mesh bed compensation

tom33

Hi,
I have some problem with my bed compensation. It works not very fine you can see the picture. the compensation works fine in some area but not every were.
![alt text]( image url)
![alt text]( image url)

tom33

@tom33

; bed.g
; called to perform automatic bed compensation via G32
;
; generated by RepRapFirmware Configuration Tool v3.2.3 on Wed Mar 31 2021 11:16:46 GMT+0200 (heure d’été d’Europe centrale)
M561 ; clear any bed transform
M291 S3 R"Bed Levelling" P"Voulez vous réaliser un palpage plateau ?" 
M291 S2 R"Bed Levelling" P"Assurez-vous que le plateau d'impression est monté et l'espace de travail libéré"
M291 S2 R"Bed Levelling" P"Le palpage plateau va démarrer - Veuillez fermer les portes - Température buse max 80°C"
M400
;M291 S3 R"Bed Levelling" P"Voulez vous réaliser un palpage plateau ?" T1
;M42 P ;Fermeture des portes + Verif portes fermées.
if heat.heaters[1].current > 81
   M109 S80
   M291 S1 R"Bed Levelling" P"T --> 80°C"
   M116
else 
   ;continue

M400
;G28 C
T-1
M280 P4 S180
G90
G53 G0 X250 Y250 Z50 F2400
M561
G29 s2
M376
G30 
G29  ; probe the bed and enable compensation
M400
G28Z
G29 S2
G0 X250 Y250 Z50 F2400 
T0
G30 S-2
M500
G28
G29 S1
M291 S1 R"Bed Levelling" P"Calibration plateau terminée"

tom33

@tom33
When I send M122 the bed compensation is enable

tom33

@tom33
I probe directly with the head of the machine

extract of config g

; Tools
M563 P0 S"E0" D0 H1 F0					                ; Define Extruder 0 drive 0 Heater 1 Fan 0
G10 P0 X-30.4 Y0 Z-30.620 						                ; Set offset
G10 P0 R0 S0 							                ; Reset initial tool 0 active and standby temperatures to 0C

G10 L2 P1 X37.60 Y20.00 Z0
M500

M558 P5 C"io4.in" H7.5 F300 T6000  
G31 P500 X0 Y0 Z-2.35                                    ; set Z probe trigger value, offset and trigger height

tom33

@tom33
start.g

M42 P0 S0
M98 P/macros/Machine/Safety/03_Porte.g
M98 P/macros/myUpTimePrint.g
;G28
G29 S1

tom33

@tom33 I have also tried with

G31 P500 X-30.4 Y0 Z-2.35 ; ```

fcwilt

@tom33

I will be glad to help but I need to study your code.

One thing I will mention now before I get into studying your code:

The developers have this in mind for using G32 and G29:

G32 will run bed.g.

G29 will run mesh.g.

In bed.g there should be the code for leveling the bed.

In mesh.g there should be the code for creating the height map that is needed for mesh bed compensation.

Bed Leveling and Mesh Bed Compensation are two totally different things.

You have put the code for using mesh bed compensation in the file bed.g. While this will work it is not as intended. There are commands in the DWC that expect the conventional use of bed.g and mesh.g.

It's your printer and naturally you are free to do whatever you like.

Now I am off to study your code. In the meantime could you post the image of your height map?

Thanks.

Frederick

fcwilt

@tom33

Please post your entire config.g file.

A few things to consider:

once you have homed your printer it should stay homed unless something goes wrong.
before creating the height map with G29 you should set the Z=0 Datum with G30 at some fixed position - I use the center of the bed.
before loading the height map with G29 S1 you should again set the Z=0 Datum as before.
you should create the height map with the bed at the temperature you are going to print at. I let the bed heat for at least 30 minutes before creating the height map.
once you have created the height map you should not need to re-create it unless something goes wrong.

Question: You have a G30 S-2 command in your bed.g file. Why is that?

Frederick

tom33

@fcwilt I'm not runing a G30 before each print

The G30 S-2 is to save the tool Z offset in the config-override

And when I'm doing the height map, the bed is well heated

fcwilt

@tom33 said in mesh bed compensation:

@fcwilt I'm not runing a G30 before each print

It needs to be done at the times I posted.

The G30 S-2 is to save the tool Z offset in the config-override

Tool offsets only apply to multi-tool printers. Is that what you have?

And when I'm doing the height map, the bed is well heated

That is good.

tom33

@fcwilt Yes I have two tool heads in the machine

I don't understand where I have to move the G30 S-2 ?

fcwilt

@tom33 said in mesh bed compensation:

@fcwilt Yes I have two tool heads in the machine

I don't understand where I have to move the G30 S-2 ?

So it's not a tool changing printer but tools are always present?

Frederick

tom33

@fcwilt Yes, I have just a system to up and down the second tool head

fcwilt

@tom33 said in mesh bed compensation:

@fcwilt Yes, I have just a system to up and down the second tool head

As you understand the firmware needs to know the locations (X, Y, Z) of the Z probe and the tools, relative to one another.

With a single tool system the tool XYZ offsets are the reference (all zero) and the Z probe offsets/trigger height are set as appropriate.

Typically with a multi-tool system the Z probe is the reference (offsets/trigger height all zero) and the tool XYZ offsets are set as appropriate.

Your are combining both approaches - which will work - it is just unusual.

Where did you get the code in BED.G - there is much there that I don't understand.

When configuring your tools you have G10 L2 P1 X37.60 Y20.00 Z0. Why the L2?

Thanks.

But back to your original problem. Have you updated start.g to include a G30 before the G29 S1? Recall that the G30 used to set the Z=0 Datum should always be at the same XY machine position.

Frederick