Failed First Print - Fix for PETG Benchy that shifted after a couple layers on textured sheet?  

RE: Failed First Print - Fix for PETG Benchy that shifted after a couple layers on textured sheet?

Yes, thank you. I have seen the M104,  G code to turn off heating. It just doens't fail, it also then crashes along the bed, I'm not sure if the C1 saw this too.  I'm not letting Prusa ignore the problem, so I have to go along with the process.

RE:

UPDATE: 
Got my micrometer, measured the precision method cube walls in the print i mentioned earlier:
Could not be much more accurate (6 measurements on each of the four walls: 0.451 average with 0.001 standard deviation)! 
So no adjustment needed for extrusion multiplier (it would be 0.9978, not sure what resolution is for that field, but that seems close enough to 1 for me!).

I did this time do a thorough water+dish-soap ONLY cleaning.

Next print was a single layer calibration layer:
Calibration Strip for simple Live Z/First Layer calibration
I printed the large one. Profile was using z=-0.04 still: I assume the live adjustments are on top of this???
Maybe I wasn't using big enough steps?
Anyways, results in photos below: not sure how to interpret, and in any event no obvious problem.
So NEXT I just tried again to print that benchy: same problem! (Although it seemed to print a couple more layers than the first three tries before adhesion failure, when the thing started to get moved around by continued printing).

So what next??? Ruebarb: I could try turning off fan, although seems very odd that would be required.
I do have the advanced filtration installed.
So HOW does one go about disabling the fan?
And preventing the printer from automatically opening the vent???

Live Z Test Results

RE: Failed First Print - Fix for PETG Benchy that shifted after a couple layers on textured sheet?

If this is your bottom layer then it is definitely too high, so maybe detection if the bed jas some problems due to the filament buildup on the nozzle? I know that since introduction of the load cell in MK4/CoreOne it is extremely important to have a clean nozzle during bed calibration - which is especially annoying with the PETG which tends to ooze out.

Some people updated their start gcode to preheat the nozzle to the lower temps so that PETG is not oozing out,  then do bed calibration and then bump the nozzle temp higher.

Another option is to adjust z offset so that the first layer it more squished.

RE:

Interesting that you closed the vents. I have experimented with bumping first layer bed temp to 90c and chamber temp to 40c with vents 2/3 closed when fighting a warping print on the textured sheet. I did not think you would need that for a benchy but maybe it is worth trying.

RE: Failed First Print - Fix for PETG Benchy that shifted after a couple layers on textured sheet?

This is a case where you can benefit from a nozzle wiper mod. I've seen in the past 1st layer issues caused by an uneven bed mesh probe, which in turn was caused by melted plastic accumulating on the nozzle.

RE:

I recommend using the Live Z file I posted, 5min file. There are many ways to make this adjustment, this is how I do it.

Do not proceed to next, unless yes, otherwise repeat with lower offset. Making adjsutments, don't bother with a 3rd digits, beyond .005, just start with 0.01, 0.02, 0.03...

• Print in one piece
• Remove in one piece
• Review the 5 squares,
  • Front, uniform appearance, all the layers attached
  • Backside, good appearance, layers hard to see, all blended
• Lastly hold the entire thing up to a light and look for any holes, even tiny ones,  you'll see the light come through. 

RE:

Since I've been chasing Nozzle cleaning issue, which at this point appears software releated and not hardware, in my instance.  I've done alot of testing with this filament on 3 nozzles.

Here is what I have if it is helpful to you. The file attached has all the filament settings and printer settings, turn off fan, g code....

Diamondback

• Galaxy PETG Filament
  • Ext Multi 0.98
  • Temp 240
• Printer Profile
  • Z Offset -0.02
  • Elephants Foot: 0.5

HF

• Galaxy PETG Filament
  • Ext Multi 1.0
  • Temp 250
• Printer Profile
  • Z Offset -0.02
  • Elephants Foot: 0.5

Hardened

• Galaxy PETG Filament
  • Ext Multi 1.0
  • Temp 250
• Printer Profile
  • Z Offset -0.01
  • Elephants Foot: 0.5