Issues with mesh leveling.

Col_Clucks

@fcwilt Would it be better to do this in firmware by adding that in my bed.g or in my start gcode? or if I add it to g32 is it going to try and include it in my gantry leveling? This has the center probe added in.

; bed.g
; called to perform automatic bed compensation via G32
;
; generated by RepRapFirmware Configuration Tool v3.2.3 on Mon Mar 15 2021 19:09:36 GMT+0100 (Mitteleuropäische Normalzeit)
M561                                                       ; Clear any existing bed transform.
G28 ; home
G1 Z220 F10000
M558 F10000
G30

M558 F100 A5 S0.003
G30 P0 X33 Y106 Z-99999 ; probe near a leadscrew, half way along Y axis
G30 P1 X235 Y106 Z-99999 S2 ; probe near a leadscrew and calibrate 2 motors

;add here G30 X112 Y101

M558 F200 A1

G1 X10 Y210 Z10 F10000

fcwilt

@col_clucks said in Issues with mesh leveling.:

@fcwilt Would it be better to do this in firmware by adding that in my bed.g or in my start gcode? or if I add it to g32 is it going to try and include it in my gantry leveling? This has the center probe added in.

; bed.g
; called to perform automatic bed compensation via G32
;
; generated by RepRapFirmware Configuration Tool v3.2.3 on Mon Mar 15 2021 19:09:36 GMT+0100 (Mitteleuropäische Normalzeit)
M561                                                       ; Clear any existing bed transform.
G28 ; home
G1 Z220 F10000
M558 F10000
G30

M558 F100 A5 S0.003
G30 P0 X33 Y106 Z-99999 ; probe near a leadscrew, half way along Y axis
G30 P1 X235 Y106 Z-99999 S2 ; probe near a leadscrew and calibrate 2 motors

;add here G30 X112 Y101

M558 F200 A1

G1 X10 Y210 Z10 F10000

I put the commands to set the Z=0 Datum in my bed.g file.

But I don't understand your current bed.g file.

There is this section - the G28 is fine but what is the intent of the next 3 commands?

> G28 ; home
> G1Z220 F10000
> M558 F10000
> G30

There is this section - the G30s look fine but why the M558? Typically you set M558 once and use it for all probing procedures.

M558 F100 A5 S0.003
G30 P0 X33 Y106 Z-99999 ; probe near a leadscrew, half way along Y axis
G30 P1 X235 Y106 Z-99999 S2 ; probe near a leadscrew and calibrate 2 motors```

There is this section - you cannot probe a single point that way to set the Z=0 Datum. You have to use a G1 Xnnn Ynnn move to position the probe taking into account the probe X and Y offsets. Then you just do a plain G30.

;add here G30 X112 Y101

And at the end you once again use M558. Same observation as above applies.

Hopefully you can clarify things for me.

Thanks.

Frederick

Col_Clucks

I should probably add comments to my code when I'm asking for help haha.

@fcwilt said in Issues with mesh leveling.:

@col_clucks said in Issues with mesh leveling.:

@fcwilt
But I don't understand your current bed.g file.

There is this section - the G28 is fine but what is the intent of the next 3 commands?
> G28 ; home
> G1Z220 F10000
> M558 F10000
> G30

These commands run the gantry to the top and physically levels the gantry by hitting the top of my z axis. When the printer powers off the axis sags a bit and it want to get the gantry as close to level before I apply any correction. I changed the feed rate because the default rate was miserably slow to run all the way to the top and back down.

There is this section - the G30s look fine but why the M558? Typically you set M558 once and use it for all probing procedures.
M558 F100 A5 S0.003
G30 P0 X33 Y106 Z-99999 ; probe near a leadscrew, half way along Y axis
G30 P1 X235 Y106 Z-99999 S2 ; probe near a leadscrew and calibrate 2 motors```

Here I am setting the feed rate to a lower speed for accuracy before I probe for gantry leveling.

There is this section - you cannot probe a single point that way to set the Z=0 Datum. You have to use a G1 Xnnn Ynnn move to position the probe taking into account the probe X and Y offsets. Then you just do a plain G30.
;add here G30 X112 Y101

So this is how you would do it?

G1 X112 Y101;
G30;

And at the end you once again use M558. Same observation as above applies.

The last step is to move my print head to the park position. i am just changing the feed rate to make the move faster as I am impatient.

fcwilt

@col_clucks

So after the G1 Z220 F1000 the G30 is going back toward Z0 to probe the bed?

Are you aware with firmware 3.3 and later in the M558 you can do F10000:100 and obtain two feed rates automatically?

From the docs:

From RRF 3.3 you can provide two F parameters instead of one, where the second is lower than the first, for example F1000:500. When doing a plain G30 command, an additional probe will be done using the first speed to establish the approximate bed position, before one or more additional probes are done using the second speed. The first speed will not be used when probing at a defined point or when mesh bed probing.

In theory that would do what you want without having to change it with separate M558 commands.

You may want to try it and see if it works to your satisfaction.

You have the correct idea for setting the Z=0 Datum with the G1 move and then the G30.

But I don't know what your probe X and Y offsets are so I cannot confirm the G1 X and Y values are going to move the probe to the center of you bed.

As to the last M558 changing the feed rate - since it is not followed by a probing command what is it going to affect?

Thanks for taking the time to help me understand what everything was doing.

Much appreciated.

Frederick

engikeneer

@col_clucks said in Issues with mesh leveling.:
 G28 ; home
 G1 Z220 F10000
 M558 F10000
 G30

Why not just do this?

 G28 ; home
 G1 Z220 F10000 ;go up to level against the frame
 G1 Z10 ; Note, the feedrate is stil F10000
 G30

Saves having to redefine your probe speeds etc

Col_Clucks

@fcwilt The point I put is correct for the G30 but even after doing that it still isn't using the mesh.

Col_Clucks

@engikeneer The bed.g works just fine as is. I still need help getting the printer to apply them mesh though.

fcwilt

@col_clucks said in Issues with mesh leveling.:

@fcwilt The point I put is correct for the G30 but even after doing that it still isn't using the mesh.

Well perhaps something that happens after you enable the mesh with the G29 S0 G29 S1 is disabling it again.

Something in the slicer start code maybe?

Frederick

Col_Clucks

@fcwilt so I took that out and it is changing the z height now so great success there. However it doesn’t seem like it is correcting enough. That may be an issue with the pinda 2 I’m using so I’ll start looking there

fcwilt

@col_clucks said in Issues with mesh leveling.:

@fcwilt so I took that out and it is changing the z height now so great success there. However it doesn’t seem like it is correcting enough. That may be an issue with the pinda 2 I’m using so I’ll start looking there

It sometimes seems to be that mesh bed compensation is changing Z enough - though I can see the Z steppers moving tiny amounts.

Perhaps it is a speed issue and that some setting is preventing the Z steppers from changing fast enough to be at the correct height where the actual filament is being laid down?

I have no idea.

Frederick