Mesh grid don't work

matej1006

can i have i bed.g M561 disable any mah compesation or no?

jay_s_uk

@matej1006 disabling mesh levelling in bed.g in normal.
If you use the drop down compensation menu to define the mesh, it will tell you if you have too many points

DIY-O-Sphere

@matej1006 said in Mesh grid don't work:

yes i do G32 before i do G29

You only need a G28 before G29...
But you can use G32 to get measured values for the adjustment. The result is saved in the console. It makes it easy to adjust the bed with the leveling srews.

matej1006

@jay_s_uk where is that drop down compensation menu i can not find it?

jay_s_uk

@DIY-O-Sphere he does need to do it before as he has independent z levelling

jay_s_uk

@matej1006

DIY-O-Sphere

@jay_s_uk said in Mesh grid don't work:

levelling won't be applied unless G29 (or G29 S1) is sent.

You are right....
I would recomement to add "G29 S1" in homez.g.
That's the way I have set it up....

matej1006

ow this drop down menu ok sorry

my homez.g

if !move.axes[3].homed
  M291 R"Cannot Home Z" P"U axis must be homed before Z to prevent damage to tool. Press OK to home U or Cancel to abort" S3
  G28 U

; RRF3 does not permit Z homing without x&y being homed first. Popup window for convenience.
if !move.axes[0].homed || !move.axes[1].homed
  M291 R"Cannot Home Z" P"X&Y Axes must be homed before Z for probing. Press OK to home X&Y or Cancel to abort" S3
  G28 Y X

if state.currentTool != -1
  M84 U
  M291 R"Cannot Home Z" P"Tool must be deselected before homing. U has been unlocked, please manually dock tool and press OK to continue or Cancel to abort" S3
  G28 U

M561 ; Disable any Mesh Bed Compensation
G90 G1 X201 Y200 F10000 ; Move to the center of the bed
M558 F500 ; Set the probing speed
G30
M558 F50 ; Set a slower probing speed
G30
G32                         ; Run 3-point bed calibration defined in bed.g
G1 X0 Y0 F10000
G29 S1 P"heightmap.csv"			; Mesh bed

matej1006

@jay_s_uk new bed with 20 spacing

jay_s_uk

@matej1006 still looks like you have some hardware issues to correct.
you may be asking a bit too much of mesh levelling

fcwilt

Hi,

Late to the party - sorry about that.

There are number of incorrect statements that have been made here but let's leave those for now.

As mentioned you should work on getting the bed much more level before enabling mesh bed compensation.

You can create a 4 point mesh just to see the overall levelness of the bed.

I would suspect that your left and right rails are not in the same plane.

Frederick

Phaedrux

@jay_s_uk said in Mesh grid don't work:

=== Move === DMs created 83, maxWait 0ms, bed compensation in use: none, comp offset 0.000

Its showing as being in use, which is a good start.

Actually it's saying bed compensation in use: none. meaning nothing was applied when that M122 was sent. If it said bed compensation in use: mesh, that would mean it's active.

jay_s_uk

@Phaedrux good point. don't know how I read that wrong

DIY-O-Sphere

@matej1006 said in Mesh grid don't work:

G29 S1 P"heightmap.csv" ; Mesh bed

This line should also be in homeall.g. Please check that....

fcwilt

@DIY-O-Sphere said in Mesh grid don't work:

@matej1006 said in Mesh grid don't work:

G29 S1 P"heightmap.csv" ; Mesh bed

This line should also be in homeall.g. Please check that....

That is one approach.

But since mesh bed compensation is mostly a benefit to printing it is also appropriate to only load the height map at the start of a print - either with start.g or whatever feature the slicer provides to execute user code.

matej1006

Hello with a little help from @jay_s_uk i manage to het next results it's better but i still have minor problems
this is with bed in room temperature:
unknown (1).png
and with heat bed to 60 degree:

i have 4mm aluminium X gantry with linear guide see photo:
is this just to thick or what you think?

Phaedrux

@matej1006 Too thick, or not thick enough? Since the curve seems to go along the x axis it could be droop on the rail.

Assuming the screen shot with the linear rail is the X axis?

jay_s_uk

@Phaedrux that was my assumption as well

engikeneer

@matej1006 I agree with the others that your x-gantry is probably sagging down a bit which is causing the raised area in the middle of the bed, could also be your build plate has a slight curve to it (less likely).

One school of thought would be to try and stiffen up your gantry so it deflects less, but if you're getting decent print quality with the mesh compensation on, then I'd be tempted just to leave it. I'll admit my printer has a much worse looking buge in the heightmap that yours and I still get good, consistent first layers all over.

Comparing the cold and hot heightmaps you have posted, this might be expected - as things heat up, they flex. However, it could also be that the bed wasn't fully levelled the same (either manually or with auto-tramming) before creating either heightmap. On my corexy I always run the auto-tramming (via G32/bed.g) a few times until the deviations have converged before creating or loading a heightmap to ensure it is always levelled the same.

matej1006

@Phaedrux i will draw new one more solud ans try again