Looking for M420 (load stored Mesh) workaround.
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Greetings!
I read the M420 S1 (get bed leveling state) used in Marlin after a G28 to load the eeprom stored mesh, is not supported in RRF.
So I'm looking for a work around after a G28 in the Start Gcode. Any thoughts?
The G28
M420 S1allows you to "bed level" save to eeprom, and just reload the mesh during the start g-code from Cura.
Any thoughts?
Thanks!
Max
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I don't think that is the same workflow I mean.
"After a G29 bed leveling is automatically enabled, but in all other situations you must use M420 S1 to enable bed leveling. It is essential to include the command M420 S1 in the “Start G-code” in your slicer settings. If you have no bed leveling, or if there is no leveling data, then this command is simply ignored."
What I'm trying to duplicate in RRF. You execute a bed leveling once (not in the start g-code). You save that to eeprom.
In Cura - Start Gcode you have you G28 then a M420 S1 that uses the stored leveling "mesh". You don't run bed probing each time in your start G-code.
I see that M420 is not supported, that's why I asked.
This is specific to a dual color printing technique, that requires you to print the base layer, change the color and print the second color on top.
If you are familar at all with DCHEP on youtube, he did a video today on this process.
"Two Color PTFE Cutter Printed on an Auto Level Ender 3 V2 3D Printer"
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@westech from the part of the docs @fcwilt linked, you want G29 S1 to load the heightmap. You can also have multiple maps and specify the right file
S1 Load the height map from file and activate bed compensation. The default filename is as for S0 but a different filename can be specified using the P parameter.
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@westech probably also worth pointing out that in RRF there are two tools got helping with your bed. First is bed levelling (G32) which helps get the bed plane level (e.g. by helping you manually adjust the levelling screws or by autotramming if you have independent z drives). The second is G29 mesh compensation which is more meant for dealing with lumps, troughs and other unevenness in your bed surface.
There's a couple of good pages in the Duet documentation that explains the differences and how best to set them up, but ask away with anything that doesn't make sense
I use both on my machines, and I'm not sure of they're any different for dual colour setups (I just use them as normal with my chimera) -
@engikeneer Great info!
I have multiple printers and am trying to get Cura working well with marlin and RRF. Most things are the same, a couple like M420 are different, but I see you can get to the same en result.
Just my Start G-code has to be different for RRF.
I don't have any tramming issues so I'm pretty level. I'm printing on Mirror so that is particularly flat. But still with the BL Touch, I'd like to do a G29 and save it. Then not run that for each print since I doubt anything will change.
In the case of the Dual color printing. You can't run a G29 for the second color, because their is a part on the bed.
When you print the second color, the G28 will clear your bed leveling. That is my understanding of the M420 S1 next.
I think there is enough info here to figure this out.
Thanks!
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@westech said in Looking for M420 (load stored Mesh) workaround.:
When you print the second color, the G28 will clear your bed leveling. That is my understanding of the M420 S1 next.
Why do you think that would happen?
Once a mesh is loaded it stays that way until unloaded or another mesh is loaded.
Frederick
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@fcwilt said in Looking for M420 (load stored Mesh) workaround.:
@westech said in Looking for M420 (load stored Mesh) workaround.:
When you print the second color, the G28 will clear your bed leveling. That is my understanding of the M420 S1 next.
Why do you think that would happen?
Once a mesh is loaded it stays that way until unloaded or another mesh is loaded.
Frederick
Maybe G28 operates differently from Marlin:
"G28 disables bed leveling. Follow with M420 S to turn leveling on, or use RESTORE_LEVELING_AFTER_G28 to automatically keep leveling on after G28.
Usage"That was the reason for the initial question. In Marlin G28 then M420 reloads the mesh. But RRF does not use M420.
But it looks like G28 + G29 S1 gets you to the same place in RRF.
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@westech said in Looking for M420 (load stored Mesh) workaround.:
Maybe G28 operates differently from Marlin:
Well I don't know Marlin but in RRF G28 does not automatically disable mesh compensation.
You can disable mesh compensation with G29 S2.
So you could put a G29 S2 into your homing files if you want Marlin-like behavior.
Frederick
