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.

  • SymbioteSynapse@lemmy.world
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    1 year ago

    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.

  • blakcod@lemmy.ca
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    1 year ago

    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?

    • dack@lemmy.world
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      1 year ago

      In my experience, moisture will cause excessive stringing in PETG long before it is saturated enough for popping/hissing.

    • drudoo@lemmy.worldOP
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      1 year ago

      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.

      • blakcod@lemmy.ca
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        1 year ago

        Yikes! Are you sure you sliced the temp tower for PETG profile? (as others have inquired)

        • drudoo@lemmy.worldOP
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          1 year ago

          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.

          • morbidcactus@lemmy.ca
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            1 year ago

            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.

            • drudoo@lemmy.worldOP
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              1 year ago

              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://lemmy.kya.moe/imgproxy?src=i.imgur.com%2f1MQkStE.jpg

              https://lemmy.kya.moe/imgproxy?src=i.imgur.com%2fHDWq19A.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…

              • morbidcactus@lemmy.ca
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                1 year ago

                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

                • drudoo@lemmy.worldOP
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                  1 year ago

                  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.

          • blakcod@lemmy.ca
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            1 year ago

            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.

  • sj_zero@lotide.fbxl.net
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    1 year ago

    I found petg to be a lot more challenging to print with than pla, but there’s a lot of really cool benefits to using petg like it’s more permanent and more flexible.

    I think the first thing to look at would be raising the temperature of your extruder. Seems like it isn’t really flowing a lot.

  • stealth_cookies@lemmy.ca
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    1 year ago

    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.

    • Hazdaz@lemmy.world
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      1 year ago

      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).

      • poofy_cat@lemm.ee
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        1 year ago

        This could be it, OP should check what the actual temperature says on the screen during printing.

  • bigredgiraffe@lemmy.world
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    1 year ago

    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.

      • bigredgiraffe@lemmy.world
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        1 year ago

        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.

  • poofy_cat@lemm.ee
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    1 year ago

    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.

    • drudoo@lemmy.worldOP
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      1 year ago

      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://lemmy.kya.moe/imgproxy?src=i.imgur.com%2f1MQkStE.jpg

      https://lemmy.kya.moe/imgproxy?src=i.imgur.com%2fHDWq19A.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!

      • poofy_cat@lemm.ee
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        1 year ago

        You could also mess with your retraction settings to try and reduce stringing.

      • poofy_cat@lemm.ee
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        1 year ago

        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).

        • drudoo@lemmy.worldOP
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          1 year ago

          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!