Report courtesy of drone dj
Ideal for the Karen’s to complain about now stealth drones looking at my property to rob😂
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Somewhat annoying that there aren’t more clips of drones flying with these propellers with the sound on (e.g. the very final shot). 
On the flip side, annoying as it may be, surely when operating near people, making a noise is a good thing, from a safety point of view. (c.f. electric vehicles)
Anyway, I’m off to print some and see how it goes. Or not. I only have TPU and PLA, and neither of these make particularly good props.
And while my brain’s on this track, if it’s just about tip vortex, how much of an effect would simply adding an outer ring have on the sound? Like these old things:
Of course, that adds more weight right at the worst place, requiring more power and probably making it more likely to be unbalanced.
I wonder if they would work on fullsize aircraft and helicopters, though I guess they’d need to figure out how to make them variable pitch
They’d certainly be of interest to the scaled up drone air-taxi startups. I’d imagine the manufacturing costs (and R & D costs) would be an issue though.
Adrian
I bet DJI would sanction them.
And MAS would manufacture them 
I very much doubt it.
I had to search to see if this had already been mentioned. A different article on the same subject. I only flew my first drone (a DJI Mini 2) just over a year ago and was surprised at the noise level. It would be good if Toroidal props take off, no pun intended.
Guy turns one into a PC fan
Someone else trying them
His first attempt with PLA was less successful 
I cant see these being anygood for freestyle or racing due to the extra mass and the fact that alot of that extra mass is toward the outer edge of that props. I would like to see someone like Chris Rosser test these props on a proper test rig. Im sure it would show a reduction in responsiveness on acceleration and deceleration due to the extra mass and higher point of inertia. Maybe theyre quieter and maybe more efficient for long range and casual flying but I wont be jumping on the hype train just yet 
Latest update with some pseudoscientific app measurements.
He seems to have opted not to compare the results on his video. 
I’m wondering if that’s because there’s absolutely no discernible difference in sound level or quality between the two.
Then there’s this guy, who thinks the whole thing is some sort of hoax. (I confess, I couldn’t stomach him for the entire video.)
How to fly your toroid’s… 
Not the best, but getting there. I mean, who uses 4 blade props?
(I think I’m done with these now - need to get something different in my YouTube feed. 
)
I notice the normal prop is pulling around 3A at max thrust but the Toroidal prop is pulling almost twice that at 5.8A at max thrust
Has anyone heard of these supposedly highly efficient and quiet propellors being developed by MIT?
Does anyone 3D print them yet?
Will DJI add them soon?
Cheers.
Moved your post to a thread about said propellors
And check below ref 3D printing
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