Looking for a little guidance in mesh bed leveling since this is my first attempt at this. I'm using a Precision Piezo so I think I need a pause before each probing process but I'm uncertain..

Using some code I found I assume this should be ran each time before a print so this should go in my starting code, does this look correct?

M561                      ; Cancel any existing bed compensation
M557 X15:290 Y15:290 S40  ; Define the probing grid
G29                       ; Probe the bed and save height map to SD

Thanks.

ampapa,

Which firmware does your printer use?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

DuetWifi v1.19

I found the wiki but wasn't sure about M208 and G92 commands and was looking for some practical experience.

Running a G30 and the probe is working fine but I'm a little confused on how its updating its position to -.1... I was assuming it would be 0. Does it get that information from the config.g file?

My config.g has the following..

M558 (P1/P5) I1 R0.4 F300 X0 Y0 Z0
G31 X0 Y0 Z-0.1 P600

Thanks,

Yes, the Z parameter in the G30 command tells it what the Z height is when the probe triggers. It's slightly below zero because the printer isn't infinitely rigid, so the head has to be commanded slightly below Z=0 to create enough force for the piezo to detect.

The M557 command can also go in your config.g file, assuming that you always want to probe the whole bed.

G92 isn't relevant to bed probing, except during the procedure for measuring the actual trigger height described at [duet3d.com].

M208 defines the axis limits of your printer and the positions at which the homing switches trigger. Its relevance to G29 bed probing is that any points in the grid defined by M557 that are deemed to be unreachable because of the limits set by M208 will not be probed.

HTH David

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanks David, that clears up a few things.

After performing a Mesh Bed leveling, when powering off and then starting up again will the 3D printer automatically read the file that was saved?

Is there any needed process/procedure that needs to run the next time the machine is started or just home it and go?

ampapa,

Quote
ampapa
Thanks David, that clears up a few things.

After performing a Mesh Bed leveling, when powering off and then starting up again will the 3D printer automatically read the file that was saved?

Is there any needed process/procedure that needs to run the next time the machine is started or just home it and go?

ampapa,

You need to run G29 S1 to load the height map. You can load it in your slicer start GCode or at the end of homeall.g if you like.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

As for pause, if you are probing great without one, don't worry about it. If you get false triggers then add R0.4 to your M558 command. The system will pause for 0.4seconds before diving to probe. You can use more or less depending on how mechanically noisy your machine is.

Quote
ampapa
Looking for a little guidance in mesh bed leveling since this is my first attempt at this. I'm using a Precision Piezo so I think I need a pause before each probing process but I'm uncertain..

Using some code I found I assume this should be ran each time before a print so this should go in my starting code, does this look correct?

M561                      ; Cancel any existing bed compensation
M557 X15:290 Y15:290 S40  ; Define the probing grid
G29                       ; Probe the bed and save height map to SD

Thanks.

ampapa,

Edited 1 time(s). Last edit at 12/31/2017 06:23PM by DjDemonD.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions