[BUG] G29 with negative probe Zoffset

[hac441]

Did you test the latest bugfix-2.1.x code?

Yes, and the problem still exists.

Bug Description

I have a problem with G29. I have a probe attached in my hotend. The probe is removable. And it is below the nozzle. I do G28/G29, and then I remove it. I have set Z_MIN_POS -18 and MANUAL_Z_HOME_POS -Z_MIN_POS. G28 works now great. But I have problem with G29. Proccess fails. Can anybody help me? Thank you in advance.

Bug Timeline

it started when I added the probe

Expected behavior

Do G28 and G29 properly.

Actual behavior

It does G28 correctly but in G29 it fails.

Steps to Reproduce

1. Set negative Z_MIN_POS
2. Do G28
3. Do G29
4. It probes the first point twice and then it returns a fial maessage.

Version of Marlin Firmware

v2.1.2.6 or higher

Printer model

Creality Ender 5 pro

Electronics

probe at Zmin

LCD/Controller

No response

Other add-ons

No response

Bed Leveling

ABL Bilinear mesh

Your Slicer

None

Host Software

Pronterface

Don't forget to include

• A ZIP file containing your Configuration.h and Configuration_adv.h.

Additional information & file uploads

I have a problem with G29. I have a probe attached in my hotend. The probe is removable. And it is below the nozzle. I do G28/G29, and then I remove it. I have set Z_MIN_POS -18 and MANUAL_Z_HOME_POS -Z_MIN_POS. G28 works now great. But I have problem with G29. Proccess fails. Can anybody help me? Thank you in advance.

[ellensp]

You don't set Z_MIN_POS -18 that says your hotend can go into the bed 18mm!

Set Z_MIN_POS 0
set #define NOZZLE_TO_PROBE_OFFSET { 10, 10, -18 } // change to correct values (X, Y ,Z) distance from hotend tip, sign indicates left/right, front/back and under/above
enable EEPROM_INIT_NOW to force eeprom to use default config values on a new firmware upload
re disable //#define MANUAL_Z_HOME_POS 0
disable //#define MIN_SOFTWARE_ENDSTOP_Z

[hac441]

OK, but I want Zmin soft endstop. I want it to prevent me from going under 0.

[ellensp]

If you probing a bed you need to go under Z0 if any part of you bed is lower than the point you homed Z

[hac441]

I found a temparary solution. I entered in motion.h, and added a line 167: min.z = (float) -17.85; Inthis way I have the z min endstop, and it can go to zero.(eg G1 Z0 F800)

[hac441]

The first line of get_manual_axis_limits() (I use Marlin v2.1.2.6)