Help require and appreciated with printing with PETG
Hello prusa community.
I don't even know where to start. A bit of background. I bought my printer ~6 months ago. Had some problems with it printing PLA, was a first layer issue. Followed the first layer print guide from this forum and i printed an almost perfect benchy. So i used up 2 spools of PLA and the time came to switch to the 2 spools of PETG i bought with the printer. I have a pure black and pure white prusamet. This is where things just went to hell. I am frustrated to the point of trowing off the printer from the 6th floor and buying a low-grade printer.
So what is my issue ? I really don't know. I think i have several but can't say. So, I'll try to list the problems i see:
1. First layer randomly fails. One print is perfect and first layer looks ok. The next one fails dramatically with either stringing or the nozzle catching on the 0.2mm print and destroying it. Same settings! This is with the same settings !
2. Prints appear to be worse on the "left" side compared to the right side. This one is really weird. But happens consistently. You can see this on the pictures as i have provided. Can't say anything other tha this. I did bed leveling the nylock hack. octopi leveling etc. etc.
3. There are burns. Burns on random locations (both left and right side of the print). There is nothing consistent. Just happens from time to time. The nozzle touches the print ?!
4. Sticking to the nozzle. This one is insane. With PLA i never had to clean the nozzle. Now i have to clean it after every print. It just sticks to the nozzle. An not just the one that came with the printer too. I've used 2 other kinds as well - same result.
5. The nozzle tearing up already printed layers. Yes on the Z-leveling this happens without changing the settings. Let's say i am ad -1.217 at 240C. 1 print is OK the second one is tearing. And again - prints are "bad" on the "left" side.
6. There is warping on the sides. I have bought everything to make the LACK table enclosure but cannot print the parts to do it 🙁
I have not completed a single print so-far. Every print fails with burning or scratching plastic off of a previous layer etc.
I am mad and tiered and stress and really out of ideas. Can someone help me out or should i just now bother with this any more.
Things i have tried (in order). (Assume i was cleaning the bed and scraping off plastic after every print. I've been doing this for over a week now before posting here.)
* Did the nylock hack
* leveled the bed to 0.09 precision
* Moved the nozzle down a bit
* Tried printing at 230 - 260 intervals of 5 degrees.IE. 230,235,240,245,250,255,260 (heatbed is always on 80/85)
* Changed the nozzle with a Zodia CBR nozzle https://zodiac3d.com/collections/nozzles
* First layer calibration
* changed the nozzle with a Zodia PRO nozzle https://zodiac3d.com/collections/nozzles
* First layer calibration
* Puller my hair out
* Left the PETG in the oven for ~8 hours on 65 degrees.
* Leveled the bed to 0.1 precision
* Read all kind of posts and tried different things.
* Gave up on life* Did several cold pulls (some snapped, until i fugure out the best remperature to do it at)
* Came to the forum for help.
Can you please help ?
Best Regards,Webtemp
Z too low
Plenty of pics to prove this one. Your Z is too low. Wavy like water on that first layer is a dead give away. With PETG, this will then cause buildup on the nozzle, globbing, burns and dripping. And stringing. Second - your sheet is not clean enough. Get it to a hot water source and clean it with unscented dish soap (the blue stuff) to get all of the grease off - then only handle it by the edges.
Getting comfortable with live Z is what you still will need to do. It's not a setting. It's a per-print ritual until you get a sheet/spool/color dialed in. There no "set it and forget it" for live Z - though PLA is far more forgiving.
Finally, in the control panel settings, enable 7x7 bed mesh leveling. That will handle any minor leveling variations quite well.
And...
Couple more issues - made harder due to PETG
Moisture - you mentioned your PETG sat unused a few months. It could have absorbed moisture from the air ... read around here about how to dry filament.
Release agent - Once you think you got a wave-free first layer that is sticking - let's up the ante. PETG will tear up your smooth sheet if you don't weaken the first layer bond with a release agent. I use blue windex - just a spritz, then a quick wipe with a paper towel to spread it evenly (you want a very thin sheen of windex). This will be your first layer tuning exam - since too much windex will make the first layer not stick very well. Use your practiced first layer tuning skills to zero in a live-Z that works with PETG on a windex layer - and then you'll be ready to print PETG.
Thank you Dan Rogers !
First thank you very much for your response !
It's not a setting. It's a per-print ritual
Most epic words spoken in the 3d community.
Onwards to your advice.
Bed Cleaning
I follow instructions written here about the powder-coated bed. There it's said "When exposed to high humidity, it corrodes and loses its properties. Therefore, do not clean the sheet with water." so i do not clean it with water/soap. I only use IPA. I do clean it after every single print (the yellow sprayer from my pictures). However i see now i have made a mistake. I clean it while it is hot where it specifically says i should do it on room temperature. So tonight i'll clean it very good.
As for the Windex - there is no Windows in Bulgaria so i need to find a replacement for that.
Moisture in the filament
I have not attached a picture of that, but i mentioned it in the "things i tried" section. I heated the PETG for 8 hours. 8! 65 Degrees in an fan-oven. Will provide photos one i get back home.
Bed leveling
I already have the 7x7 bed leveling enabled.
Now for the big one.
Live Z
I have tried Z leveling in every possible variation. Specifically on this pic you can see many attempts on different temps.
Is any of these close to a good Z or are all of them bad and i need to make the Z higher ?
Temperature
I am seeing "better" results on 250C (and this is what's on the Prusament), however everywhere i read online and the default Prusa Slicer settings for PETG is 235C. However on that temp it does not even stick. Am i doing something wrong here as well ?
Again, thank you very much for taking the time to try to help me.
-1.485 looks the best.
Of those, which are all getting very close - your -1.485 looks the best to me
Agreed, -1.465 looks pretty good. And do yourself a favor — clean it with hot water and dish washing soap. Forget the Prusa warnings. In fact, I just noticed on one of their knowledgebase pages they did mention using water and soap, of course I can't recall where I saw it. Many of us are doing it routinely, and hell is likely to freeze over before your sheet rusts.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...