That’s curious, about the red filament. And thanks for the detailed response. I appreciate it.
Comment on Filament quality
dual_sport_dork@lemmy.world 6 days ago
You can generally trust dodgy rolls of ordinary PLA. For anything with special properties like sparklies, purported fiber fills, a metallic sheen, etc. all bets are off. You are equally likely to just find yourself with a spool chock-a-block full of randomly sized nozzle clogging particles of who knows what, or a roll of what turns out to be perfectly ordinary boring PLA and a set of product photos with a high degree of Photoshop polish.
I likewise don’t trust knockoff spools of engineering materials like Nylon, polycarb, etc. at all. Food for thought: Polycarbonate at PET in their natural states are both startlingly transparent, both are bendy-bendy, both have near identical melting points, and are equally annoying to print. PET is significantly cheaper than polycarbonate, though. So guess how easy it would be to spool up 1 kg of PET, slap a label on it that says “polycarbonate,” and sell it to the unwashed masses who are by majority unlikely to actually whack any test samples of the stuff with a hammer? Et. cetera.
So it is likely to be with purported PLA blends like “tough” PLA or “pro” PLA or “plus” PLA from the no-name brigade. These are often just regular PLA with a 30% markup.
Never forget the time honored Chinese pastime: 能骗就骗.
And this is going to sound stupid, but specifically beware of spools of nameless red filament. I don’t know if it has something to do with the pigment they use or what, but the only spools of any material I have consistently had embrittlement issues with have all been red.
Maerman@lemmy.world 5 days ago
dual_sport_dork@lemmy.world 5 days ago
Yeah, I have no idea what’s up with that. The first time I didn’t think anything of it, the second time I thought it was an odd fluke, the third time I was looking at it quite askance, and the fourth time was with a spool of red ABS rather than PLA which did the same damn thing despite three other spools of other colors from not only the same brand but even the same package (it was a 4x250g sampler pack) and that made me mighty suspicious.
It’s still usable if you handle it carefully, but the end of the filament tends to snap off in storage or during handling, i.e. when loading and unloading it from the printer. Cooking it in the filament dryer doesn’t seem to result in much of a change on that front, either. I have no idea how this affects the final mechanical properties of the printed part, but I’ll bet you a dime it won’t be a positive impact.
SaveTheTuaHawk@lemmy.ca 5 days ago
Just to add…avoid any carbon fiber doped filaments, they are proven weaker and those carbon fiber fragments are dangerous to breath or touch.
dual_sport_dork@lemmy.world 5 days ago
Yes. If I absolutely must use a fiber filled material, I prefer glass fiber rather than carbon. A fiber fill in your filament reduces shrink and warping and increases rigidity, and makes some tough-to-use polymers more printable such as Nylon. However, the above is correct in that it reduces tensile strength and especially layer adhesion strength, i.e. tensile strength along your Z axis. (Plus, carbon fiber fills basically always limit your color selections to black, black, and black.)
If you need mechanical strength of some type or another, it’s almost always a better idea to use a non-filled filament in a more suitable material and work on modifying your printer or getting a better printer that’s capable of printing that material. I can do straight polycarbonate in my machine with a pretty high degree of success (other than very small parts, I’m finding) so in all honesty I don’t have much use for fiber filled filaments anyway.