Even within a single type of FDM filament there is an overwhelming amount of choice. Take for example Elegoo’s PETG filament offerings, which include such varieties like ‘Pro’ and ‘Rapid’. Both cost the same, but is there a reason to prefer one over the other, perhaps even just for specific applications? To test this, [Dr. Igor Gaspar] over at the My Tech Fun YouTube channel bought some spools of these two filaments and subjected both to a series of tests.
Obviously, the Rapid filament is rated for higher extrusion speeds – <270 vs <600 mm/s – while the website claims a higher required nozzle temperature that confusingly does not match those listed on the spool. There are quite a few differences in the listed specifications, including the physical and mechanical properties, which make it hard to draw any immediate conclusions. Could you perhaps just use Rapid PETG and forget about the Pro version?
Test objects were printed with a Bambu Lab P1P with an AMS unit. After calibrating the ideal temperature for each filament, a tensile break test gave a win to the Rapid PETG, followed by a layer adhesion test win. This pattern continued across further tests, with Rapid PETG either matching or beating the Pro PETG.
There are only two advantages of the Pro version that can be seen here, which are less moisture sensitivity and stringing risk, and you of course get the luxury cardboard spool with the closed edges. Whether that’s enough to make you go ‘Pro’ remains to be seen, of course.
Just started my second spool of Elegoo Rapid PETG (transparent) and is a very good PETG obviously if you want the “glass” effect you can forget the Rapid part of the name. But both at low speed and high I can’t fault it. No stringing, excellent fluidity and really tough.
I’ve always avoided the high-speed PETG variants just because of their low heat deflection temperature. Seems barely better than PLA. I guess it would make sense if you’re using PETG mainly for its mechanical properties and don’t mind keeping everything indoors.
PLA has completely warped sitting in my car while PETG did better. Shrug
Don’t get me wrong, PETG in general is great. It’s just these “high speed” variants that tend to have HDTs around 60C or so, which isn’t much better than the ~55C you get from PLA.
I’m amazed at the extensive testing he’s doing.
His content is always information heavy, he’s that kind of guy, less of an influencer, much, much more of an educator/solid information giver.
Well here is a thing – the mentioned 270 and 600 mm/s is not “extrusion speed” it is “printing speed”. Why do suppliers specify max movement speed? For me, it was always somehow more natural to think about movement limits as a property of the printer (how fast i can go without causing unwanted artifacts) and than for filament to limit flow rate – or how much plastic can i safely melt per unit of time / how fast i can push the plastic through the hotend.
because the first number is a general number for standard settings, 0.4mm, 0.2mm layer height usually, although higher speeds may also be achieved on lower layer heights etc.
But the proof is usually in the pudding, it’s what your machine can handle at the settings you want to use vs what the filament can do. And that will be entirely dependent on many things, like your melt zone volume for instance, which to a point, most people should be aware of through max volumetric speed testing.
Like I know that my machine(s) hotend can all cope with a minimum of 23mm3/s with standard settings, so around 300mm/s but whether the filament can do better or not is entirely down to testing at the settings you choose :-)
in the last paragraph of this article it finally said something i wanted to hear :)
in the comments on a different article, someone mentioned “taulman 910”, which i looked up and it’s apparently a nylon+ sort of filament. and the manufacturer has all these claims about its strength, as do the reviewers. but i found a review that said “easy to print”, “prints like a dream”, “Absolutely zero warp. None.” “80mm/s”, “I have almost never had anything bridge better”. and that kind of talk got me excited. the only other sentence i would have liked to see was “no stringing.”
personally, easy to print is my #1. i feel pretty happy that i’ve solved by bed adhesion woes with petg (wash the bed with soap; increase bed temp 5C at a time until success) but i’d have just as soon had a material that is well known to be always stick when it should, and release when it should.
i found a pla that was easy to print and i was really sad to see every single object turn into brittle garbage. so the material qualities do matter in the end. but i hate experimenting with other filaments. i want something that’s decently tolerant of humidity while it’s on the spool, that prints well over a wide range of temperatures or at least pretty reliably at the temp written on the spool, that doesn’t string too much or tolerates retraction, that sticks and releases, that bridges alright, preferably not too stringy.
iow, a petg that doesn’t string so much as it absorbs my basement air definitely interests me more than one that’s 20% stronger.
and if you google any of these filaments, you’ll see on the forums, what people are talking about, is these “ease of use” things. why does it string? why doesn’t it adhere? what do i need to do with temp / fan / enclosure / drybox? that’s where the meditation should be :)
I used rapid PETG, my only negative is that it’s a bit glossy