First Layer and Extrusion Problems

Veti

G29 S1 ; Load previously set bed map

this should not be in the config.g

the mesh should be loaded after you have established z=0

so a good place is the start of your slicer g code

for the offset see
https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe#Section_Calibrate_the_Z_probe_trigger_height

Frederik

when i run first a true bed level and then a bed mesh compensation i get the following heightmap:

RepRapFirmware height map file v2 generated at 2020-11-20 14:53
xmin,xmax,ymin,ymax,radius,xspacing,yspacing,xnum,ynum
0.00,340.00,0.00,370.00,-1.00,20.00,20.00,18,19
2.000, 1.878, 1.875, 1.890, 1.685, 1.642, 1.517, 1.442, 1.358, 1.253, 1.180, 1.145, 1.135, 1.138, 1.160, 1.177, 1.250, 1.333
1.715, 1.562, 1.735, 1.757, 1.603, 1.550, 1.423, 1.320, 1.240, 1.132, 1.075, 1.030, 1.020, 1.020, 1.048, 1.062, 1.105, 1.183
1.683, 1.645, 1.835, 1.725, 1.558, 1.397, 1.267, 1.160, 1.070, 1.010, 0.943, 0.925, 0.910, 0.922, 0.975, 1.005, 1.022, 1.100
1.635, 1.677, 1.760, 1.573, 1.440, 1.302, 1.163, 1.052, 0.970, 0.905, 0.847, 0.815, 0.802, 0.815, 0.855, 0.892, 0.930, 1.010
1.603, 1.555, 1.608, 1.442, 1.285, 1.150, 1.060, 0.953, 0.833, 0.755, 0.712, 0.690, 0.685, 0.695, 0.730, 0.770, 0.818, 0.927
1.483, 1.513, 1.510, 1.255, 1.155, 1.025, 0.943, 0.828, 0.795, 0.685, 0.597, 0.578, 0.573, 0.578, 0.613, 0.653, 0.722, 0.812
1.440, 1.442, 1.358, 1.160, 0.998, 0.858, 0.715, 0.642, 0.648, 0.542, 0.507, 0.507, 0.510, 0.533, 0.557, 0.610, 0.675, 0.775
1.478, 1.415, 1.267, 1.017, 0.917, 0.797, 0.743, 0.680, 0.615, 0.605, 0.432, 0.413, 0.420, 0.440, 0.455, 0.505, 0.573, 0.677
1.355, 1.205, 1.100, 0.875, 0.770, 0.672, 0.648, 0.590, 0.523, 0.417, 0.307, 0.300, 0.312, 0.333, 0.352, 0.392, 0.455, 0.555
1.212, 1.145, 0.953, 0.783, 0.632, 0.550, 0.560, 0.490, 0.360, 0.280, 0.203, 0.208, 0.225, 0.233, 0.238, 0.292, 0.352, 0.453
1.112, 1.010, 0.820, 0.632, 0.493, 0.390, 0.395, 0.347, 0.243, 0.158, 0.092, 0.100, 0.127, 0.120, 0.127, 0.163, 0.215, 0.333
1.005, 0.875, 0.705, 0.480, 0.358, 0.243, 0.212, 0.165, 0.115, 0.045, -0.010, 0.005, 0.010, 0.007, 0.012, 0.047, 0.097, 0.212
0.913, 0.750, 0.557, 0.318, 0.233, 0.108, 0.057, -0.002, -0.062, -0.110, -0.153, -0.148, -0.132, -0.137, -0.108, -0.068, 0.005, 0.095
0.797, 0.625, 0.425, 0.248, 0.127, -0.012, -0.097, -0.160, -0.220, -0.270, -0.283, -0.288, -0.270, -0.265, -0.227, -0.158, -0.105, -0.023
0.698, 0.483, 0.167, 0.115, -0.005, -0.145, -0.248, -0.302, -0.368, -0.440, -0.453, -0.475, -0.470, -0.430, -0.387, -0.315, -0.265, -0.182
0.500, 0.312, 0.070, -0.078, -0.193, -0.310, -0.408, -0.467, -0.552, -0.592, -0.575, -0.573, -0.578, -0.547, -0.495, -0.427, -0.350, -0.267
0.358, 0.160, -0.092, -0.172, -0.295, -0.415, -0.500, -0.573, -0.642, -0.665, -0.627, -0.595, -0.637, -0.640, -0.583, -0.515, -0.438, -0.347
0.265, 0.068, -0.240, -0.307, -0.420, -0.557, -0.640, -0.690, -0.735, -0.715, -0.660, -0.653, -0.730, -0.743, -0.698, -0.627, -0.542, -0.432
0.105, -0.070, -0.250, -0.320, -0.557, -0.677, -0.762, -0.797, -0.802, -0.773, -0.743, -0.795, -0.852, -0.833, -0.752, -0.670, -0.625, -0.517

Frederik

That is the orresponding height map picture from my DWC

Veti

post the output of 3 consecutive G32.

most likely your motor order is wrong

Frederik

1.G32
Leadjustments made: -2.618 -0.246 -0.521, points used 3, (mean, deviation) before (-0.997, 0.862) after (0.000, 0.000)

2.G32
Leadscrew adjustments made: -0.054 1.112 0.200, points used 3, (mean, deviation) before (0.399, 0.459) after (-0.000, 0.000)

3.G32
Leadscrew adjustments made: 0.044 0.756 -0.011, points used 3, (mean, deviation) before (0.228, 0.321) after (0.000, 0.000)

Frederik

i´ve checked the cabling.

left front spindle is connected to driver 2
back center spindle to driver 3
right front spindle to driver 4

fcwilt

Hi,

Do you lead screws really have pitch of 1.25?

Regards bed.g:

I'm not sure what having two P parameters is going to do to your bed leveling.

Why did you add the second P1.25?

Frederick

Veti

@fcwilt said in First Layer and Extrusion Problems:

Do you lead screws really have pitch of 1.25?

he has z400. where did you see 1.25 leadscrew?
M92 X160.00 Y160.00 Z400.00 E830.00 ; set steps per mm

Veti

@Frederik said in First Layer and Extrusion Problems:

1.G32
Leadjustments made: -2.618 -0.246 -0.521, points used 3, (mean, deviation) before (-0.997, 0.862) after (0.000, 0.000)
2.G32
Leadscrew adjustments made: -0.054 1.112 0.200, points used 3, (mean, deviation) before (0.399, 0.459) after (-0.000, 0.000)
3.G32
Leadscrew adjustments made: 0.044 0.756 -0.011, points used 3, (mean, deviation) before (0.228, 0.321) after (0.000, 0.000)

that seems to be converging. can you run a g29 now and post the picture

fcwilt

@Veti said in First Layer and Extrusion Problems:

@fcwilt said in First Layer and Extrusion Problems:

Do you lead screws really have pitch of 1.25?

he has z400. where did you see 1.25 leadscrew?
M92 X160.00 Y160.00 Z400.00 E830.00 ; set steps per mm

See his bed.g file.

He has two P parameters for each G30. Not sure if that is messing things up or not.

Frederick

Veti

@fcwilt

good catch.
yes the second P1.25 parameter should be removed. this is not a valid parameter for G30
your pitch is 8mm btw.

fcwilt

@Veti said in First Layer and Extrusion Problems:

your pitch is 8mm btw.

How can we be sure the pitch is 8mm? The config values might be wrong. Maybe the comment in bed.g is correct?

Clarification is needed from the OP.

Frederick

Frederik

ok ,i have changed it.

is it possible to create a homez.g file where it automatically probes the bed on three points and enable compensation ?

perhaps like :

; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool v3.1.7 on Wed Nov 18 2020 18:04:17 GMT+0100 (Mitteleuropäische Normalzeit)

G91 ; relative positioning
G1 H2 Z5 F6000 ; lift Z relative to current position
G90 ; absolute positioning
G1 X240 Y220 F6000 ; go to first probe point
G32 ; home Z by True bed leveling 3 points in bed.g

or do i have to include the three positions like

G91 ; relative positioning
G1 H2 Z5 F6000 ; lift Z relative to current position
G90 ; absolute positioning
G1 X240 Y220 F6000 ; go to first probe point
G30 P0 X330 Y240 Z-9999 ; Front Left
G30 P1 X150 Y0 Z-9999 ; Middle Back
G30 P2 X0 Y248 Z-9999 S3 ; Front Right and compensate 3mm

Veti

@Frederik

create a macro that calls G28 and G32

Veti

@fcwilt said in First Layer and Extrusion Problems:

How can we be sure the pitch is 8mm?

i cant, but there is a very high chance that isnt a M8 metric lead screw.

fcwilt

@Frederik said in First Layer and Extrusion Problems:

is it possible to create a homez.g file where it automatically probes the bed on three points and enable compensation ?

Yes.

But let's get some terminology straight - bed leveling is not homing.

Bed leveling does what the term suggests - it tries to level the bed.

Homing is the process of determining that an axis has moved to some known position "telling" the firmware where the hardware actually is.

Generally you need to:

home Z using G28 Z
level the bed using G32 and a correctly created bed.g file
set the Z=0 datum using a single G30 and the correct position for the probe point
load the height map (if you have created one) using G29 S1

fcwilt

@Veti said in First Layer and Extrusion Problems:

@fcwilt said in First Layer and Extrusion Problems:

How can we be sure the pitch is 8mm?

i cant, but there is a very high chance that isnt a M8 metric lead screw.

Agreed given the 8mm is a common value.

Frederick

Veti

@fcwilt

but you are right.

@Frederik there are several things you have been asked that you have not given an answer to.

Frederik

@fcwilt you are right it was a wrong setting from yesterday. its a normal tr8 4 stop with 8 Lead Spindle

Frederik

i had to test your tips one after the other.... now my z offset is working as it should.