G32 w BLTouch and Z-endstop

jontek2

Ok, here's an update:

I've got everything to work with the BLTouch and my config now is the following:

; Z-Probe
M558 P9 H5 F100 T2000			; Set Z probe type/mode 9. H=Dive Height. F=Speed the bed moves
G31 X30 Y15 Z1.688 P25			; Z probe trigger value, offset in relation to nozzle. And trigger height adjustment

However i'm getting the following message when i'm trying to do a G29

 Error: G29: No valid grid defined for bed probing

My "Define Area for Mesh Grid Compensation" is the following:

Start coordinate in X direction: 0
End coordinate in X direction: 210
Spacing in X direction: 20
Start coordinate in Y direction: 0
End coordinate in Y direction: 210
Spacing in Y direction: 20

However, if try to enter G29 two more tries - it works. Is this a known bug or am I doing something wrong?

fcwilt

Hi,

What happened to M557 X5:170 Y5:170 S20?

Frederick

jontek2

170x170 was something i had in size from Smoothie.

M557 X5:170 Y5:170 S20

seemed to be something from an earlier firmware version.

fcwilt

@jontek2 said in G32 w BLTouch and Z-endstop:

170x170 was something i had in size from Smoothie.

M557 X5:170 Y5:170 S20

seemed to be something from an earlier firmware version.

I would put it back. It is taking into account the z-probe offsets, as it should.

Though I would be inclined to use X5:165 and Y5:185 to keep the z-probe away just a bit from X and Y max.

Frederick

jontek2

According to the documentation (https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe) the M557 commands is used for the Touch-Mi.

fcwilt

@jontek2 said in G32 w BLTouch and Z-endstop:

According to the documentation (https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe) the M557 commands is used for the Touch-Mi.

That is simply mentioned there because of the characteristics of that type of probe.

M557 is used to specify the area to be probed for mesh compensation.

From the docs:

M557: Set Z probe point or define probing grid
Parameters to define G29 probe grid (all values in mm)

Xaaa:bbb Minimum and maximum X coordinates to probe
Yaaa:bbb Minimum and maximum Y coordinates to probe
Raaa Radius to probe
Saaa Probe point spacing (RepRapFirmware 1.19beta10 and later also support Saaa:bbb)
Pnn or Pxx:yy (RRF 2.02 and later) Number of points to probe in the X and Y axis directions (alternative to specifying the probe point spacing)

jontek2

Hmmm then why are there a function in the GUI for "Define Area for Mesh Grid Compensation"?

fcwilt

@jontek2 said in G32 w BLTouch and Z-endstop:

Hmmm then why are there a function in the GUI for "Define Area for Mesh Grid Compensation"?

Does the same thing.

Using the command is my approach.

I have two macros for running mesh compensation.

The first sets up a simple 4 point grid just to get a quick view of the overall levelness of the bed. I first did this when I was leveling the bed manually.

The other is for the full mesh compensation using points on a 20x20 grid.

Each macro uses the M557 command to specify the desired grid.

With the most recent DWC using the menu option to specify the grid mentions the M557 command.

Frederick

jontek2

Alright, i'll look in to that.

What's your start G-codes? Do you run the G29 in the start G-code?

I'm currently using:

;;; STARTING SCRIPT BEGIN ;;;
G28	 ; Home
G29 ; Bed leveling
G92 E0 	; Zero extruder
G1 X120 E20 F600 ; Draw prime line
;;; STARTING SCRIPT FINISH ;;;

fcwilt

@jontek2

Currently I only run bed leveling (G32) and mesh probing (G29) manually from macros for two reasons.

They take a while and the printer seems to be doing well with just doing those processes occasionally.

My Z homing procedure...

clears mesh compensation
cancels any "baby-stepping"
homes using a end stop switch
sets the Z=0 datum using a BLTouch Z-probe
loads the most recent full bed mesh compensation file

This happens whenever Z is homed so the normal "begin print" process doesn't need any special actions related to them, it just does the normal things related to set temps, selecting tools, priming and cleaning nozzle, etc.

Frederick