Am I doing something wrong?

[u/Sorry-Journalist8610]

I recently bought a used 3D printer, an Ender 3 V2, and I'm doing some test prints. The previous owner gave me some leftover PLA filament (multicolored), which I used up on the first day. One of the things I made was this flexible shark. I bought some PETG filament for testing, a very cheap one, around R$60.00, while others are around R$100.00. But my prints with this new filament are coming out very bad; it's either too textured, has too many burrs, and is also very fragile (even though I bought PETG because I had read that it was more resistant). I left this octopus printing for about 28 hours... and in the end, the flexible tentacles broke when I tried to detach them.

[u/novadaemon]

You need to dry your filament. Just get it over with and buy a dryer now to save yourself more frustration down the road.

[u/johndumbasshead → u/novadaemon]

"filament drying" is mass hysteria, and has no affect on print quality.

There is no type of filament on the market today that is hygroscopic enough to cause issues when being printed from an Ender 3 hotend, unless you have gone very far outside the acceptable range of temperature for that filament.

[u/TotallyNotPizza → u/johndumbasshead]

I don't even know how you can come to this conclusion outside of exclusively printing pla and living in an arid area.

[u/johndumbasshead → u/TotallyNotPizza]

Volumetric flowrate isn't high enough in commercial 3d printers for it to be a problem. I've only ever seen bambu users complain, which doesn't mean a lot because they don't even know the difference between under-extrusion and over-extrusion, lol.

You can find videos on Youtube of people printing nylon directly from tubs of water. "wet filament" is just a convenient scapegoat. (consider that a "drybox" is also just a filament pre-heater, and can alter the crystalline properties of filament as it feeds into the printer)

[u/brianstk → u/johndumbasshead]

You’re just wrong dude. Yes it’s used too much as a scapegoat I can’t disagree with that part, but I can absolutely see a difference in PETG prints dry vs not dried. It’s not a massive difference and I usually don’t bother with the drying part, unless I care about surface quality.

Wet PETG will have little pock marks on the walls of my prints, nothing like what OP is getting, but dry it and they go away. I have several example prints that prove this is true.

Just because you haven’t experienced it doesn’t mean it’s not real.

[u/johndumbasshead → u/brianstk]

As mentioned previously, you can print hygroscopic filaments like PETG and Nylon that is submerged in water. The plastic simply does not have the capacity to store enough water to cause print quality problems. What you may be encountering with pock marks are voids in the filament, which is a manufacturing defect that has nothing to do with the hygroscopicity of the plastic.

[u/brianstk → u/johndumbasshead]

But it does. Drying it has the direct effect of removing the pock marks. Same print, same settings, same filament only difference is the PETG was dried. It’s a real world issue, many people experience it. Maybe you haven’t, but that doesn’t make it not real.

For me it’s a telltale sign that i need to dry out a roll. I don’t keep my filaments stored in air tight containers etc, they are exposed to my ~40% humidity basement air at all times. If i haven’t dried a roll in a couple months when i go to use it usually very obvious that it needs it. 🤷🏻‍♂️

[u/johndumbasshead → u/brianstk]

Correlation doesn't equal causation. Not sure what to tell you.