When to use - or + with M666

Hi all,

To be sure, what are the M666 parameters when I measure X,Y and Z tower :

X -0.35 Y +1.10 Z -0.95

I am tempted to say M666 X0.35 Y-1.10 Z0.95 is it right ?

After reading many posts, it begin to be confused for me :-)

Quote
lolocaledo
Hi all,

To be sure, what are the M666 parameters when I measure X,Y and Z tower :

X -0.35 Y +1.10 Z -0.95

I am tempted to say M666 X0.35 Y-1.10 Z0.95 is it right ?

After reading many posts, it begin to be confused for me :-)

Depends on which firmware you are using......

In RepRapFirmware, a positive M666 parameter will increase the height of that carriage, and hence increase the nozzle height when the effector is near that tower. In Marlin it may be the other way round.

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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].

In my first patch adding M666 to Marlin, it is the same: negative value will move carriage down nearer to the bed. The positive value was changed to 0 (i.e. ignored) since it is not safe to move carriage nearer to the endstop after you have already hit it. Anyway later patches may have changed this ... and I do not know since I do not use Marlin any more.

Repetier uses positive values as an indication the carriage should be moved down (i.e. it has just the opposite sign compared to Marlin). I do not know what happens when you try to use negative value in Repetier.

Hi all,

Ok thank you.
so now, after doing all calibration procedure again from scratch, after G28 and G32, I've the following auto level result :
"21:53:40 UTC+11G32
Calibrated 7 factors using 13 points, deviation before 0.178 after 0.014"

Just only one thing to resolve : all probe points (7) in the center have 1.45 for Z probe threshold however all probe points (6) on the bed periphery (near the max of bed radius) have between 1.35 and 1.70 Z probe threshold.
Can I resolve this with H parameter on each G30 commande in the bed.g file ?

Have a good day

Laurent

Hi all,

One question about H parameter in G30 command : do I have to give the real Z probe threshold to H for each point or the delta Z probe with correct Z probe ?
For example : all center Z probe threshold are 1.45. For Z probe threshold at 1.75, H will be 1.75 or 0.30 ?

Thank you for your help
Laurent

Yes you can use the H parameter on the G30 commands to adjust the trigger height at individual probe points relative to the norm. The H value gets added to the G31 Z parameter. So in your example, H0.30 would be correct.

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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].

Hello,

The last thing I have to setup is the scale. What is the parameter to modify to have a correct scale ?

Quote
lolocaledo
Hello,

The last thing I have to setup is the scale. What is the parameter to modify to have a correct scale ?

If your size is wrong on all axis XYZ then you steps/mm are off, if your size is correct in the z-axis but wrong in the XY-plane then you need to adjust the "L" parameter of the M665 command.