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Need help setting up final calibration using config.g

Posted by shadowphile 
Need help setting up final calibration using config.g
September 18, 2021 09:03PM
I have a delta with a piezo z probe running RRF3.4b3. I have worked out the z-probe offset and confirmed it with both G30 S-1 and also G30 alone.
I have also probed out the mesh bed correction. It looks 'ok', not great (max height - min height is about .25mm)
Now I want to invoke mesh bed correction without having to run G29 and G32 but I can't enable the heightmap correction until I've established a zero datum.
I tried putting this at the end of my config file:
G28 ;home
G1 X0 Y0 Z5 ;go to Z=5
M201 Z100 ;set accel real slow (I found this keeps my piezo from triggering during the start of a probe and use it for my G29 and G32 runs)
M566 Z20 ;set jerk really low
G30 ;probe bed once to trim zero height.
M201 Z5000 ;return accel to high
M566 Z300 ;set jerk to high
G1 Z300
It all runs fine, except the web interface does not know I homed and zero'd already, still have to click 'Home' manually. Is this normal?

question: If I configure the Z=0 datum by a single probe to the bed, does a subsequent homing erase that offset?
question: I want to programmatically set the accel and jerk very very low for any z-probe moves. I have that control in bed.g but how do I ensure the same thing for heightmap creation? I am thinking that I might creat a mesh.g file and put M557 there along with adjustments to the accel and jerk so I can return them to high values afterword but I'm burnt trying things out and just need some deeper info than the docs provide.
I realize that by doing this, my bed and nozzle aren't at printing temps. My meshbed is too large to run before every print but I'm used to manually ensuring the physical Z=0 anyway so I'm assuming that G32 and G29 at room temp will still be mostly valid and only have to adjust for the thermal expansion before a print.

JFYI, here is my z-probe setup:

M558 P5 C"z_probe.in" H5 F1000 T4000 R.75 ; create z probe input and type. H is dive height, F is probe speed, T is travel speed, R is settling time
M557 R150 S30 ; define mesh grid, radius and step size mm
G31 X0 Y0 Z-0.17 P500 ; probe height from actual surface (Volcano)
Re: Need help setting up final calibration using config.g
September 19, 2021 04:00AM
How are you homing Z? If you are homing it using a Z probe and a G30 command, then you have already established the Z datum by probing, so all you need to do is to run G29 S1 after homing to load the height map. You can do this at the end of homeall.g if you want. If you are homing Z using an endstop switch then do a single G30 probe at bed centre before you load the height map.

We don't advise putting any movement commands in config.g. If you lose power during a print, when the power comes back on the print head may crash into the print.

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].
Re: Need help setting up final calibration using config.g
September 19, 2021 06:30PM
thanks for the reply. I have a delta and homing with the endstops.
I can understand not putting moves into the config.g file, although homing seems safe enough.
Which brings me back to one of my questions: Why is using homedelta.g within my config.g file not recognized by the web interface? It still says system not homed yet and won't allow any jogging.
Another question I had: If I adjust the zero level with a G30 and then re-run homedelta.g, will my G30 result be reset?

Based on your advice, here is my draft approach:
-Calibrate system manually with G32 then G29 and save with M500. I only want to do this when it seems necessary.
-After startup, run homedelta.g (this is the first thing I always do *manually* using the Home button, but see above question).
-Before a print, run a new macro that lowers the tip to Z5 and does a G30 to establish zero, then G29 S1 to enable the heightmap correction. (ideally it would go into the start of every print file from the slicer.)
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