Odd behavior after upgrade

CthulhuLabs

homeall.g :

; homeall.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool v2 on Tue Nov 20 2018 10:49:57 GMT-0500 (Eastern Standard Time)
G91                     ; relative positioning
G1 Z5 F6000 S2          ; lift Z relative to current position
G1 S1 X-305 Y-305 F1800 ; move quickly to X or Y endstop and stop there (first pass)
G1 S1 X-305             ; home X axis
G1 S1 Y-305             ; home Y axis
G1 X5 Y5 F6000          ; go back a few mm
G1 S1 X-305 F360        ; move slowly to X axis endstop once more (second pass)
G1 S1 Y-305             ; then move slowly to Y axis endstop
G90                     ; absolute positioning
G1 X100 Y150 F6000        ; go to first bed probe point and home Z
G30                     ; home Z by probing the bed
G29 S1


; Uncomment the following lines to lift Z after probing
;G91                    ; relative positioning
;G1 S2 Z5 F100          ; lift Z relative to current position
;G90                    ; absolute positioning

bed.g:

; bed.g
; called to perform automatic bed compensation via G32
;
; generated by RepRapFirmware Configuration Tool v2 on Tue Nov 20 2018 10:49:56 GMT-0500 (Eastern Standard Time)
M561 ; clear any bed transform
G29  ; probe the bed and enable compensation

CthulhuLabs

So I am still having problems with this. The 4 probe points are still floating above the Z=0 location, and when I print my first layers are not as squished down to the bed as they used to be.

Phaedrux

Have you redone your z probe trigger height calibration recently?

https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe

CthulhuLabs

Yes I did.

There seems to be error between the Z homing, and the bed probing. For instance I just configured the probing to do 9 points. The center point is the same spot that Z homes. I then homed Z and then immediately probed the bed. I then got the values from heightmap.csv. Without changing anything I homed Z again and probed the bed and got the heightmap.csv values again. Here are the results:

1st probe:
xmin,xmax,ymin,ymax,radius,xspacing,yspacing,xnum,ynum
65.00,235.00,65.00,235.00,-1.00,85.00,85.00,3,3
0.000, -0.026, 0.049
0.011, 0.017, 0.026
0.032, 0.012, 0.066

2nd Probe:
xmin,xmax,ymin,ymax,radius,xspacing,yspacing,xnum,ynum
65.00,235.00,65.00,235.00,-1.00,85.00,85.00,3,3
-0.036, -0.057, 0.016
-0.024, -0.010, -0.008
0.000, -0.018, 0.035

What is interesting is the height map seems to have the same contour, but different offsets. Like the second height map is fairly evenly -0.03 mm lower than the first on all probe points. I am not really sure what exactly this means though.

Phaedrux

Please can you test the repeatability of your z probe by running the macro outlined here: https://forum.duet3d.com/topic/6962/m48-measure-z-probe-repeatability-and-print-to-serial-output/5?_=1585676517737

CthulhuLabs

M292
G32 bed probe heights: 0.017 0.018 0.017 0.017 0.020 0.020 0.019 0.019 0.018 0.020, mean 0.018, deviation from mean 0.001

CthulhuLabs

So I altered the Macro to this:

M291 P"Probe will be tested 10 times and return mean and standard deviation. Ok or Cancel?" R"WARNING" S3 ; User must click OK or cancel.
G28
M401
G30 P0 X150 Y150 Z-9999
G1 X100 Y150 F6000
G30 P1 X150 Y150 Z-9999
G1 X200 Y150 F6000
G30 P2 X150 Y150 Z-9999
G1 X150 Y100 F6000
G30 P3 X150 Y150 Z-9999
G1 X150 Y200 F6000
G30 P4 X150 Y150 Z-9999
G1 X200 Y200 F6000
G30 P5 X150 Y150 Z-9999
G1 X100 Y100 F6000
G30 P6 X150 Y150 Z-9999
G30 P7 X150 Y150 Z-9999
G30 P8 X150 Y150 Z-9999
G30 P9 X150 Y150 Z-9999 S-1
M402

To see if adding in movement operations would have a major influence on the results while still probing the same point. Here are the results:

G32 bed probe heights: 0.028 0.029 0.039 0.034 0.032 0.037 0.036 0.036 0.037 0.038, mean 0.035, deviation from mean 0.004

Phaedrux

At least we know the probe itself is consistent, but there still appears to be some backlash in your mechanics.

CthulhuLabs

I am just confused where this is coming from. I have checked X, Y, and Z and I cannot feel any slop.

mladen001

hi @CthulhuLabs did you find resolution for this. I have exact same behavior when upgrading from 2.02 to 2.051
also no mechanical issue to be detected

thanks