ADDING SCRIPT TO HAVE Z-PROBE 'PROBE' BED TO 0 BEFORE PRINTS.

noblebran

Hello my fellow Duetians,

I have been trying and I could paste about 50 different bed.g codes but I have had the nozzle slam into the glass, go way out and steppers grind, etc.

I am trying to add to my bed.g for my delta for the probe to come down, know the offset from the config or maybe I have to add it to bed.g again, make sure its zeroed and then the mesh and the print is zeroed out accurately and should be as accurate as possible. I put "I ADDED" but have since taken out as it doesn't seem to work. Any help / advice is greatly appreciated. Thank you greatly

Please see the code below and I am using a BL-Touch, Duet 2 wifi and a PanelDue 7i. Thank you.

; bed.g
; called to perform automatic delta calibration via G32
;
; generated by RepRapFirmware Configuration Tool v3.2.3 on Mon Jul 05 2021 14:33:32 GMT-0400 (Eastern Daylight Time)
M561 ; clear any bed transform
G28  ; home all towers
M190 S65  ;PRE-HEAT BEFORE AUTOCALIBRATE
; Probe the bed at 6 peripheral and 6 halfway points, and perform 6-factor auto compensation
; Before running this, you should have set up your Z-probe trigger height to suit your build, in the G31 command in config.g.
;G1 Z5 F10000; lower nozzle I ADDED
;G30 Z3.89; Check I ADDED
;G90; Absolute positioning I ADDED
G30 P0 X0 Y132.28 H0 Z-99999
G30 P1 X121 Y69.86 H0 Z-99999
G30 P2 X129.9 Y-75 H0 Z-99999
G30 P3 X0 Y-150 H0 Z-99999
G30 P4 X-129.9 Y-75 H0 Z-99999
G30 P5 X-121 Y69.86 H0 Z-99999
G30 P6 X0 Y59.15 H0 Z-99999
G30 P7 X56.09 Y32.38 H0 Z-99999
G30 P8 X64.95 Y-37.5 H0 Z-99999
G30 P9 X0 Y-75 H0 Z-99999
G30 P10 X-64.95 Y-37.5 H0 Z-99999
G30 P11 X-56.09 Y32.38 H0 Z-99999
G30 P12 X0 Y0 H0 Z-99999 S6
; Use S-1 for measurements only, without calculations. Use S4 for endstop heights and Z-height only. Use S6 for full 6 factors
; If your Z probe has significantly different trigger heights depending on XY position, adjust the H parameters in the G30 commands accordingly. The value of each H parameter should be (trigger height at that XY position) - (trigger height at centre of bed)
G29 ;SAVES FIRST LAYER POINTS

jay_s_uk

@noblebran do a G30 first. Then run G32. Your printer height must be incorrect

noblebran

@jay_s_uk said in ADDING SCRIPT TO HAVE Z-PROBE 'PROBE' BED TO 0 BEFORE PRINTS.:

@noblebran do a G30 first. Then run G32. Your printer height must be incorrect

I checked and the offset from the probe is that 3.89 I have as Z. The height of the printer is correct, but I was curious as too how to probe and make sure / verify the 0 height before a mapping?

noblebran

@jay_s_uk Or do you mean run the G30 but remove the Z3.89 after it? Wouldn't I then need to then set absolute dimensions or does the G30 command by itself do that?

jay_s_uk

@noblebran no, I mean run G30. It is a single probe that will then establish the distance between the endstops at the top of the machine to the bed. Then G32 will work correctly

Phaedrux

G30 Z3.89; Check I ADDED

That doesn't do what you think it does.

https://duet3d.dozuki.com/Wiki/Gcode#Section_G30_Single_Z_Probe

G30 will use the probe to find the bed surface. When the probe triggers it will set the current position to whatever you have set in G31 Z as the probe offset.

G30 is the best way to determine where the bed surface actually is. When you home to Z max as you do in a delta, you can't be totally certain that the M208 maxima position is accurate to where Z0 actually is. Even if you measure the Z max position accurately, thermal expansion of nozzle and bed can make the actual nozzle to bed position change.

Calibrate your probe offsets and then use G30 to determine Z0 before doing G32 so that you have an accurate reference for the bed position.

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

Phaedrux

@jay_s_uk said in ADDING SCRIPT TO HAVE Z-PROBE 'PROBE' BED TO 0 BEFORE PRINTS.:

It is a single probe that will then establish the distance between the endstops at the top of the machine to the bed.

Not really, it will tell you where Z0 is. If you want to measure the distance between Z0 and the endstops after that you could use G1 H3 Z4000 to measure the actual endstop position relative to Z0 and set the M208 maxima.

https://duet3d.dozuki.com/Wiki/Gcode#Section_G0_G1_Move

noblebran

@jay_s_uk Thank you.

noblebran

@phaedrux said in ADDING SCRIPT TO HAVE Z-PROBE 'PROBE' BED TO 0 BEFORE PRINTS.:

G30 Z3.89; Check I ADDED

That doesn't do what you think it does.

https://duet3d.dozuki.com/Wiki/Gcode#Section_G30_Single_Z_Probe

G30 will use the probe to find the bed surface. When the probe triggers it will set the current position to whatever you have set in G31 Z as the probe offset.

G30 is the best way to determine where the bed surface actually is. When you home to Z max as you do in a delta, you can't be totally certain that the M208 maxima position is accurate to where Z0 actually is. Even if you measure the Z max position accurately, thermal expansion of nozzle and bed can make the actual nozzle to bed position change.

Calibrate your probe offsets and then use G30 to determine Z0 before doing G32 so that you have an accurate reference for the bed position.

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

Excellent, thank you.

noblebran

@phaedrux said in ADDING SCRIPT TO HAVE Z-PROBE 'PROBE' BED TO 0 BEFORE PRINTS.:

@jay_s_uk said in ADDING SCRIPT TO HAVE Z-PROBE 'PROBE' BED TO 0 BEFORE PRINTS.:

It is a single probe that will then establish the distance between the endstops at the top of the machine to the bed.

Not really, it will tell you where Z0 is. If you want to measure the distance between Z0 and the endstops after that you could use G1 H3 Z4000 to measure the actual endstop position relative to Z0 and set the M208 maxima.

https://duet3d.dozuki.com/Wiki/Gcode#Section_G0_G1_Move

I will go through the Wiki's... Thank you. I do have the z-probe offset in G31 in the main config. I will add G30 and then do a G32.

I will confirm I can get this to work and then I will do a more thorough calibration including the nozzle M208 Maxima command. Thank you sir.

jay_s_uk

@noblebran you really want the calibrate a delta page. But I use the G30 trick when I make major changes to mine

noblebran

@jay_s_uk said in ADDING SCRIPT TO HAVE Z-PROBE 'PROBE' BED TO 0 BEFORE PRINTS.:

@noblebran you really want the calibrate a delta page. But I use the G30 trick when I make major changes to mine

What do you mean a delta page?

I incorporated the G30 'trick' and I believe it has worked for me, I am lost on the delta page. Sorry if I seem ignorant. Just learning and don't want to break anything.

Phaedrux

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

jay_s_uk

@noblebran sorry, thought I pasted the link to the delta page

noblebran

@jay_s_uk said in ADDING SCRIPT TO HAVE Z-PROBE 'PROBE' BED TO 0 BEFORE PRINTS.:

@noblebran sorry, thought I pasted the link to the delta page

All good - thank you

noblebran

@phaedrux said in ADDING SCRIPT TO HAVE Z-PROBE 'PROBE' BED TO 0 BEFORE PRINTS.:

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

Thank you