3d printed EDF help!!

[IcedStorm777]

Do you know if there in anyone on the forums that could make the planes for a 70mm EDF? I am hoping to be able to 3d print one but don't have the skills to design one. I figured they might be able to design it around an cheap but good motor. Maybe from hobbyking? Thanks!!

 

[tanyoon]

Have you tried Thingiverse? I did a quick search and saw a few options, though since I've never worked with EDFs I can't speak to the design quality.

Are you wanting to print the impeller as well as the housing? I've played around with printing 8"-10" propellers and had pretty mixed results. I don't know if I'd trust a printed impeller at the required speeds for EDFs. Either way traditional FDM printing might have trouble with the tolerances required too, SLA/DLP (or even SLS or other industrial grade machines if you have access) would be much better suited and would give you a much smoother surface finish but I would still question the structural integrity at such high speeds.

I'm not saying it's impossible or that it won't work, but if you do find a design and try it please take proper safety precautions when you test it. That's a lot of energy to be putting into possibly brittle plastic.

I'd probably suggest buying a proper injection molded product from HobbyKing or the like.

 

[jhitesma]

SLA/DLP tends to be weaker than FDM despite the higher quality surface finish - the resins are usually pretty delicate and brittle. Even things like spinners on normal props can be really tough to get reliable prints that don't fly apart and those tend to be lower RPMs and stress than the impeller on a EDF.

Like Tanyoon I won't say it's impossible...but I haven't seen anyone pull it off and testing it can be rather dangerous.

Best bet would probably be to use a printed part to create a mold and then cast it with some high strength casting resin if you were determined to make your own. But that wouldn't be very economically advantageous as that kind of casting resin isn't very cheap and tends to come in larger containers....might be worth it if you plan on making a lot of of them - but for a one off you'd almost certainly be better off just buying one from China.

 

[Sebastian Hoepfner]

Do you know if there in anyone on the forums that could make the planes for a 70mm EDF? I am hoping to be able to 3d print one but don't have the skills to design one. I figured they might be able to design it around an cheap but good motor. Maybe from hobbyking? Thanks!!

I am currently working on creating and testing an fully printed 70 mm EDF. My idea is to use PLA for all the parts. My goal is to have an 11or 12 blade impeller to create a whooshy therefore less noticeable sound instead of the screaming 6 or 8 blade sound.
Of course it will be tricky to cope with blade stability issues at high rotation speeds.
As well there are thermal issues causing PLA to get soft at temperatures over 50°C.
And the material surface is some topic of concern since even with a z resolution of 0.06 mm there are noticeable steps which create turbulence, therefore reduce performance.
However, early attempts show that the blades come out nicely balanced.

Other than that, the mechanical blade and duct design (blade angle of attack, blade profile, number of blades, ... ) is a wide chapter. Luckily there is lot of documentation out there.

So after all don't expect much useable outcome, this is just my little experimental project. I am happy to share files as soon as I see results somehow satisfying.

Best Regards