Z-probe Height vs Max z-probe bed dist in EEPROM Setting

briankb

I think I have my Prusa i3 z-probe setup correctly except for it actually getting close enough to the bed. When I do manual z-probe it moves away according to the z-probe offset for x and y and then returns the nozzle to the position. very cool! but I cannot seem to get it to go down to the bed. 

With the mechanical z-axis end stops you can just move it up or down until it is perfect. How do you do this for the z-probe? I assume it has something to do with Z-probe height and Max. z-probe - bed dist. but I'm unclear what those settings in the EEPROM actually mean as related to the bed to nozzle height. 

What does the EEPROM setting for Z-probe height represent?

What does the EEPROM setting for Max. z-probe - bed dist. represent? 

How are the two settings related?

Repetier

Z probe height is distance when probe trigger between bed and nozzle.

Max. z-probe - bed dist. is the distance between bed and probe while measuring. So if you have it 10 and start 100mm above bed it should only go 100 up after first probe. Something like that. Has changed a bit in implementation over time and depending on ig z home is at max (which it should be for autoleveling).

Use M119 to see if z probe is high or not before probing. If it high without being triggered you need to invert the signal to get it working or you never see a z move while probing.

briankb

Thanks for that!

So if the nozzle is still too high from the bed. What setting(s) do I need to adjust to move it down .01 or 1mm?

Repetier

If you did autoleveling, home and G1 Z0 and are too high lets say 1mm you decrease z probe height by 1 mm.

briankb

I tried and tried last night and couldn't get it to work on the Prusa i3 I built last week. I reverted to a mechanical switch end stop and will move the sensor to another machine or test it further.