[Closed] PETG Question and Problems on MK3  

Re: PETG Question and Problems on MK3

I've done some work to get PETG and S3D working with my Mk3. It has taken a good bit longer than I expected. I still have some stringing depending on the part but so far I am satisfied with the output. I've attached my .fff file for import into S3D. See if that helps.

Re: PETG Question and Problems on MK3

I have been printing a whole spool of Hobbyking PETG and some more with Prusa PETG.
Standard Slic3r settings for Prusa PETG, 0,2mm

The first layer needed some adjustment, but then it printed very well, with only slight stringing.

Rough surface of the first layer sounds like nozzle too close to the print bed.
I am not an expert, but that was an experience I had.

You could try printing a large square and play with the live Z, see if you can get a good first layer.
If not I'd try to get another PETG filament - for me it has been workind so well I expect to print more in PETG in the future.

Re: PETG Question and Problems on MK3

I am printing successfully with PETG. I have a bit of random very fine hairy stringing, but PETG often tends that way.

Things I've found

This is just my current mostly-successful settings. I have not tried slowly ratcheting up the speed or iterating in on the best extrusion factor.

Re: PETG Question and Problems on MK3

Can't this be set in the slicer instead of manually adjusting each time you swap filament types?

Re: PETG Question and Problems on MK3

Can't this be set in the slicer instead of manually adjusting each time you swap filament types?

Probably. I don't know how to do it in S3D. I can adjust layer1 thickness/width/speed, but they aren't the same thing as adjusting the 'zero' reference.

Re: PETG Question and Problems on MK3

I have been having great luck with PETG, using the stock settings in Prusa Control and Slic3r PE. I use Inland PETG, which supposedly is made by eSun. Haven't had to slow down any, print at the same speeds as PLA. Only thing I have found is I have to either set the first layer to .3mm for PETG, or .2mm for PLA in Slic3r, or manually raise the Z about .1mm if using Prusa Control. There is some slight whispy stringing on more detailed parts, but the blockier stuff just prints perfect. I am using the sticker PEI, not sure how many people have the powder coated sheets yet. I am on the list though!

Re: PETG Question and Problems on MK3

I've had some success with PETG, but it's time to revisit my settings. This thread has been useful, thanks folks!

I wonder: why is there no preset for PETG in Slic3r Prusa Edition? I mean, it's what Prusa Research is printing with, and it seems like the second most popular polymer after PLA. Or are folks just using the PET setting? Are they synonymous?

Also any clues on making adjustments in Z in the gcode would be appreciated! I'd rather not do a live adjust every time I switch between PLA and PETG 😛 (And why does live Z adjust only want to work with PLA?)

Re: PETG Question and Problems on MK3

regarding Slic3r profile - PETG is PET modified with Glycol for FDM printing, and the Slic3r profile for Prusa PET works (I didn't even realize that it said PET and not PETG...)

Live Z adjust works with any material while printing, only the built-in z-level calibration asks for PLA.

I watch the first level after a filament change and adjust as necessary with the live-z adjust function.
A better practice would maybe be to put a GCode with a first layer calibration design for every material on the SD card and use that after filament change... Hmmm, I might just do that 🙂

Re: PETG Question and Problems on MK3

regarding Slic3r profile - PETG is PET modified with Glycol for FDM printing, and the Slic3r profile for Prusa PET works (I didn't even realize that it said PET and not PETG...)

Live Z adjust works with any material while printing, only the built-in z-level calibration asks for PLA.

I watch the first level after a filament change and adjust as necessary with the live-z adjust function.
A better practice would maybe be to put a GCode with a first layer calibration design for every material on the SD card and use that after filament change... Hmmm, I might just do that 🙂

Can you expand a little on that last thought? It sounds interesting.

Re: PETG Question and Problems on MK3

Can't this be set in the slicer instead of manually adjusting each time you swap filament types?

It can in Silc3r. In printer settings/Size and coordinates there is an entry for Z offset. I have this at 0.2mm for PETG but leave it at 0 for PLA and HIPS/ABS.

Regards,
Martin

Re: PETG Question and Problems on MK3

Live Z adjust works with any material while printing, only the built-in z-level calibration asks for PLA.

I watch the first level after a filament change and adjust as necessary with the live-z adjust function.
A better practice would maybe be to put a GCode with a first layer calibration design for every material on the SD card and use that after filament change... Hmmm, I might just do that 🙂

Hi Georg,

There is no need to create the different first layer gcodes, you can just use the build-in one, if you override the temperature setting.
Here is how I do it:

Pre heat your nozzle and bed to the required temperatures.
When the temperatures are set, go into the menu and select the first layer calibration.
When it asks if PLA is loaded, answer yes.
Then it will set the nozzle temp back to 215 C -> then go into the menu and select tune -> nozzle and set the desired temperature.
Now the printer will wait for the nozzle to reach the new temperature, and first layer calibration is executed with the new temperature setting.

Best Regards,

Robin

Re: PETG Question and Problems on MK3

I am also experiencing a lot of bed adhesion problems with my smooth PEI steel sheet, and they are driving me crazy.
I have seen some small warping / bed adhesion with the Silver PRUSA PLA, but the bed adhesion is becoming a problem with PETG, as even small parts come loose.
According to the info on the website the PEI on the smooth PEI steel sheets would be the same as the ones on the MK2S beds, however I never experienced this kind of issues on my MK2S, even when I exchanged the heated bed. Actually I was able to print PETG on the MK2S, with very good quality and with very little failures.
On the MK2S I needed to print on glue stick and even then the adhesion was strong, but now I am printing directly on the PEI (with glass cleaner wipe) and still have issues.
Sofar I have raised my bed temperature by 10 to 15°C and adhesion seems to improve, as with the 10°C the prints did not come loose but still has some warping. (am now waiting for the results of the +15 °C test)
Is the PEI of the MK3 the issue ? Or is the temperature performance of the MK3 bed with steel sheet much worse that a higher bed temp is needed to compensate ?
Any ideas ?

Btw: I am printing with Colorfabb Ecomony PETG, Nozzle 235°C and Bed 60°C (now bumped up to 75°C)

Re: PETG Question and Problems on MK3

I clean the bed with Windex throughly and then use glue stick on the area to be printed. This works for me, but I have not done a lot of printing with PETG.

Re: PETG Question and Problems on MK3

I've done some work to get PETG and S3D working with my Mk3. It has taken a good bit longer than I expected. I still have some stringing depending on the part but so far I am satisfied with the output. I've attached my .fff file for import into S3D. See if that helps.

This worked perfectly with me. I still cannot get SLIC3R to work for me.

Re: PETG Question and Problems on MK3

Thanks for the tips. I was struggling with PETG, now I reduced the speed to 15 on first layer, increased z a little and decreased the flow. Now the first layer finally sticks. Still some imperfections on that first layer, but it will be covered by next layers.
Slic3r works well