Trouble printing PETG  

RE: Trouble printing PETG

Sounds rather like you are not printing your first layer low enough. Can you post some pictures of a PETG first layer calibration for the Satin sheet using the default PETG settings?

Have you been using the Satin sheet for PLA as well? Normally PETG likes a little less 'squish' than PLA.

Cheers,

Tim

RE: Trouble printing PETG

I switched to the satin because that was what I thought was recommended.. See layer height below. Do you think I should drop it lower?

RE: Trouble printing PETG

Be sure that your build plate is truly clean and that your Z calibration (that's what Tim meant) is optimal.

I always use the 3x3 test print, several versions in the prints section.  This expands on the built-in Z calibration in that it checks the entire build plate and allows you to make adjustments to left/right and front/rear if needed.

Also, don't be afraid to use an adhesion booster, such as Layerneer or Magigoo (or hair spray or Windex).

PETg is a bit more tricky to print with than PLA but it produces excellent prints.  I've used it on both the smooth and textured build plates on the Prusa with very good luck.

RE: Trouble printing PETG

how do I optimize the Z calibration? I've just been using the auto calibrate..

RE: Trouble printing PETG

I have seen the exact same problem with PETG on a texttured sheet.  I use a smooth sheet for printing PETG because of this.  If someone else has a solution for satin or texttrured sheets with PETG please post.  I think some can depend on whose PETG you are using.  I have had some success with one PETG maker (no longer available) with a texttured sheet using a glue stick.

RE: Trouble printing PETG

I have seem a difference in the 'z' adjustment in the first layer calibration for the smooth (.658) versus textured sheets(.928) on my printer.  Current firmware allows you to save a first layer calibration for each sheet you use.  Remember to switch sheets in the menu so the correct first layer calibration is used.

RE: Trouble printing PETG

The satin and textured sheets are about 0.4 mm thinner than the smooth sheet so you'll have to adjust your live z accordingly (about 0.400 more negative). 

RE:

Posted by: @mgoleta-2

If someone else has a solution for satin or texttrured sheets with PETG please post.  I think some can depend on whose PETG you are using.

I've had good luck with PETg on the textured original Prusa build plate, but others have reported adhesion issues.

A couple of years ago there was some evidence of particular plates being 'good' or 'bad', and it appeared to correlate with the manufacturer build code on the plate.  I apparently have one of the 'good' ones and it has the WA15 code.

There's also anecdotal evidence that (at least some of) the textured plates require 'seasoning', as in they get better with use, like a grill performs better after it's been used a bit.

As for a 'solution', I would suggest first making sure the surface is clean, as in absolutely free of dirt and oils and such.  I think it's most important that you do clean it, as opposed to clean it my way.  😉

Next, Z calibration needs to be spot on.  The textured plate cannot take a joke on the first layer with bad Z calibration.  As noted, you will need to calibrate for the specific textured plate that you are using.  I would suggest starting out with the internal Z calibration to get within the ballpark and then use one of those 3x3 test prints (or if you are masochistic, one of those full-frame prints) and be sure that the Z calibration is consistent across the build surface.

Also be sure that your filament is dry.

I almost always use Layerneer for PETg on the textured plate.  This performs both as an adhesion booster and as a release agent.  It's particularly effective for things such as small prints and small support footings which may tend to curl up.

RE: Trouble printing PETG

for adjusting Live Z, I use  "Life Adjust 'Z' My Way" by jeff jordan

https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/

there is a zipfile at the bottom of the first post. contsining test files for PLA, PETG and I think ABS... 

I used to use the individual sheet descriptions, in the LCD Menu but I have multiple sheets in textured. smooth and Silk & I have 4 Prusa Printers, so I started getting confused, so now I just do a new live adjust Z ,  if I change the build sheet. 

On my mk3S printer I can print PLA, TPU and PETG without adjusting live Z
I normally print on a textured bed for all three filament types. 

If the sheet starts giving adhesion issues, I wash it with Hot Water and Dish soap, then rinse with hot water and dry with plain paper towels. 

regards Joan

RE: Trouble printing PETG

I'm pretty new at this too, and as the poster, had troubles initially when I went from PLA to PETG. But all my issues were configuration things. Mostly my Z axis was not optimum and I also had to switch to glueStick on the smooth sheet (because of over-adhesion).. And you need to use a really thin layer of glue stick. I didn't find windex worked for me much. Some videos actually use a glueStick wash to get a nice layer.. but I found just a good even layer of glue and then WAIT until it dries to a nice clear shine works well. Just go over an area once with the stick.

You also need to get used to really nailing what a good Z axis print looks like. It took me quite a while. 

But PETG is now my favourite and maybe my most consistent filament (of PLA vs PETG) to print with. And I've printed with Prusa, Polymaker and Eryone. (PolyLite PETG is surprisingly good!) The only issue I have is that when I need supports, I have not tuned my settings enough and often the support fuses into the print. PLA is easier with supports. 

I ordered the Textured/Rough sheet (TL-21) and absolutely love it. Printing PETG on the rough sheet is much easier than using PLA on the smooth sheet. (I don't have satin) I never have to clean with anything but IPA and have never had any issues with release or adhesion. I read a bunch of threads on it because I did have adhesion issues the first few days.. But my biggest problem was that it is about .03 thinner so you need to recalibrate your Z. My next problem was that there was a bit of film on it which I scrubbed very well with soap & the sponge side of a dish cleaning sponge (I did not use the 'green' or more coarse side although I have read others have.. but doing that on my smooth PEI scratched it). Sometimes I forget to change the setting to the Rough sheet.. but it has been an absolute delight to use.. I'd never go back to the smooth sheet for PETG. Once the rough sheet cools parts just glide off. Your satin should work similarly to my rough sheet but may not release quite as well.

RE: Trouble printing PETG

Posted by: @mtk

how do I optimize the Z calibration? I've just been using the auto calibrate..

By 'auto-calibrate' I'm assuming that you mean the Z calibration with the rectangular lines and the one square to the left front.  Is this correct?

I'm attaching the 3x3 level test print that I use.  IIRC it came from the prints section here.

Slice it using the parameters for the filament you will be using.

Print it and look carefully at the squares.  All should be smooth with no holidays and no bumps or ridges other than the 'brush strokes' of the print head.

If you need to, you can then adjust the Z calibration for the best looking squares across the build plate.  If there's a significant difference between the left/right and/or front/rear squares, use the front panel to enter corrections.  The procedure for this is outlined on line here: https://help.prusa3d.com/article/bed-level-correction_2267.

RE: Trouble printing PETG

While "Live adjust Z my way" is the way to go, I found the calibrations squares used in the original description a waste of time and material. So I designed this simpler calibration strip to speed things up. 

To properly adjust my first layer (Live Z calibration), I use the built-in first layer calibration wizard in steps of -0.100 until I get a good zig zag pattern with the corners sticking and a reasonably looking square. I then switch to the calibration strip for fine-tuning in steps of -0.020 or even -0.010. The larger format makes it easier to read the results, compared to the in-built wizard, plus you can try up to 8 different Live Z settings in one print. After the first time there's usually no need to go through the whole process again, and the 6 minutes or so needed to print a calibration strip is enough, unless you make major changes to the hotend. 

RE: Trouble printing PETG

ahhh, I had no idea that the Z adjustment was interactive. Got it figured. Adjusted the Live Z and all good now! THank you all! 

RE: Trouble printing PETG

As mentioned above, the printer firmware will allow you to create profiles for your sheets.

https://help.prusa3d.com/article/steel-sheet-profiles_1955

This is super useful if you are switching materials and sheets often. 

RE: Trouble printing PETG

Posted by: @ssill2

As mentioned above, the printer firmware will allow you to create profiles for your sheets.

https://help.prusa3d.com/article/steel-sheet-profiles_1955

This is super useful if you are switching materials and sheets often. 

Agreed.  I hope the new firmware will allow you to do it from the computer or Raspberry.  The interface is clunky on the MK3S.  

RE: Trouble printing PETG

be sure to remember to switch your selected sheet profile to match the sheet you actually use!  You'll only make this mistake once more than likely lol

RE: Trouble printing PETG

Posted by: @ssill2

be sure to remember to switch your selected sheet profile to match the sheet you actually use!  You'll only make this mistake once more than likely lol

Is that not the truth?