Z-lift config for G29
-
You say the probe is already triggered after finding Z
What exactly does that mean? What is the Z position at that point?
Thanks.
Frederick
-
What kind of a probe is it?
-
It's an inductive Prusa PINDA knock-off.
The Z position at that point is reportet as 1.000 and visually correct.
M114 X:150.000 Y:110.000 Z:1.000 E:0.000 E0:-0.0 Count 12000 8800 400 Machine 150.000 110.000 1.000 Bed comp 0.000I tried moving the printhead up with G1 H2 Z10 F6000 before running G29 and the printer moves towards XY(Z?) 0 which I guess would be the first probing point for the mesh before reporting ...
Error: Probe already triggered before probing move started
...and halting at:M114 X:42.000 Y:8.000 Z:1.000 E:0.000 E0:-0.0 Count 3360 640 400 Machine 42.000 8.000 1.000 Bed comp 0.000What I think I am missing is something like Marlin's Z_CLEARANCE_BETWEEN_PROBES offset by which the probe/printhead would raise itself between mesh points - I sadly can't see or remember how or why this worked with my old .g config files in the 2.x version before
-
When a probe completes the Z position is supposed to be high enough that the probe is ready to do another probe.
However if the Z position is too low for the "first" probe then you can get a "already triggered" error.
So what is the Z position at the start of the probe that is failing?
Frederick
-
That would be 10.000 as commanded via G1 H2 Z10 F6000.
Mesh grid is defined as M557 X00:200 Y10:200 S20 so I assume that the first probing point would be X:0, Y:10, Z:1 and its quite possible that my bed is angled/warped enough to trigger the probe before it reaches there.
This is why I am looking for a solution where the probe would stay at a safe distance to the bed while traveling between mesh points.
-
@duetwifiuser said in Z-lift config for G29:
That would be 10.000 as commanded via G1 H2 Z10 F6000.
Mesh grid is defined as M557 X00:200 Y10:200 S20 so I assume that the first probing point would be X:0, Y:10, Z:1 and its quite possible that my bed is angled/warped enough to trigger the probe before it reaches there.
This is why I am looking for a solution where the probe would stay at a safe distance to the bed while traveling between mesh points.
Your G31 command in your config.g file says the Z Trigger Height setting is 0. Is that correct?
Normally that setting is a positive number. For example mine is 2.5.
When a probe is complete the Z position is the Dive Height (the H parameter in the M558 command) plus the Z Trigger Height (the Z parameter in the G31 command).
With your current parameters the Z position would be 1 + 0 - which doesn't allow much room for the bed to be out of level or uneven.
My dive height setting is 2 so the Z position would be 2 + 2.5 - which is plenty of room in most cases.
Frederick
-
Thank you so much!
I feel really stupid now...
The Dive height was exactly what I was looking for - setting it to a generous 10 makes the printer behave exactly like it should/did before.
Somehow the zero got lost during copy'n pasting between old and new config.g - guess even BeyondCompare can't help with bad eyesight
Again, many thanks!
-
@duetwifiuser said in Z-lift config for G29:
Thank you so much!
I feel really stupid now...
The Dive height was exactly what I was looking for - setting it to a generous 10 makes the printer behave exactly like it should/did before.
Somehow the zero got lost during copy'n pasting between old and new config.g - guess even BeyondCompare can't help with bad eyesight
Again, many thanks!
Glad I could help.
But what about the G31 Z parameter being 0 - is that truly the case. It is possible.
Frederick
-
About the 0 trigger height:
That isn't really true, the correct value would be 0.84
I know its a bit weird, but since the bed isn't ideal, I actually prefer the Duet to think that the nozzle is basically on the bed when in reality it is floating ~1mm over it so I never run the risk of damaging the sheet should I command some move and forget to raise Z first.
The offset is then compensated for in the slicer...
-
@duetwifiuser said in Z-lift config for G29:
About the 0 trigger height:
That isn't really true, the correct value would be 0.84
I know its a bit weird, but since the bed isn't ideal, I actually prefer the Duet to think that the nozzle is basically on the bed when in reality it is floating ~1mm over it so I never run the risk of damaging the sheet should I command some move and forget to raise Z first.
The offset is then compensated for in the slicer...
Well that is the first time I have heard of that approach - but I understand your concern.
You could also so it with the correct value in G31 then use a M290 command to set a Z offset.
Frederick
-
You are of course right and I should really rather do it that way...
I'll keep it as is for the sake of consistency with my Marlin machines where I don't trust myself to always remember to apply M290 again after clearing the eeprom
Cheers!
-
@duetwifiuser said in Z-lift config for G29:
You are of course right and I should really rather do it that way...
I'll keep it as is for the sake of consistency with my Marlin machines where I don't trust myself to always remember to apply M290 again after clearing the eeprom
Cheers!
You don't have to remember - you can execute it as part of your Z homing code so it will always take effect.
Frederick
