Z homing Marlin no endstop

Mostly Printed CNC - MPCNC Troubleshooting
1

Hi all,
I have built a MPCNC and i love it!!!

My last concern is about Z homing.
I dont’ t have a endstop for Z nor probe.

I reverse it in Marlin so M119 show that Z endstop is triggered.
But When i ask a Z homing it move a bit about 5mm.

Where in marlin i can disable this movement? meanning when i ask a z homing it don’t move and set the Z value to 0

Thanks to all,
Benoit from France

2

Homing is the process of the machine moving until it feels the endstop being triggered.

If you want to tell the machine, “This is zero”. You use G92.

G92 Z0

Or all three:

G92 X0 Y0 Z0

In the LCD, there is a “reset all coordinates”.

More info at Coordinates - V1 Engineering Documentation

3

Thanks Jeffe,
I think in missed the “@isathome” info before.

One more question about G92
Why i get this :
15:14:49.464 : N539 G92 X0 Y0 Z0*86
15:14:49.465 : X:0.00 Y:0.00 Z:0.00 Count X:0 Y:0 Z:4000

After G92 and @isathome i can’t move to negative Z value, any idea why?

4

Ok for negative Z values, just need to set soft endstops to off

5

@isathome is used in Repetier Host to tell it that the machine has been homed. Repetier Host does not “hear” the G92 command so does not reset its display of the axes being at zero.

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