I print a lot of PETG, and I’ve been playing with temps and other settings. The phenomena below happens a little bit on certain filaments but lately its happening a ton… I’ve been playing with the fan curve but I can’t tell if i’m making it better or worse, or if it is un related.
Anyone know for sure?
The more I look into this I think my speeds may be a tad too high, which is causing the nozzle to not keep temps up? I’m going to try raising the temps slightly and slowing everything down a tad more and see what happens.
Nope… not the speeds. I’m stumped I don’t see this when printing pla… but is has been getting progressively worse over time. is that belt ripple?
I see this pattern on peoples prints online, especially with silk just not nearly as bad as me.
Ok now I am VERY confused… I made just a cone to repeat the results, same setting… and this problem is no where to be found on the print…
I’ve done about 5 of these spools and each one seems worse. WHAT THE HECK IS GOING ON???
Sorry but… does anyone have any ideas? It’s giving me an aneurism trying to figure this out. The fact that it doesn’t do it on some prints is really bugging me…
It seems to only happen on thick walls. The spools, and this print someone designed for their basement pipe at work I am doing. Thinner walls don’t have the effect… again it has be cooling related but I don’t know if its too cool or too hot…
Running Creality CR PETG at 255c, 70 to 73C on textured PEI plate. Like I was saying on other prints I don’t get this issue. I assume its too hot but… for PETG 255 doesn’t seem very high.
I have: tuned all my filaments (many times)
Tightened all the hot end screws front and back
Ran all calibrations.
tried every config of temperature and fans.
it’s weird!
No irony, no sarcasm… maybe this is a problem…
Explanation - I recently started using a new brand of PETG and I like working with it, so after many “default” prints, I decided to fine-tune it and did a Flow Rate Calibration. It went OK… I set the new correct value (according to the calibration - I did it about 5 times repeatedly - still the same result).
However, the actual prints were worse than before with the “uncalibrated” filament… I don’t know why. Anyway, now I have two profiles for that filament, and before printing, I decide whether to use the “regular uncalibrated” one or the “tuned” one… and 90% of the time I choose the “regular” one, and the results are OK or more exactly Better. With some things, the difference is unnoticeable, but with others—especially larger ones and those on vertical walls—it’s simply visible (which is why it occurred to me when I saw your photos).
Maybe some people will say that I misinterpreted the calibration results… yes, that’s possible… but in order to get the value that works for me in reality, it’s simply not possible to be wrong… during calibration, the value is completely off… in reality, it’s OK… I really don’t know why…
So just a tip “out of the box”… maybe your problem isn’t in the cooling… but somewhere else?
Wish you luck in your “quest”
Which calibration are you referring to? Flow rate or pressure advance? I used to use my calibrated pressure advance, but never noticed much of a difference between the calibrated results and the stock results. I suppose it could be that! I’ve tried less and more flow too, seems to like being slightly on the low side.
Thanks for the response by the way!
PETG loves water and is very susceptible to showing moisture effects. Comments like ”lately it’s happening a ton”, “getting progressively worse”, and “don’t see this when printing PLA” all fit perfectly with higher humidity recently if you’ve been printing well otherwise.
It may not be water but if you look through posts here people have all sorts of issues with PETG HF and get talked into replacing belts, extruders, nozzles, etc and still have issues.
How are you drying your PETG? How do you store it? How’s your humidity been? Have you updated firmware or Studio recently and does that align with the changes in print quality? If you haven’t updated things like that between everything working and now not working there is no need to roll back.
my petg lives in one of my two filament dryers, and my dry box is at the minimum my hydrometer will read (10%) I don’t get a lot of stringing, no popping or vapor coming off it. My dry box is a gasket lid plastic box. I doubt its moisture I do a lot of TPU so i’m well versed lol.
The apartment being the winter is under 20% in here ambient. I use a creality PI and a sunlu s2
I think I figured out a solution… sounds weird but my results speak for them selves.
Looks like these are VFAs caused by the seam, been printing thick rings to re produce issue.
My temperatures had to drop, and my fan speeds had to drop quite a bit that minimized it.
My phone camera is REALLY struggling to photograph these rings (intended to imitate the center of those filament rolls in previous images)
ring 1:Standard temps, horrible.
Ring 2:Reduced temps and fan, much better but still bad.
Ring 4: tried changing the fan 3 times throughout print, cleans up when fans are at the lowest… but still not great.
Ring 3: Changed my seam position to nearest BOOM, problem gone… Inside of my ring I have two spots as show in the picture below… but the results is muuuch better.
It sounds like you’re good. Not all are though.
Thanks. I work in a production plant and even though I have purchased desiccant… we also have barrels of massive bags of it that I take home sometimes, I toss it in there.
Seems weird this issue…. I don’t get this with TPU or PLA. I hope there is something else I can figure out as I do not want to be stuck with this seam position with any thick round print going forward. setup a PETG profile for “seam nearest” just in case lol.
I’ve made a weird discovery… Makes sense though.
The faster I run print speeds, travel and accelerations the less these VFA’s happen.
My reasoning when you run a brushless or in this case stepper motor slow, you can feel each notch… when you move them fast that effect is reduced.
Just did another test, the higher I put up the acceleration the less VFAs I had… not PRINT speed.
This is counterintuitive.
guy on the right is at full speeds even with increase max flow rate (probably a little to fast) on the left are the slowed down pieces… there is even VFA on all the infill… this is odd.
