1 Topic by rcdailey2

  • rcdailey2
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Topic: Auto lvl Works, but inconsistent heights for print head

Hi All,

Solidoodle Workbench with Repetier-Host:


The real problem is the print head isn't putting the first layer down consistently.  Sometimes it drops the ABS from 2mm away and other times it places it so it squishes on the print bed.

Ok so it does the 16 point auto level, but it come up with different values back to back.  I'm not moving the sensor other than returning it to the 'down' position and I'm not moving the actual print bed.

I've tried fiddling with the 'first layer height', but it doesn't seem to do anything.  It's at .35mm or default.

I thought my failed prints were due to heat and not sticking to the print bed, not I've noticed all my successful prints 'squished' the 1st layer onto the bed when ALL the others dropped the ABS onto the bed.

Any help or fellow links would be helpful.

Thanks,
Doc

2 Reply by rcdailey2

  • rcdailey2
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Re: Auto lvl Works, but inconsistent heights for print head

Answer:

Manual Control tab

enter: M851 *send*

The value it spits out is where your probe head falls.  Increase the value to lower the head, increase the value to raise the head.

Figure out which way you want to move it and plug in a VERY small value.

enter: M851 Z###

This will now set the new print head distance.

To save if enter: M500

Now you can start to tinker with what feels right with how you want to print.

GOOD LUCK!!

-Doc

3 Reply by RaymondSheh

  • RaymondSheh
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Re: Auto lvl Works, but inconsistent heights for print head

How much free play do you have in the right hand Y carriage (the one without the motor in it)? I was finding that I had enough free play there to raise or lower the head by a couple of millimeters if the X carriage was all the way to the right. Of course if it doesn't shift between calibration and printing it doesn't matter - the printer compensates but I imagine if it calibrated in one position and then bumped itself to the other this could cause issues.

(I'm still trying to figure out how to tighten that but at this stage I've got bigger issues - like the extruders going crazy at random!)

4 Reply by soliryan

  • soliryan
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Re: Auto lvl Works, but inconsistent heights for print head

Looks like you've figured out how to change the Z offset, but also be sure there are no G28 commands after you run G29 as it will erase all the data measured by the probe.

Former Solidoodle employee

5 Reply by DarthGizmo (edited by DarthGizmo 2015-02-20 11:56:33)

  • DarthGizmo
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Re: Auto lvl Works, but inconsistent heights for print head

OOOOH wow Thank you sooo much for this thread I think this will solve one of my issues I was running a G28 after my G29 ran. only because I was just pasting a auto lvl into the gcode after slicing. Thank you SD employee.