[Delta] loading height map, got a warning



  • Hello,

    Just updated system files since a long time and realized that height map wasn't loaded, figure out that I'll need to call G29 S1 so I've added it to my bed.g. But I keep having the following warning when G32 is called.

    Warning: the height map was loaded when the current Z=0 datum was not determined probing. This may result in a height offset.
    

    here's my G28, homedelta.g

    ; homedelta.g
    ; called to home all towers on a delta printer via G28
    ;
    
    ; Use relative positioning
    G91 			
    
    ; Move all towers to the high end stopping at the endstops (first pass)
    G1 S1 X600 Y600 Z600 F2000  ; #COM F=speed
    
    ; Go down a few mm
    G1 S2 X-5 Y-5 Z-5 F1800 
    
    ; Move all towers up once more (second pass)
    G1 S1 X10 Y10 Z10 F200 
    
    ; Move down a few mm so that the nozzle can be centred
    G1 Z-5 F6000
    
    ; Switch back to absolute positioning and go to the centre
    G90
    G1 X0 Y0 F6000
    

    here's my G32, bed.g

    ; bed.g
    ; called to perform automatic delta calibration via G32
    
    M561 		; Clear any bed transform
    G28 		; Home
    G0 Z50 F4000	; Get ready for first probe.
    G31 P100 X0 Y0 Z-0.10 ; Set probe OFFSET
    
    ; bed.g file for RepRapFirmware, generated by Escher3D calculator
    ; 13 points, 6 factors, probing radius: 120, probe offset (0, 0)
    G30 P0 X0.00 Y120.00 Z-99999 H0
    G30 P1 X103.92 Y60.00 Z-99999 H0
    G30 P2 X103.92 Y-60.00 Z-99999 H0
    G30 P3 X0.00 Y-120.00 Z-99999 H0
    G30 P4 X-103.92 Y-60.00 Z-99999 H0
    G30 P5 X-103.92 Y60.00 Z-99999 H0
    G30 P6 X0.00 Y60.00 Z-99999 H0
    G30 P7 X51.96 Y30.00 Z-99999 H0
    G30 P8 X51.96 Y-30.00 Z-99999 H0
    G30 P9 X0.00 Y-60.00 Z-99999 H0
    G30 P10 X-51.96 Y-30.00 Z-99999 H0
    G30 P11 X-51.96 Y30.00 Z-99999 H0
    G30 P12 X0 Y0 Z-99999 S8
    
    ;CUSTOM
    M500 		; Save to config-override
    G28 		; Home
    G29 S1		; load last known bed compensation
    


  • Do you have a g30 in your home all file to establish z0 with the probe?



  • @Hergonoway Iā€™m having some problems with height maps today as well. Do you see the height map in the height map page?


  • administrators

    @Hergonoway, remove the G28 command near the end of bed.g. That will clear the warning and give you better results.



  • @Phaedrux said in [Delta] loading height map, got a warning:

    Do you have a g30 in your home all file to establish z0 with the probe?

    got a delta, homedelta.g is my homeall.g file, so no I don't have G30 in this file (see in my first post), but G30 is to probe the bed right ? my homing is at the opposite of the bed

    @jrsphoto said in [Delta] loading height map, got a warning:

    @Hergonoway Iā€™m having some problems with height maps today as well. Do you see the height map in the height map page?

    Yes I do, just had the warning šŸ˜®

    @dc42 said in [Delta] loading height map, got a warning:

    @Hergonoway, remove the G28 command near the end of bed.g. That will clear the warning and give you better results.

    Thanks, it cleared the warning message, but why will it give better results ?



  • @Hergonoway said in [Delta] loading height map, got a warning:

    Thanks, it cleared the warning message, but why will it give better results ?

    Because your bed.g is probing the actual bed surface, so it knows where Z0 actually is. When you home the printer again with G28 it's using the endstops at the high end of travel, so you're now resetting the location of true Z0 with the estimated position of the endstops.



  • @Phaedrux said in [Delta] loading height map, got a warning:

    @Hergonoway said in [Delta] loading height map, got a warning:

    Thanks, it cleared the warning message, but why will it give better results ?

    Because your bed.g is probing the actual bed surface, so it knows where Z0 actually is. When you home the printer again with G28 it's using the endstops at the high end of travel, so you're now resetting the location of true Z0 with the estimated position of the endstops.

    That's clear thanks. I start all my print with a G28 (legacy behavior from old times šŸ™‚ ), following your logic it may be even better (for me at least) to replace it for G32 (modified as above) at the begining of my prints ? (I'm not concerned with the little extra time)



  • Well G28 initially lets you get a good estimate on where the print surface is. Once it's been probed with G30 you've established the true location of the bed. As long as you haven't rehomed using the endstops or turned off the motors the location should be maintained even between prints. If you really wanted to stay consistent you could do a single G30 probe in the center of the bed before printing.



  • @Phaedrux good to know, thanks for the advice


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