# 3D Printed Air Vents for a Waiex

Discussion in 'Workshop Tips and Secrets / Tools' started by FritzW, May 12, 2019.

1. May 13, 2019

### Hephaestus

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Actually home SLS systems are getting close to ready for prime time. FDM carbon fiber nylon is super strong and has a great look.

2. May 13, 2019

### ScaleBirdsScott

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Home SLS is pretty cool, but we're still not at a point where the volumes can do larger parts, and for the costs I think it'll have to come a bit further where the printable volume to cost ratio is really in alginment. If I just need to make figurines and handheld small parts it's great. But ya won't be making large stuff from SLS on $1000 machines for some time still I think. (Though I have seen some cool stuff using DLP projectors and so that might turn the game a bit eventually. I could see low-medium resolution large-scale printing being a cool option down the road. And FDM carbon fiber laced Nylon can work really good. I'm familiar with the Markforged machines which do this using the ability to inject chop or continuous filament into the print bead. But aesthetics wise the Markforged is still FDM, so still nowhere near an SLS or fused nylon in terms of the final part finish. But no-matter whether it's a$500 home FDM machine, or a $500,000 industrial unit, whether ABS or some crazy material, good design that works with the printing process can make useful parts that only a few years ago just weren't in the cards. That said I guess my point is, if you only occasionally have a select few parts that you want really good quality from, investing in fancier and fancier printers may not be a winning strategy for some time. I've been down the road and I've decided that a cheap FDM printer using ABS is good-enough for my homebrew needs, and if I need better than that, to go to print services. In a few years once the home-game options have gotten better and there's some consensus out, then I'll be re-investigating what that base home printer is. My point is that there's always going to be a new machine around the corner, and I don't want to be the guy spending$2000 for a machine that in 2 years will be worse than a $500 machine. I did that with FDM back when the Replicator 2 came out. Got good use out of that machine but my$500 printer runs circles around it in most cases.

So instead I figure spend the $40-100 per part and get the best quality the industry has to offer. For example, on 3D hubs, to get the same machine-gun end caps printed that I had, would cost$89 for one, or $134 for both out of the same HP Fusionjet nylon process. That's about what I paid from my local source. Now, I used a home FDM to print full-size mockup parts and test the fit and look, because I diddn't want to spend$90+ to get something and find it doesn't fit. But it was night and day visual compared to the final parts.

Last edited: May 13, 2019
3. May 13, 2019

### Hephaestus

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I'm planning on adding an opensls style k40 build here soon.
J
to start learning the process - hope the metal DMLS or whatever they call it this week is within it's realm later, I think I saw something about doing some lower melting temp metals in it possibly with argon added to the chamber.

4. May 15, 2019 at 3:07 AM

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Prusa i3 mk3 user here. Paid about \$800 for the kit version when it came out and have had it for about a year. Haven't done any major maintenance after putting it together other than scrape off plastic that gets stuck in random places and I've run 20+ of plastic through it. It's accurate enough for me to print threaded holes, though they do need to be run through once with a tap for fasteners to go through smoothly.

My favorite filament by far is PETG. It sticks great to the bed, bridges gaps easily, has a silky finish, and sands easily. Being a close relative of polyester, you can easily bond it using MEK based solvents and higher end superglues (I use Locktite). It's mechanical properties put it just below Nylon.

By contrast, both PLA and Nylon are famously unbondable and unsandable. PLA is also rather brittle and extremely sensitive to UV. Tried a couple times, but I've never been able to dial in settings for printing in Nylon despite having a heated bed and enclosure. It won't stick to the build surface unless it has a layer of glue stick (PVA) on top of it and I a lot of trouble with layers debonding. That and it rather aggressively absorbs water, which really degrades its mechanical properties.

Never did any tests, but from youtube mechanical test videos the fibers in the carbon fiber filaments don't really add strength, though they add a lot of stiffness. Being chopped fiber, they also embed themselves into skin if you handle the prints often and are somewhat of a hazard. Clean up also takes awhile as you need to scrub off the PVA glue. In contrast, for PETG prints, I just snap off the parts from the metal plate and clean it with alcohol; I can usually start on the next print within 5 mins.

The cons for PETG are its low temperature resistance and its low modulus, especially if you combine the two. It'll flex quite a bit before it breaks though.

Design-wise, if you print is greater than 0.25" thick and has a 50+% fill, it should be tough enough to be handled daily. That and and avoid loads under elevated temperatures.

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5. May 15, 2019 at 4:31 AM

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You think PLA is unbondable? My 80" span Corsair is entirely printed from PLA in many small sections that are glued together with CA. It's been flying successfully for a year so far.

CharlieN likes this.
6. May 15, 2019 at 4:57 AM

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Interesting! Did you rough up the mating surfaces to get a better bond? I've always found CA/PLA superglue joints to have poor mechanical strength. Got a far better bond from "welding" parts together with a soldering iron and extra filament.

7. May 15, 2019 at 12:06 PM

### Tantrum1

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I like the vent! How do I get one! lol

8. May 15, 2019 at 2:52 PM