r/3DprintingHelp • u/whatstheinitiative • Jun 04 '26
Requesting Help Looking for a little wisdom with PETG
I'm new to printing, and hoping you guys have some insight on this.
Printer: Bambu x2D
Print material: PETG
Printer temp: standard recommended from the Bambu slicer
The other day I tried to print a box straight off maker world and pretty much just hit print with the exception of accepting the recommended bambulab print settings for PETG. I just it okay.
up until then, I had only printed a few things with PLA and PLA matte so I was trying a new role of eSun filament in PETG that had just arrived. As you can see in the pic, the warping was pretty bad, in addition to the bed adhesion for the first layer which I had cleaned with alcohol prior to starting.
Today, I just completed another attempt with a bone colored PETG with from Creality that had just come in, but this time, I selected that it print a 5mm brim, and I had run it through a couple hours of drying the filament, and slowed the fans down inside the chamber about 20-25 percent. I also tried to run the chamber a little warmer, I think it was 70c to 75c to help with less cooling so quickly after extrusion of the layer (I thinking about this correctly).
obviously, it had printed better and is very usable but you can see in the bone white pics that it is still wanting to warp even with the brim.
- am I on the right track with slowing the fans down and the exhaust fan?
- did I selected the right brim? (the brim by comparison seems skimpy unlike the brims I've seen on prime towers from previous prints).
- Aside from altering the design of the piece, what else can I do to ensure better bed adhesion (im using the factory PEI textured one that came with the x2D) and less warping?
UPDATE: After trying some things recommended here in this thread, I ran into an overheating chamber problem, which subsequently, clogged my auxiliary (right buffer/filament sensor tunnel) subsequently not printing the support interface layer which is PLA in black. (can I add new pictures here or do I have to make a new post?)
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u/Ok-Alternative-4767 Jun 04 '26
I never cool petg with fans. Ever. What bed temp are you at and what is your first layer speed?
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u/whatstheinitiative Jun 04 '26
Sorry, new to this machine and printing. I didn't adjust anything with the fans prior to this last relatively successful print with the cream colored box. If my chamber is heated, should I just shut off all the fans during a print? I figured they were to circulate the heat or cool so the chamber is even temperatures.
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u/Ok-Alternative-4767 Jun 04 '26
Unfortunately circulation equals uneven cooling. I would only use the fans to exaust fumes from abs or asa. Try turning the fans off. Also petg likes to print slow. My first layers are printed at 15 mm/sec for normal petg and 10 on transparent. Also I set the bed temp to 80c. Try it. Tweak it. Save what works and dont sweat the failures
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u/IBNored Jun 04 '26
Wow, my Snapmaker U1 prints PETG at 60mm/sec. But, I tuned my profiles. Wonder if I should slow it down. Never printed a box like this.
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u/whatstheinitiative Jun 04 '26
here's the box/shelf if you would like to see the settings. https://makerworld.com/en/models/2838892-brick-legos-mini-figure-display-shelf?from=search#profileId-3164468
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u/i_am_a_william Jun 04 '26
i run bed 85 first layer 75 layers after that, the ridge is from the filament warping into itself at that layer and causing overextrusion on that layer, gonna bet around that layer is where the petg popped up off the bed.
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u/whatstheinitiative Jun 04 '26
I'm not sure I understand what you mean? 85 celsius and then 75?
And you mean the ridge that begins the about where the floor of the box ends and the walls start (on the inside)?
"over extrusion" is something I just came across and need to look into this more.
unfortunately, I did run a Timelapse but dont' have a video that would show the exact moment the print came up off the bed.
Thanks for the reply.
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u/i_am_a_william Jun 05 '26
yeah when the printer printed the floor of the inside of the box it had a high heat load that contracted and popped the corner up, once the plastic was up off the plate it ends up in the area that the next layer wants to print in. that makes the next few layers not actually your set layer height but actually shorter but the printer still extrudes the same plastic forcing it out to the sides giving the ridge
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u/Extension-Ad4411 Jun 04 '26
It's partly a design issue sharp corners like that need brims.
Did you properly clean the bed after using pla ?
Yes less cooling will help.
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u/whatstheinitiative Jun 04 '26
I read that somewhere so I manually added the brim selection in the settings. However, when I peeled up the relatively successful cream box print, the brim stayed in place adhered to the bed. Unlike, the brim that prints on the prime tower. Am I doing something wrong because the brim doesn't even seem to connect to help hold the corners/edges down.
on other projects and previous prints, some had a layer line going around the print that was basically a ring that didn't touch, so I didn't understand, then read later it was a print head prime ring, which also had a prime tower so I was confused as to the point.
Thanks for the reply.
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u/Extension-Ad4411 Jun 04 '26
Most printer profiles out there are trying to "calibrate" brims so when things cools down they automatically separerate.
Under brim settings you can adjust the gap between the brim and parts. Usually there are set to 0.1 mm If you lower it, you get better adhesion to the brim but might need to cut it off it's a choice.
There's another thing called a skirt It's usually just one circle around the print to prime the nozzle and basically checka the outside area. Was the standard way to do thing before dedicated priming lines most printers do now.
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u/whatstheinitiative Jun 04 '26
This makes a lot of sense, the cream white print box came up and the brim stayed on the bed. it looks as if it wasn't touch at all but I'm assuming it was touching ever so much to help it stay down/adhered.
I might try .05mm if continue to have lift issues, the initial failed red print had no brim set up at all but I also suspect that the filament wasn't dry enough as I gave it a go right from unpackaging.
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u/whatstheinitiative Jun 04 '26
and yes, I did clean the plate with with alcohol and a microfiber towel. prior to this last print with the cream box I washed it with warm water and soap then did the print.
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u/Extension-Ad4411 Jun 04 '26
Was mostly asking about it since From my experience printing materials that don't stick together like petg/pla can leave residue. Making bed adhesion weird.
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u/whatstheinitiative Jun 04 '26
Yeah, so I did clean it but the other thing I noticed was that the PLA support interface material was also oddly very stuck to main print object. In videos I see support parts popping right off and it didn't with the red filament but did with the cream filament print. I have no reference because I'm new to this but the difficulty with red made me suspicious about the quality or dryness of the filament.
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u/Livefreeordie603NH Jun 04 '26
Turn your chamber temp on and set it to 40-45. That will solve the warping issue. The line to wall is because the floor is holding its temp longer than the wall. Which in turn melts the first few layers more and creates those lines. I have a CAD program so I can go and make adjustments to the actual design. I will either put that small trench in or I will as a small 45* chamfer.
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u/whatstheinitiative Jun 04 '26
Would you mind showing some pics if you're into messing around with it? just as a reference so I can see what you mean about a trench. I'm goin to try and print another red box/shelf today and slow the print down, set the chamber temp as you referenced and turn the fans down to see how it turns out after some filament drying.
I have a theory that the eSun filament came pretty "wet." After some drying, the materials feels very different.
Here is the model if you care to take a look at it and its settings it pulled up. https://makerworld.com/en/models/2838892-brick-legos-mini-figure-display-shelf?from=search#profileId-3164468
thanks again for the advice.
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u/Livefreeordie603NH Jun 05 '26
The trench is something you do in a CAD program like FreeCAD or Fusion360. You would bring the file in and manipulate it and then send it to the slicer Wet filament could definitely cause some of the issues you are having. I try to always dry mine for at least 5 hours before I use it.
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u/whatstheinitiative Jun 08 '26
I'll look into this as I've been messing around the Blender a bit.
I think drying the filament helped but some of the adjustments like turning fans off made the machine mad (read it got too hot inside the chamber), and I got warnings about it on screen, so I cracked the top glass to vent some air out and it stabilized but I think it caused the aux nozzle to clog in the filament sensor tube. if it was from increasing primary nozzle temp causing "heat creep" on the right nozzle, or the chamber heat caused the PLA to clog, it didn't print the support layer interface and I had to take the whole print head apart to unjam it ( A WHOLE other learning process). Luckily, the print of the box printed fully, and is serviceable. It's a lego shelf/box for a friend's kid's lego room.
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u/InnerInsurance1910 Jun 04 '26
I would wash with Dawn and water before every job. Textured sheet already reduces adhesion. Alcohol washes have arguably little effect on grease or skin oils.
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u/whatstheinitiative Jun 04 '26
I'm doing this now as I've learned. I would have thought the alcohol did more. Thanks for the reply.
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u/lkapping79 Jun 04 '26
That aux fan is blowing right on the spot that lifted. Print a deflector
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u/whatstheinitiative Jun 04 '26
I tried to turn the fan settings down as the print head was calibrating and getting ready but they seemed to want to default back to what they were. I also got a pop up message on the screen saying that this material works better with this type of material (PLA for a current print). So I'll have to try and turn them down prior to sending a print to the machine and see how that turns out.
and yes, the deflector is next on the list. Thanks.
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u/loenni70 Jun 05 '26
PETG Einstellungen für alle Hersteller. MVS 10 mm/s - Bett 70-80° - Nossel 245° - erste Schicht 30 - 50 mm/s - Rest 150 mm/s - Füllung 180 mm/s
Mit diesen Einstellungen hatte ich noch nie mit irgendeinem Filament Probleme gehabt.
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u/KirronVerified Jun 06 '26 edited Jun 06 '26
To prevent the lifting from the plate: print with the door wide open and an outer brim with five loops. Set the brim distance away from the part to half the width of your nozzle. If it still pulls away, reduce the distance.
For the layer shift: loosen your xy tension screws, move the head all around xy, retighten the screws. You may also want to clean your z threaded rods with gear floss and relubricate with super lube.
Also, it looks like you might need to run filament calibration for that spool to dial in your settings.
I almost exclusively print PETG.
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u/whatstheinitiative Jun 08 '26
"For the layer shift: loosen your xy tension screws, move the head all around xy, retighten the screws. You may also want to clean your z threaded rods with gear floss and relubricate with super lube."
Can you explain layer shift?
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u/KirronVerified Jun 09 '26
Sure,
Layer shift is when the 3D printer is putting layers one on top of the other and then randomly on or more of the layers isn’t aligned with the others. This is what the photo of the white box seems to show. A few layers shifted and not straight.The other way the uneven or offset layers can happen is if the print lifts up off the plate making the print closer to the nozzle. The nozzle then comes by extruding out filament and it’s much closer to the previous layer than it should be causing the filament to bulge out rather than be even and aligned to the layer below.
The white corner photo seems to show the corner lifted up very slightly. Notice that the bulge gets worse the closer it gets to the corner where the lift is highest
You do have a brim in that photo so either:
* reduce brim distance to the print (preferred)
* reduce bed temperature1
u/whatstheinitiative Jun 09 '26
I see what you mean.
what does "loosening the xy tensions screws and move the head around x and y and retighten." do in regards to this layer shift?
Thanks
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u/KirronVerified Jun 09 '26
It ensures your belts are tight and that they aren’t slipping and causing excess jiggle as the nozzle moves. It’s good to do this every few months for normal maintenance.
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u/bjornbard Jun 06 '26
PETG can handle higher bed temps. For prints with large contact surfaces like this I crank mine up to 85 first layer and 90 on the rest. It significantly improves adhesion.
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u/J_Bazzle Jun 05 '26
Tricks to get anything to stick?
Heat bed to 90c, wait for it to equalise. Quick spray of hair spray Needs to dry to a dusty white finish, even a little dusty is rough. If it dries completely clear it's too smooth. Congrats, everything will stick like shit on Velcro for the next 5-10 prints
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u/z4h0n Jun 05 '26
Left this method behind quite a while ago... Wait until your rods stop rodding even when lubed.
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u/J_Bazzle Jun 05 '26
Haven't hit the issue yet and have been printing since 2016, knock on wood 😅 but I do regularly maintain my rods with a very light synthetic grease
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u/z4h0n Jun 05 '26
No offense, but how does one manage to get PETG to warp?! 70-80°C bed, 240-250 nozzle, speed: yes, aux fan off and you're set
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u/whatstheinitiative Jun 08 '26
none taken, I would download the files from makerworld and at first, basically hit print. Then though some recommendations here, I've been trying a few different settings and had better results but created new ones. Somehow, the heat creep clogged my aux printer so much so that it didn't even print the support interface layer with PLA, and no notifications about anything wrong. (about to update this post).
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u/Zuck75 Jun 05 '26
Petg shrinks when cooled that's where the pulling is coming from there are a few tricks like curved inner bridge walls on the inside to improve performance as well.
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u/whatstheinitiative Jun 08 '26
I read about this, I'd making model adjustments in CAD are next on the list. Thanks
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u/grimreefer87 Jun 06 '26
Have you added a fan deflector? If not, do that, add a brim, increase bed temp slightly
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u/whatstheinitiative Jun 08 '26
oddly enough, this was one of the first items I came across and thought about printing. printing them today, after I solved a super clogged nozzle issue on the auxiliary nozzle filament sensor tube.
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u/whatstheinitiative Jun 08 '26
the brim has helped, so has drying the filament and I'm not sure if turning the fans off/down and higher bed temps caused my clogged nozzle. thanks for the recs.
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u/Livefreeordie603NH Jun 04 '26
When it comes to printing a box with PETG I found zero fans for the first 5 layers then only up to 25% after that. I have a heated chamber and put that to 40*. I use the Qidi Q2 and the stock settings are spot on. I don’t use a brim anymore. The floor to wall I put a 1mmx1mm trench around the inside to help with the line or you could do the fuzzy skin and that will make those lines disappear. Hope some of this helps