Quote Originally Posted by Roxy View Post
Those numbers do not look correct. What version of the code do you have? It might make sense to being up RCBugFix which is the most current and fixed version of Marlin. You can get it here if you decide to do that: https://github.com/MarlinFirmware/Marlin/tree/RCBugFix

It would also be good to see a M48 V4 on your current setup so we can see how the Z-Probe is behaving.
Hi,

I'm on Marlin version 1.0.2-2.

Code:
Front-left point
>>> m48 v4
SENDING:M48 V4
M48 Z-Probe Repeatability test.   Version 2.00
Full support at: http://3dprintboard.com/forum.php
Positioning probe for the test.
1 of 10   z: 0.906500 mean: 0.906500   sigma: 0.000000
2 of 10   z: 0.908125 mean: 0.907312   sigma: 0.000813
3 of 10   z: 0.909250 mean: 0.907958   sigma: 0.001129
4 of 10   z: 0.908875 mean: 0.908187   sigma: 0.001055
5 of 10   z: 0.909500 mean: 0.908450   sigma: 0.001080
6 of 10   z: 0.910125 mean: 0.908729   sigma: 0.001167
7 of 10   z: 0.911000 mean: 0.909054   sigma: 0.001341
8 of 10   z: 0.911875 mean: 0.909406   sigma: 0.001563
9 of 10   z: 0.912875 mean: 0.909792   sigma: 0.001833
10 of 10   z: 0.913250 mean: 0.910138   sigma: 0.002025
Mean: 0.910138
Standard Deviation: 0.002025
echo:endstops hit:  Z:0.91

Front-right point
>>> m48 v4
SENDING:M48 V4
M48 Z-Probe Repeatability test.   Version 2.00
Full support at: http://3dprintboard.com/forum.php
Positioning probe for the test.
1 of 10   z: 0.853875 mean: 0.853875   sigma: 0.000000
2 of 10   z: 0.857125 mean: 0.855500   sigma: 0.001625
3 of 10   z: 0.859375 mean: 0.856792   sigma: 0.002258
4 of 10   z: 0.860250 mean: 0.857656   sigma: 0.002463
5 of 10   z: 0.861750 mean: 0.858475   sigma: 0.002745
6 of 10   z: 0.862250 mean: 0.859104   sigma: 0.002874
7 of 10   z: 0.863500 mean: 0.859732   sigma: 0.003073
8 of 10   z: 0.864375 mean: 0.860313   sigma: 0.003259
9 of 10   z: 0.865500 mean: 0.860889   sigma: 0.003478
10 of 10   z: 0.866750 mean: 0.861475   sigma: 0.003739
Mean: 0.861475
Standard Deviation: 0.003739
echo:endstops hit:  Z:0.87

Back-right point
>>> m48 v4
SENDING:M48 V4
M48 Z-Probe Repeatability test.   Version 2.00
Full support at: http://3dprintboard.com/forum.php
Positioning probe for the test.
1 of 10   z: 0.156000 mean: 0.156000   sigma: 0.000000
2 of 10   z: 0.156875 mean: 0.156438   sigma: 0.000437
3 of 10   z: 0.158125 mean: 0.157000   sigma: 0.000872
4 of 10   z: 0.158500 mean: 0.157375   sigma: 0.000996
5 of 10   z: 0.159875 mean: 0.157875   sigma: 0.001339
6 of 10   z: 0.168000 mean: 0.159563   sigma: 0.003966
7 of 10   z: 0.160875 mean: 0.159750   sigma: 0.003701
8 of 10   z: 0.160750 mean: 0.159875   sigma: 0.003478
9 of 10   z: 0.160250 mean: 0.159917   sigma: 0.003281
10 of 10   z: 0.160625 mean: 0.159987   sigma: 0.003120
Mean: 0.159987
Standard Deviation: 0.003120
echo:endstops hit:  Z:0.16

Back-left point
>>> m48 v4
SENDING:M48 V4
M48 Z-Probe Repeatability test.   Version 2.00
Full support at: http://3dprintboard.com/forum.php
Positioning probe for the test.
1 of 10   z: -0.233375 mean: -0.233375   sigma: 0.000000
2 of 10   z: -0.232250 mean: -0.232813   sigma: 0.000562
3 of 10   z: -0.231875 mean: -0.232500   sigma: 0.000637
4 of 10   z: -0.232125 mean: -0.232406   sigma: 0.000575
5 of 10   z: -0.232125 mean: -0.232350   sigma: 0.000527
6 of 10   z: -0.232125 mean: -0.232313   sigma: 0.000488
7 of 10   z: -0.232250 mean: -0.232304   sigma: 0.000452
8 of 10   z: -0.232125 mean: -0.232281   sigma: 0.000427
9 of 10   z: -0.232125 mean: -0.232264   sigma: 0.000406
10 of 10   z: -0.232125 mean: -0.232250   sigma: 0.000387
Mean: -0.232250
Standard Deviation: 0.000387
echo:endstops hit:  Z:-0.23

And G29 results
SENDING:G29
Bed x: 1.00 y: 1.00 z: 0.94
Bed x: 155.00 y: 1.00 z: 0.87
Bed x: 155.00 y: 179.00 z: 1.11
Bed x: 1.00 y: 179.00 z: 0.75
Eqn coefficients: a: 0.00 b: 0.00 d: 0.83
planeNormal x: -0.00 y: -0.00 z: 1.00
echo:endstops hit:  Z:0.75
I could try the the RC version but I have had problem with that version since I couldn't obtain z-probe offset without disabling the min and max software endstops