Been using prusaslicers default PLA profile with issues and this is my first roll of PETG, so I just selected the corresponding profile for that.
It seems so be super stringy whenever there’s movement and when printing the bunny (in vase mode) there’s lots of holes in the model.
I’m not sure if this is an issue with calibration (didn’t do anything when switching from PLA) or if the filament is wet.
Check for a partial clog. 80% of the time i get that consistency with petg, its because the nozzle is partially clogged. The other 20% is the ptfe tubing is shot. Usually it partially melts and causes underextrusion.
Wet filament could be an issue too, but this is pretty extreme for wet filament.
You were right! All clogged up.
Replaced the nozzle, heat block (heating element, sensor, PTFE) and fan duct. Wasn’t able to unscrew the nozzle (got stuck 80% out) so I replaced the whole thing.
Did two new temp towers:
Left tower is 235 (top) to 260 (layers labeled 280-260 are all 260). Right is 220-240.
https://i.imgur.com/1MQkStE.jpg
https://i.imgur.com/HDWq19A.jpg
I definitely feel like 220 is the right temp for this.
Make sure you calibrate your e-steps after swapping hotends. I did the same thing on my ender 3 putting on a volcano hotend, and started getting overextrusion. After adjusting the e-steps it was back to normal.
Do a temp tower. Find one hottest to coolest (260 to 220) and see where the sweet spot is. Going coolest to hottest could cause clogging.
And when in doubt make sure you PETG is dry. Likes to pull in the moisture. Tell-a-tale is popping and hissing.
Others: correct if I’m wrong but black PETG tends to be on the warmer side then other colours?
In my experience, moisture will cause excessive stringing in PETG long before it is saturated enough for popping/hissing.
I did two temp towers: 260-225
And
280-235
Although my printer didn’t want to go above 260, so the first layers are all 260.Yikes! Are you sure you sliced the temp tower for PETG profile? (as others have inquired)
I selected PETG filament profile in prusaslicer.
I wrote the custom layer change temp code to switch temps and checked in prusaslicer that temp changes occur the right places. (Using the color preview thing)
While printing I also saw that the temp did change where it should.
I think I’ll do a calibration of the feeding, or whatever you call it, where you measure how much filament is extruded. During some of the bridging, it looked like nothing got extruded.
It almost looks like 260 is the best temp. While extruding at this temp, I did heat lots of popping noise, which makes me believe the filament is wet. The noise did not occur at lower temps.
Kinda annoying when it’s a brand new roll.
What’s your print fan set to? I’ve had better results with fixed fan speed and much higher than default, but I use an enclosure. Is it popping or skipping? You’ll hear clicking if the filament skips, happens if you feed too fast, partial clogs etc. What brand petg? 260 seems high-ish, I tend to print hot in general but petg is usually 245-250 depending on the filament. What’s your speed like? If you’re enclosed definitely crank the print fan and maybe try slowing down.
Is your hotend clogged? Petg is the only filament I’ve had clogging issues with in the past. While printing, is it trying to cling to the nozzle? I’ve also found petg can try to climb up the nozzle, solved with a sock.
Update: replaced the nozzle, heat block (heating element, sensor, PTFE) and fan duct. Did two new temp towers:
Left tower is 235 (top) to 260 (layers labeled 280-260 are all 260). Right is 220-240.
https://i.imgur.com/1MQkStE.jpg
https://i.imgur.com/HDWq19A.jpg
I definitely feel like 220 is the right temp for this.
In regards to the fan, I actually read a post saying PETG wants almost no fan, so I just left it on default but maybe I should try a fixed fan speed.
I’m pretty sure the popping noise was clogged PLA burning like crazy at 260c…
I’ve always understood petg to really like cooling but I print in an enclosure so YMMV, it’s absolutely awful for bridges without cooling. Another thing to check would be extrusion multiplier and retraction. I get nozzle buildup if it’s overextruding which leads to blobs and stringing, worth tuning that anyhow
Been doing a couple of test prints with 30-80% variable fan speed and it’s actually pretty good looking with almost no stringing.
I unfortunately don’t have an enclosure, else I would for sure try and higher fan speed. Ad a slight draft this morning and my calibration cube print popped off half way through.
Update: replaced the nozzle, heat block (heating element, sensor, PTFE) and fan duct. Did two new temp towers:
Left tower is 235 (top) to 260 (layers labeled 280-260 are all 260). Right is 220-240.
https://i.imgur.com/1MQkStE.jpg
https://i.imgur.com/HDWq19A.jpg
I definitely feel like 220 is the right temp for this.
Huge difference!
Yeah I have Prusament Jet Black and 220/225 is the sweet spot for it on my setup.
That’s a shame you have to do all of the replacements but looks to solve all sorts of things for you.
BTW the keyboards in the background 😙👌
Thanks! Just two of my boards, SC Alice and Lily58.
You sure you are using the PETG preset? The only time my PETG prints have looked like that is if I accidentally use the PLA preset and it under-extrudes because the temperatures aren’t high enough.
That’s literally the first thing I thought of as well. A few times that I’ve mistakenly tried printing with a PLA profile while PETG was in the printer. Doesn’t get hot enough and really struggles to push the material through (for obvious reasons).
This could be it, OP should check what the actual temperature says on the screen during printing.
Yup, looks like way too low temps for me as well.
My vote is a combo but it includes being wet, is this a new roll or if not how did you have it stored? I have found PETG to be much more finicky with moisture than PLA overall so if you have a way to dry it definitely try that and see what happens before trying to calibrate it.
Brand new roll. I unfortunately don’t have any way to dry it :(
You can use your heated bed, just set a temp and cover the roll with a box.
https://3dprinterly.com/how-to-dry-filament-like-a-pro-pla-abs-petg-nylon-tpu/ Scroll down to the heated bed portion
I’ll have to try that!
I would try what that other person said, that’s a great idea!
Anecdotally, I actually just got through half of a brand new roll today that I opened two days ago and it has been printing from a dry box and it started spattering from trapped moisture (you will find little chunks of plastic on your bed in past experience) so it’s in the dryer now haha.
Hope it works out!
ETA: I live in CO, USA and the humidity in the room where the printer is currently reads 70.4F/50% and the dry box reads 12% for reference, not much for it to soak up from the air.
Aside from drying, here are some thoughts:
Double-check the print temperature, PETG should be about 240-ish. Also the spiral vase mode may be the issue if your model isn’t designed for it. Also check your z offset, the first layer should be almost a flawless sheet… if not, stop the print and try again while live adjusting the z until it’s correct. Typically PETG doesn’t like to be squished down as much as PLA.
Update: replaced the nozzle, heat block (heating element, sensor, PTFE) and fan duct. Did two new temp towers:
Left tower is 235 (top) to 260 (layers labeled 280-260 are all 260). Right is 220-240.
https://i.imgur.com/1MQkStE.jpg
https://i.imgur.com/HDWq19A.jpg
I definitely feel like 220 is the right temp for this.
I’ll try the bunny again, the model is designed for vase mode, so it should work!
I had one weird roll of PETG that could only be printed at lower temperatures, so it’s possible. Still looks like the filament is wet to me… I recommend picking up a Sunlu S1 Plus when it drops under $40, I like being able to both dry the spool and print straight from the dryer (only takes a couple hours to re-absorb moisture).
Dude! I just checked AliExpress for the Sunlu S1 Plus when I saw your message and was able to get one for $39 (shipped from Germany)! Thank you for that idea!
Make sure it’s from one of Sunlu’s official stores… aliexpressis pretty shady lol.
It is 😊 they had a coupon deal to make it that cheap
You could also mess with your retraction settings to try and reduce stringing.
