Continuing the discussion from 3D prints for SOTA (Part 1) - #100 by EI3LH.
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Continuing the discussion from 3D prints for SOTA (Part 1):
You need hardened steel nozzles for filaments containing glass fibres, as they are very abrasive. For standard PLA and PETG, normal brass nozzles will work fine.
It’s a good idea to keep some spare nozzles on hand, as they can clog due to dirt or debris in or on the filament.
73 Heinz
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PLA is generally thought to be the most forgiving material to use, but PETG isn’t really any more difficult.
Allegedly. I have been printing FT817 covers, and PETG was significantly less stiff, and could be broken with less than half the force of PLA.
PETG is nothing like PET.
ABS is harder to work with, but mostly stable in UV.
A lot of ABS parts I made simply lost strength and failed, with or without outdoor UV, within a few years. Filament ABS != Lego ABS
If you want seriously strong prints (engineering grade) you can get carbon-fiber filled PLA and PETG, but you will need an upgraded hotend (unless you go for a high-end machine which is already setup for using it).
I would dispute “seriously stronger” based on published data, and snapping a cover. Somewhat stronger would be more accurate. Allegedly less warpage, and the '817 covers printed beautifully in carbon PLA on a Bambu. Look fantastic too. Pity I need them painted bright-zinc silver not black.
If you want “seriously stronger” try nylon. This is what happens when you bring a pick axe handle down hard onto a sample part.
Plain white PA6 nylon parts have been going strong outside for 6 years now. You do however need a continuous design that can be printed in nylon, as any gap will be bridged by strings. The Bambu has been unable to print ASA or PA6 so far, as the shrinkage pulls them off the bed, seems a heated enclosure will be needed,
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I was trying to give a more simplified approach.
There are alot of factors which affect material performance, including initial design and stress concentration, in-fill pattern and density, wall thickness, material suitability for the purpose to name some.
You are right that PLA is more rigid than PETG, but this also results brittle failures once overload is reached. The flexibility of PETG makes it significantly more durable and impact resistant.
Printing with Nylon really requires an enclosure and a good quality heated bed and not something I’d recommend a newbie to try at first.
I find this site is generally informative about the different materials, as well as a good beginners resource in general: Ultimate 3D Printing Materials Guide | Simplify3D
Cheers,
Dave.
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Gotcha. So using the hardened ones is really just overkill on PLA and PETG?
Learning so much from this thread and everyone’s real-world experience. Thanks all.
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Brass is best for non-abrasive materials. For PLA and PETG, it’s better than steel because it transfers heat more efficiently. Only use steel nozzles when printing abrasive materials.
73 Heinz
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Another one for the printing ToDo list. Shame it won’t work in 2025 though…
If you know, you know! 
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