Checking the trigger height ; can't do step 8
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I am trying to follow https://duet3d.dozuki.com/Wiki/Using_mesh_bed_compensation instructions for finding the trigger height of my probe (BLTouch). On step 8 it says to
"Send G30 S-1 to probe the bed without resetting the Z=0 position" but when I do that, it fails with "insufficient axis homed". If I home the axis before I do it, I am no longer where I want to probe the bed AND it runs a G30 which resets my Z=0.
What do I need to do to find my trigger height? -
@EricE555 if you follow the steps, you shouldn't be unhoming the axis
i like using this macro to measure the trigger height
;Calibrate BL Touch trigger height ; When we get variables we can define one here ; Uncomment when ready to use ; var RunningTotal=0 ; var average=0 ; If the printer hasn't been homed, home it if !move.axes[0].homed || !move.axes[1].homed || !move.axes[2].homed G28 M564 S0 H0 ; Allow movement beyond limits if move.axes[2].machinePosition < 6 ; make sure we have probe clearance G1 Z6 M280 P0 S160 I1 ; reset BL Touch G4 S0.5 M98 P"0:/sys/retractprobe.g" ; Ensure probe is retracted & reset G4 S0.5 M290 R0 S0 ; clear any baby stepping M561 ; clear any bed transform ; Jog head to position M291 P"Jog nozzle to touch bed" R"Set nozzle to zero" S3 Z1 G92 Z0 M291 P"Press OK to begin" R"Ready?" S3; ; carry out 10 probes while iterations <= 9 G1 Z6 M400 if sensors.probes[0].value[0]=1000 ; if probe is in error state echo "Probe in error state- resetting" M280 P0 S160 I1 ; reset BL Touch G4 S0.5 M98 P"0:/sys/retractprobe.g" ; Ensure probe is retracted & reset G4 S0.5 G30 S-1 M400 ; Uncomment when variables allowed ; RunningTotal=RunningTotal + move.axes[2].machinePosition ;average=RunningTotal/(iterations+1) G4 S0.5 ; Until variables come use this M291 P"Check console for results and enter average value in G31 Z parameter of config.g" R"Finished" S3 ;When variables come uncomment this ;G31 Z{average} ;M291 P"Trigger height set to : " ^ sensors.probes[0].triggerHeight ^ " Press OK to save to config, cancel to use until restart" R"Finished" S2 ;M500 M564 S0 H1 ; Reset limits ; Home Z
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Thank you for your prompt reply. I tried your script.
When I run it I get 10 instances of "Insufficient Axes homed for bed probing" and then M292 -> Bad command: 0 -
After figuring out what I did wrong, I was able to run this script.
I had changed M84 (idle timeout) to 10 seconds because the motors make a little noise. Once I put that back to something reasonable, I had the necessary time to adjust nozzle to the bed height and then continue the script without the errors.
Now we'll see if I can make use of this to have a good offset for the nozzle when printing.