Induction Z Probe on Z Max, NOT Z Min

Hi,

I think I am reading too much into the keywords that contain "Z_MIN*" to mean the Z Minimum limit switch pins...

I am on Marlin RC6.
I am using proximity sensor (NPN) at 5V connected to Z Max
My printer uses Z min for homing.
I want to use Z Max for Z probe / Bed leveling.
I have "//#define Z_MIN_PROBE_ENDSTOP" disabled in configuration.h
I have "//#define Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN" disabled in configuration.h
-- but notes in confiuration.h say I must pick one. - I will pick Z_MIN_PROBE_USES_ENDSTOP
-- notes in configuration.h says "Z_MIN_PROBE_PIN" sets pin to use - oh maybe this is it; I will change this to pin 19, the ZMax pin.

I have "//#define DISABLE_Z_MIN_PROBE_ENDSTOP" disabled in configuration.h

How do I do this? Making changes in configuration.h results in error -
#error A probe needs a pin! [Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN || HAS_Z_PROBE]


How do I tell it to use Z Max? What am I missing here - Mendel / Prusa's use Z Min for homing, too..

Edited 1 time(s). Last edit at 12/28/2016 03:06AM by Eddiie.

Zmin probe should be set to zmax pin so 19 is correct

Also from memory, z min probe endstop should be enabled, but this is dependent on your setup ie uses min endstop AS WELL AS a probe for bed leveling

Edited 2 time(s). Last edit at 12/28/2016 08:43AM by gavatron3000.

connect the probe to zmin and remove the mechanical switch, you the use the probe for zmin homeing and bed levelling.
However, i have had more consistant results useing a z max mechanical switch and probe on z min for levelling (useing repetier firmware tho atm)

Quote
obewan
connect the probe to zmin and remove the mechanical switch, you the use the probe for zmin homeing and bed levelling.
However, i have had more consistant results useing a z max mechanical switch and probe on z min for levelling (useing repetier firmware tho atm)

OH I got it now. It is Z probe OR Zmin mechanical switch, not both.

Makes sense.

Thanks!

Eddie: You can configure your machine however you want. But really... If you have a Z-Probe, you probably don't need a Z-Min limit switch. It will just add complexity. And most likely, things will be simpler if you put the Z-Probe on the Z-Min connector of your electronics board.

Hi Roxy,
I am slightly confused, I firstly set my probe on the Z min pin which worked or appeared to but when I tried to home Z the machine went through the homing routine but when the home position was reached i.e. X0.00 Y0.00 Z0.00 the Z axis raised to approx 10mm above the bed. So I refitted the Z micro switch to Z min pin and connected the probe to Z max pin resulting in perfect homing though when bed levelling was run the probe never reached the trigger point before the zero micro switch activated so as I said I am confused so I again removed the micro switch and reverted to probe on Z min pin and sure the levelling routine works fine and so does the homing routine but I cannot get the nozel to stay at Z 0.00 as soon as Z 0.00 is reached Z raises to +6.8 mm from the bed. I have tried to find setting in configuration.h file to adjust it but what ever I have tried I don't seem to be able to find the answer, can you please help or is this normal. Having G28 set Z0.00 then raising to +6.8 mm, when printing starts does the printer drop to the first layer height 0.2 mm.
I might say this is my third and latest home built i3 printer, I am trying to go one step further with auto levelling and colour mixing which seems a large leap forward but it keeps me busy and learning in my retirement.