Printer smudging on x axis far side

Hi all,

As you can see in the photos I have a problem with smudging when printing.
Photo's here


I am using an Ormerod (RS branded) with a new (reprap sent me a new one) Duet board.
I did the bed plane compensation manually. I already knew the settings from the previous board.
I entered them in Pronterface manually, does anyone know if that is correct?
I manually typed in the below commands;
M561
M556 S100 X0 Y0 Z
G30 P0 X60 Y20 Z0.0
G30 P1 X60 Y180 Z-0.2
G30 P2 X180 Y180 Z2.6
G30 X180 Y20 Z2.8 S

On the far side of the X axis the print is smudges as if the nozzle were too close or something.
Can it be the bed plane comensation or is this sonething else?

When the print is complete, you can clearly see that on the far side of the X axis the printed part is thinner.

Davaka.

Hi Davaka, chances are your bed has moved a little since you last measured it - It's worth checking and re-entering the correct offsets at least each day (or each print for some!) until you know it's stable,

Cheers

Ray

1. The unmodulated IR sensor is sensitive to daylight and incandescent artificial light. This may affect your bed compensation procedure. It may also affect the x-axis homing position a little, but putting white tape over the homing tab (if you haven't already done so) may reduce this effect.

2. Always run the z-homing and bed plane compensation when the bed is up to printing temperature, especially if you haven't replaced or reinforced the mdf bed support. The mdf bed support tends to sag at the back corners (the amount will vary with temperature and humidity) and this affects the bed compensation.

3. I recommend adding the manual bed-levelling screws so that the automatic bed-levelling doesn't have much to do.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I see that your bed is over 3mm higher at the front than the back. In my opinion that is far too much - you should level your bed mechanically so that there is less than 1mm difference between any two points.

Dave
(#106)

Thank you all for your responses.

I have leveled the bed, replaced some of the nuts with washers and the maximum deviation now is at about 1 (0.90003).
When I start printing, On the far side it is going well. No more smudging and good solid lines and buildup.
On the close side (about X60) now it is too High. When I go to X60 manually and send G1 Z0, the nozzle goes up to the point where I set Z0.
When printing it is still too high on the close side.
Is there anthing else I may have missed?
Here is the Gcode I sent for the bed compensation;

M561
G28 Y0
G28 Z0
M556 S100 X0 Y0 Z0
G1 X60 Y30
(Down button - move Z down to almost onto the board)
G92 Z0
G30 P0
(Up button - Move Z up 3mm)
G1 X60 Y170
(Down button - move Z down to almost onto the board)
G30 P1
(Up button - Move Z up 3mm)
G1 X180 Y170
(Down button - move Z down to almost onto the board)
G30 P2
(Up button - move Z up 3mm)
G1 X180 Y30
(Down button - move Z down to almost onto the board)
G30 P3 S

Then I choose SD print and select circle.g and run that.

This should be correct right?

Why are you not using G32 to run the bed compensation? I'm not at all sure that your four G30 commands are equivalent.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I don't know,
Does G32 work better than G30?

Quote
Davaka

....Then I choose SD print and select circle.g and run that.

This should be correct right?

Yes that is correct and you should see the Z axis drive screw rotating if there is any difference in your four coordinate values

..and as the documentation say "You can put the Z readings you jotted down in a (setbed.g) file so you don’t have to do this every time the machine is run"

and..

"To set the bed compensation, just run setbed.g as if it were a file to print"

Erik

Quote
Davaka
I don't know,
Does G32 work better than G30?

Auto probing G32 would work just fine if the z probe would work but it don't, dc42 is working hard on that :-)

Erik

All,

U just ran G32. Went great.
I set the following probe coodinates;

M557 P0 X60 Y0
M557 P1 X60 Y170
M557 P2 X230 Y170
M557 P3 X230 Y0
G32

The callibration went fine. as far as I can tell. It moved to all four points and moved the Z down.
Now I thought it was time to start printing again.
On the far side it is too close to the heatbed and on the close side is is now about 1mm above the heatbed, not reaching the bed correctly.
What in the world am I missing or doing wrong?
Just now I even reflashed the firmware and started all over. Same result.

To make the IR bed calibration work reliably:

1. Ensure there is no direct sunlight or incandescent artificial light in the area of the Ormerod when calibrating the G31 value, doing Z homing, or running G32. LED and fluorescent lighting are OK. The G31 reading should be close to zero when the sensor is a long way above the bed. If you have a fine-tipped soldering iron, it is possible to change the values of the 2 resistors on the sensor board to lessen the sensitivity to ambient light. There is a modulated IR sensor in the works to resolve this issue.

2. If you followed the original instructions and used aluminium tape on the corners of the bed, remove it and use white PVC tape or white paper instead.

3. Check that your four M557 positions align the IR sensor head accurately over the white tapes, with a good margin around all 4 sides of the IR sensor head.

4. Preferably, don't put Kapton tape over the white tapes. If you do (because you need to print right up to the corners), make sure there are no joins, air bubbles etc. in the areas that the sensor is over.

5. When choosing the height at which to calibrate the G31 value, calibrating close to the bed is better, but the P value in the G31 command should not exceed 750.

6. Check that your X-axis is straight, so that the head is not sagging by a variable amount as it moves along the x-axis.

Edited 2 time(s). Last edit at 02/19/2014 09:12AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Save yourself the frustration and do the Z zeroing and take the bed compensation readings by hand until you have made one of the modifications to make the sensor more reliable. I do so before every print - once you are practised it takes just a couple of minutes.

Dave
(#106)

Thanks you for all your support
Rayhicks
dc42
and dmould

It proved very usefull. I am now happly printing and started working on my second Ormerod (the green one).

/Davaka