you’d home it on startup like the other axis. I’ll make a note to add it.
My laser has no focus probes as far as I can see, yet it still focus automatically within maybe 0.2 mm or so. I have no idea how it works, I see no sensor of any kind. No mechanical switch, no optical sensors. All I see is the laser, and a red pointer for aiming. Magic or aliens?
With the laser, I also got a small plastic gauge for focusing, and the results of the autofocus seems the match it well.
I have an older laser cutter that uses a proximity switch on the laser head. Placing a metal fob on the material will initiate a z-limit signal when it gets close enough. A Z-home button would be welcome in my setup. Thank you.
What is the make of your laser, and could you take a picture of your laser head and post it? You have me curious as to how they are doing it. My bet is aliens 
I’m off to work, so no time for pictures now, but it’s this model (and there are plenty of pictures at that link): https://www.aliexpress.com/item/Free-shipping-HCZ-RFE-130W-CO2-laser-cnc-DPS-1060-laser-engraving-cutter-machine-marking-machine/32935221043.html?spm=a2g0s.9042311.0.0.559f4c4dq09VM3
Are there any wires going to your head besides the air supply?
Just power for the pointer.
Does the table set to the head at any position or just bring the table up to a limit switch that you cannot see? Mine is on the right side of the table.
It does not move the head.
I’ll check for a limit switch when I get home. I don’t think that’s what it does, though, as it seems to take material thickness into account.