Printing PETG is just sucking  

Re: Printing PETG is just sucking

First off what is the speed of your infill? I dont know why but one of the last updates bumped the infill speed to 200.... which is WAY over twice as fast as I like. I dont go past 70 personally using esun petg from amazon. I like a first layer of 20mm/s with my temps at 235/80. works perfectly for me. I light scrub my plate with IPA and a white scotchbrite pad and a super small amount of windex. I think I gave more details in: https://shop.prusa3d.com/forum/how-do-i-print-this-printing-help--f63/petg-printing-suggestions-t19353.html

That whole thread had a lot of good petg information in it from many good sources.

Just reread my post on page2. At this point I dont really bother with any material other than petg and I have run around 5 or 6 kilo's of the esun stuff though my mk3! My build plate still looks more or less unchanged from that post and that's after printing petg for somewhere around 40 or 50 days (huh, I better check my print time when I get home, now I'm curious). I still use that white pad and IPA method every single print. I have never even needed to use dish soap on my plate.

Hope that helps!

Seth

Finally saw pics, they weren't loading for me at first. lots of first layer blues, what it looks like to me... and maybe a clogged nozzle. Read that other thread, I posted. Think your live z needs to go lower, and plate needs better cleaning, looks splotchy, but that's probably the gluestick, I dont know for gluesticks and petg, never used it.

Re: Printing PETG is just sucking

The issue goes beyond first layer, here is a benchy currently printing using same settings (except infill is 5%).

Notice the patchy layer? This is pretty normal when attempting a real print with PETG. Forming blobs happen as well.

Infill speed is 200mm/s2. I will bump it down for next print later today.

The blotchy look of the plate is the glue for sure. It was spotless prior to glue.

If I go any lower on Z it gets worse, more blobing, more patchy look. If I go higher it just doesnt stick at all.

Nozzle, it prints PLA fine, could it still be a clog?

I'm going to slow down my infill speed, and lower the Z, and ill post another first layer test.

Re: Printing PETG is just sucking

First thing, you might want to head to the Life Adjust My Way thread.
Your first layer, skirt included, is not right. I know I have to go about 80 microns more negative than PLA.

You should go with nothing but Slicer defaults until you get things handled. Why would you want your extrusion width at 150%?

Get your first layer perfect.
Reset to defaults.
Print something easy.

Then start messing with all the parameters.

PETG is not that difficult. You'll get there.

Edit: Looking at your settings again, I see that your first layer is 150%, not the width. My mistake. But I stand by the rest of my advice.

Re: Printing PETG is just sucking

Hey,

The pics show the 1st layer looks really melted. I noticed your temps are 250 / 240 nozzle and 75/90 bed and you have the fan enabled the whole time in cooling.

Having printed the Amazon PETG with success using 230 nozzle and 82 bed (really between 85 and 80 is Ok) the whole time - e.g. no difference first layer. I just took the preset ColorFabb NGEN profile and only adjusted the temps to start and that has worked for me. I don't know if you tried that, but it could give it a shot.

Re: Printing PETG is just sucking

I didn't look at your settings, but I have printed a few rolls of PETG successfully, with an occasional challenge.

1. Prusa PETG settings work perfectly for me, no change except perimeter, infill, support
2. Dry filament is important, I have had a lot of oozing and stringing with wet filament
3. Your images (interrupted line) look like you have an extrusion issue: clean nozzle with cold pulls, make sure bondtech tension is "just" right. Too tight or too loose both cause troubles.
4. clean your nozzle with a brass wire brush to remove plastic residues - helps to prevent sticking of the filament to the Nozzle
5. first layer can be a challenge, really needs to be dialed in carefully. THIS IS ESSENTIAL
6. TIP: slow down to 70 or 80% in the "TUNE" settings, at least during the first layer. Stay and watch throughout the buildup of the first layer. Stop and repeat in case of issues.

I have printed several kg of different brands and it's a really nice material.
At one time I had issues with sticking, and had to do follow the procedure above (clean, adjust 1st layer, slow down)

Oh, almost forgot:
Bed preparation should not be an issue! I have literally just gently wiped the dust off with my bare hands to leave a minimal layer of body oils. Still sticking. Never needed gluestick. At one point when I had first layer issues I cleaned with alcohol but the real issue was extrusion, a clean nozzle and correct 1st layer height.

Good luck! It's great material once you got it dialed in!

Re: Printing PETG is just sucking

Only 0.5kg 😀 welcome to the 3D frustration society - get used to it ....

I print significantly in PETG and whilst I understand and value Prusa experience the defaults they have for PETG are so far off that they're unusable for all but Prusa's PETG. PETG is something of a challenge and it is hugely dependent on the vendor formulation - some are better than others, you need to ignore the Prusa settings and apply what the vendor tells you, if the vendor can't tell you the best settings don't buy from them, my advice is to stay away from bargain basement PETG at least until you understand the material.

When printing PETG you need patience, this obsession with speed that some seem to have will not produce consistent or particularly good prints. PETG does not like to be rushed, it doesn't like too much heat, and will ooze like crazy if too hot, so even getting retraction set correctly can be a nightmare.

You also need to lift your Z height a little or it builds up on the nozzle. PETG doesn't like cooling fans much either and will stick to the nozzle even worse when the fan runs so it is a balancing act when you're doing small parts / solid infill and bridging, the new Prusa fan arrangement makes this problem even worse - so much so that I've reverted to the original cooling fan arrangement (I do run the R3 extruder parts though).

At 0.5kg you're not doing bad - I went through 2kg getting to know PETG.

I wouldn't attempt any speed above 35mm/s for any part of the print, my max setting is currently 30mm/s across the board, bridges I have at 20mms and solid infill at 25mm/s. Your first layer needs to be slow, the infill speeds in Prusa defaults are totally inappropriate, whilst they may work for Prusa filaments don't plan on them working for others they will result in pillowing or even making a lunar landscape out of the top surfaces of the print.

It is for these reasons that I now print only with Rigid Ink PETG - I'm dialed in for it, it is consistent. Most of the issues that I face now are mechanical - PETG is very sensitive to layer height. I'm afraid you will need to do similar, get dialed in for a manufacturer and stick to them - just because it says PETG on the box means nothing - I have different settings for different colours even from the same vendor (the pigmentation also has an impact).

It's hard to print initially but once you get it dialled in you won't go back to PLA I don't think - unless you are speed obsessed and then PETG isn't for you I'm afraid.

Re: Printing PETG is just sucking

.... the defaults they have for PETG are so far off that they're unusable for all but Prusa's PETG. PETG is something of a challenge and it is hugely dependent on the vendor formulation....

I have been printing 4 different brands of PETG and the default settings with a little reduced speed (i.e. 80%) have been working very well for me.
The oozing in my case stopped after drying the filament and ever since keeping all my filament in dryboxes.
No issues here at all with Prusa defaults.

As always - different people, different expectations - different experiences
Maybe you know much more about 3D printing than I do and have higher expectations 🙂
I'm very happy with my results

Re: Printing PETG is just sucking

Good advice above on different things, especially the dryness of filament. troubleshooting problems over the internet is never easy...

I have to go back to temperature. Looking at the Amazon PETG roll I have it states temp 230 - 240 and bed 80. Having the fan always on seems counterproductive when reducing the temp can do the same thing.

I really think 250 is too high. I do not remember where I read it, but I did read it and the suggestion was start at lowest temp and work up as needed. the example pics look like melted cheese on a pizza. I have never had a PETG print like that (granted I am a new user but still). I would suggest starting at 230, doing some of the first layer test squares and working up in temp from there. Also, dry PETG is important. it is pretty hygroscopic and will suck moisture out of the air quicker than PLA.

Check out this link: https://www.simplify3d.com/support/print-quality-troubleshooting/#overheating

Re: Printing PETG is just sucking

Thank you everyone.

I adjusted my Z, and infill speed, I also switched to hatchbox PETG (it arrived and was the color I needed).

My prints are perfect now!

Re: Printing PETG is just sucking

Thank you everyone.

I adjusted my Z, and infill speed, I also switched to hatchbox PETG (it arrived and was the color I needed).

My prints are perfect now!

Reassuring to hear! Post up some prints when you get them done!

Re: Printing PETG is just sucking

Well I switched to a powder coated sheet and struggles are back, I will post pictures when I am able to work those out.