1 Topic by Torque

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Topic: Press issues Z-offset and glass

MY extruder head rubs against the glass during printing. From what I have read, there should be a ~.1mm gap between the glass and the nozzle, but there is no gap when I try to print anything. I have homed x, y, and z, and my z offset is currently 4.00. I suspect the z offset is the issue.

I have tried printing in repetier host 0.85, as well as soliprint, but get the same results. This occurs with several different models.

If I let it run, it prints the rest of the model alright, but the bottom is weird.

The glass also slides, but that's a separate issue.

2 Reply by cptskippy

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Re: Press issues Z-offset and glass

Have you tried running the Z-Offset Configuration Utility in SoliPrint?  It will run a print job that prints lines on your bed with numbers and they line up with the utility's UI.  You select the correct print line and it configures your Z-Offset to match.

3 Reply by Torque

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Re: Press issues Z-offset and glass

I have run that multiple times. Once it goes past the first few layers, everything is fine. I fixed the glass by loosening the 4 screws on the metal bed.

I can't print anything that has anything important at the base though.

4 Reply by thatdecade (edited by thatdecade 2015-01-23 14:57:04)

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Re: Press issues Z-offset and glass

I had the same trouble initially, extruder head was too close to the bed and I would get lots of smearing on the first layer and then my filament would jam because the extruder wheel was pressing so hard.

To fix:
Go back into the z offset window in soliprint, use the 'New Z-Offset Selection' checkboxes to increase the z offset.  Click the checkbox for the best printed line, then press the button to save your selection.  Some pictures here: http://www.soliforum.com/topic/9236/pre … tructions/

Alternatively, you can use the Fine Tuning to select a non-automatic offset.  If you make a mistake (and are stuck air printing for example) use gcodes g502 and g500 to reset to factory settings, then try again.

5 Reply by skyefire

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Re: Press issues Z-offset and glass

I have a similar problem, except that the extruder head rams into the glass bed and scrapes along it during the entire "print" portion of the Z-axis calibration program.  This despite the fact the the multi-point Z-axis probing works flawlessly.  Video here:  youtube.com/watch?v=m0rgiUxy50k

After stopping the Z-axis calibration print phase, and manually jogging the Z-axis down, I find that the extruder is going "through" the bed by ~1.9mm.  I tried making a large (5mm) change to the "Fine Tuning" box in the Z-axis calibration screen, but that didn't change anything -- running Z to 0 manually (G0 Z0) resulted in the same 1.9mm overshoot.

6 Reply by rrssll

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Re: Press issues Z-offset and glass

I'm having a similar problem. I used the SoliPrint calibration. After the calibration routine it sent the G-code:
M851 Z2.50

In my case 2.50mm was my Z offset from the calibration routine. SoliPrint prints at the correct Z offset after that. However, when I try to print with Octoprint I get the behaviour described here. The extruder pushes down flat against the glass for the first layer.

So what I've tried is adding the M851 Z2.50 to my startup G-code in Slic3r. It doesn't seem to fix the problem.

7 Reply by carl_m1968 (edited by carl_m1968 2015-09-05 02:50:17)

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Re: Press issues Z-offset and glass

If you are using g500 and g502 to reset to factory values then the Z offset is being stored in an EEPROM. No matter what you set your slicer or host for the EEPROM will always over ride those settings. You need to see if you can read the EEPROM data using RepHost and it's EEPROM utility. Other wise you need to find out the correct G command to write the z offset to the EEPROM through a terminal and then save it.

Printing since 2009 and still love it!
Anycubic 4MAX best $225 ever invested.
Voxelabs Proxima SLA. 6 inch 2k Mono LCD.
Anycubic Predator, massive Delta machine. 450 x 370 print envelope.

8 Reply by rrssll

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Re: Press issues Z-offset and glass

I used M500 to save it. I confirmed with M851 (with no value it reads back the current setting).

When I issue a G1 Z0 from Octoprint my extruder is still a couple millimeters off the bed. That doesn't seem right but it seems to be the opposite of the problem while printing.

9 Reply by carl_m1968

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Re: Press issues Z-offset and glass

Those commands read the current EEPROM values. There should be one reported for your Z. Just modify that one to account for the difference you are seeing and then save it. EEPROM settings get priority over all other settings.

Printing since 2009 and still love it!
Anycubic 4MAX best $225 ever invested.
Voxelabs Proxima SLA. 6 inch 2k Mono LCD.
Anycubic Predator, massive Delta machine. 450 x 370 print envelope.

10 Reply by paul99

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Re: Press issues Z-offset and glass

This is how I solved the head rubbing against the glass during the first layers that would often ruin the print.
I use Simplify3D but I suppose this will work with any software you use.

First I did a Z calibration in Soliprint. That gave me a Z offset of 3.9mm.

Print a first layer in Simplify3d. The dreaded clicking thumping noise from the extruder pressing to tightly against the glass.
Stop the print - and enter following in the G code (not sure whether m500 is needed or not but in any case below  saves the new Z value into eeprom.

M851 Z3.80
M500

Restart a print - still some clicking noises at some areas of the fist layer .

Stop printing and reenter Gcode with 1mm less
M851 Z3.70
M500

I went on until only a few clicks would sound during 1st layer.

My final setting came out at Z= 3.65

The bottom layers are now even and shiny (I use hair spray) unless its a really large area.

I also do an extrude of 10mm prior the print - this seems to "clear" up the extruder some for that 1st layer.
Code I use to extrude
G91
G1 E10 F120
G90

I've attached picture of bottom layer - kind of hard to show the actual appearance.

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11 Reply by durk

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Re: Press issues Z-offset and glass

paul99 wrote:

This is how I solved the head rubbing against the glass during the first layers that would often ruin the print.
I use Simplify3D but I suppose this will work with any software you use.

First I did a Z calibration in Soliprint. That gave me a Z offset of 3.9mm.

Print a first layer in Simplify3d. The dreaded clicking thumping noise from the extruder pressing to tightly against the glass.
Stop the print - and enter following in the G code (not sure whether m500 is needed or not but in any case below  saves the new Z value into eeprom.

M851 Z3.80
M500

Restart a print - still some clicking noises at some areas of the fist layer .

Stop printing and reenter Gcode with 1mm less
M851 Z3.70
M500

I went on until only a few clicks would sound during 1st layer.

My final setting came out at Z= 3.65

The bottom layers are now even and shiny (I use hair spray) unless its a really large area.

I also do an extrude of 10mm prior the print - this seems to "clear" up the extruder some for that 1st layer.
Code I use to extrude
G91
G1 E10 F120
G90

I've attached picture of bottom layer - kind of hard to show the actual appearance.


Or you could have just done it the easy way and used Soliprints calibration tool for Z.  That will save the setting and if its off its usually because soliprint overwrote the firmware. 

You can just run the Z calibration tool over and over until you dial it in on there. 

Mine was set to 0.30 MM  so my nozzle was off in repetier Host I re calibrated in soliprint and all was resolved.

12 Reply by madfalcon81 (edited by madfalcon81 2015-12-23 20:31:23)

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Re: Press issues Z-offset and glass

durk wrote:

Or you could have just done it the easy way and used Soliprints calibration tool for Z.  That will save the setting and if its off its usually because soliprint overwrote the firmware. 

You can just run the Z calibration tool over and over until you dial it in on there. 

... so my nozzle was off in repetier Host I re calibrated in soliprint and all was resolved.


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