Setting live Z with PETG  

Re: Setting live Z with PETG

There may be different opinions out there.
I use the ame live Z for PLA , PETG, Stonefil and Flexible as well.
I couldn´t tell a difference.

Re: Setting live Z with PETG

Hi,

I had a very good experience with my i3 MK3 as I started printing initially with PLA; however suffered several setbacks when tried to print with PETG due to blobs, oozing and stringing. Fundamentally the problem I had was a combination of disproportionate amount of material coming out from the nozzle, no retraction as well as the nozzle rubbing against the freshly printed layers and as a result scratching the surface, accumulation of filament material on the nozzle which would eventually burn and fall on the printed model.

After reading several posts in Prusa i3 forum as well as discussion boards on other sites I was able to resolve the issue by adjusting the parameters such as printing speed, retraction speed, Z lift, retraction length, extruder temperature and extrusion multiplier. I posted my settings below for your information.

Printer Settings
Retraction Length: 1mm
Extra length on restart: -0.02

Filament Settings
Diameter: 1.72mm
Extrusion multiplier: 0.85
Extruder Temperature: 230/240
Bed Temperature: 85/90

Print Settings
Layers and perimeters
Layer Height: 0.2mm
First layer height: 0.35mm
Vertical shells / Perimeters: 2
All quality settings checked

Speed
Perimeters: 45mm/s
Small perimeters: 45 mm/s
External perimeters: 30 mm/s
Infill: 50 mm/s
Solid infill: 40 mm/s
Top solid infill: 30 mm/s
Support material 40 mm/s

Speed for non-print moves
Travel: 170 mm/s

Modifiers
First layer speed: 40%

The temperature, retraction speed and length solved the stringing and blobs while the extrusion multiplication factor also helped to improve the oozing problem.

However I think the most important change came after adjusting the Z level. I followed the first layer calibration and set up my optimal Z level using PLA material at -0.640mm. I then changed the material to PETG and observed the blob problem. Finally I started playing with the live Z level settings and found out that -0.720mm gave me the perfect result for PETG. With PLA the latter Z-level figure gives "OK" results however since I have both PETG and PLA Z-level settings recorded it's quite easy to quickly switch between two different settings if you're changing materials.

Good luck!

Best,

Ismayil

Re: Setting live Z with PETG

[...] Where can I obtain a file for PETG please?
The "life adjust" thread has links to files for PETG and other materials.

Re: Setting live Z with PETG

Thank you all for your setup recommendations and suggestions.

I'll have a try with the calibration surfaces and report back.

Regards,

Neale.

Re: Setting live Z with PETG

I have found that my live z is less negative for PETG.

Re: Setting live Z with PETG

This is a basic summary of what I do.

-Use Prusa Slicer. Use the default PETG settings.
-Print out a first layer square. Something like: https://www.thingiverse.com/thing:2797446 and adjust the live z while its printing the first layer to get the first layer height correct.
*You want the nozzle higher from the bed then you do with PLA. for example for PLA and PETG my z-offset is 0.2mm but my live z is .990 for PLA but .980 for PETG.
-Once first layer is looking ok I do extrusion calibration: https://help.prusa3d.com/l/en/article/d9j1xdg7vj-extrusion-multiplier-calibration
For example for me and the filaments I use PLA I at 1.05% and PETG i'm at 1.0% this gives me perfect first layer and perimeter wall dimensions
*Things to consider. To high or to Low temps/speeds will skew the results of the above.

Re: Setting live Z with PETG

Great stuff. Thanks.

Re: Setting live Z with PETG

hi
thanks ismayil.a ,for all research you did and test it's took long time i presume..

I set up my slic and test it on 2 small object , i do'nt have any problem with 1st layer really good and permiter wall as well ...

with your parameter i didn't get better result than with prusa PET parameter, so far ! the1st layer was excellent , the support was ok but same issue when take off support is not very nice and also the last layer finishing was external permiter not really good..

i printed with 0.10 detail ..and the Prusa orange filament one.

have to check again my Z layer may be!!! but with PLA i have so excellent result and sure so easy to take off the support and no finishing line too , but that PLA...

Re: Setting live Z with PETG

@Pat42 - I used 0.20mm resolution. Did you try the 0.20 resolution - if yes, did it work? The setting I posted won't work for 0.10mm resolution and you will need to tune/experiment with the following settings (recommended direction of change is shown in brackets):
Print Settings:
- [Layers and perimeters] Layer height (obvious one 😉 ) (reduce)
- [Layers and perimeters] First layer height, which you can set it as a percentage of layer height (reduce)
- [Support material] Options for support material and raft: Patter spacing (reduce)
- [Support material] Contact Z distance (reduce)
- [Support material] Interface layers (reduce)
- [Speed] Speed for print moves (slightly reduce small perimeters and external perimeters as a min.)
- [Advanced] Extrusion width - support material: use percentage or reduce value

What sort of problems are you running into? Do you have a picture you can share?

Re: Setting live Z with PETG

@Pat42 - I used 0.20mm resolution. Did you try the 0.20 resolution - if yes, did it work? The setting I posted won't work for 0.10mm resolution and you w
What sort of problems are you running into? Do you have a picture you can share?

thanks Isma , nope i didn't test w 0.2 , let me check and follow ur advice on print , at now honestly my print is really good on finishing 0 oozing or string , compare with the Recreus one i have quiet a lot of oozing , and my piece is nice at end , but my biggest problem is below support...yes i have some pics will share it ..
but like to test again ur set up ...too ..or may be improve too

Re: Setting live Z with PETG

What sort of problems are you running into? Do you have a picture you can share?
[/quote]
give you here pics , i am printing other piece now with the your all parameter, and on fast print so 20mm will check soon

thanks for share

Re: Setting live Z with PETG

What sort of problems are you running into? Do you have a picture you can share?
[/quote]

last print at 0.2mm et all your et up...happy but still fight with this crazy support on PET....at this time i adjust my Z from -840 to -900 ..