Testing MIT's Toroidal Drone Propeller Design & Sound  

Very interesting!!! Thanks for the videos!!

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Viewers must realise that quite often there is automatic audio processing which makes the quiet sounds louder and the loud sounds quieter to even everything out.

Everything up to the "heavily modified" part was made clear in the video. Hopefully the MIT lawyers won't come after you. With no comparitive run of straight-bladed props, these did not jump out as quieter. I'm sure the acoustic devil is in the details-even the slightest variation can affect the results.

Lmao lmao lmao

More like a swarm of bees.

Lower frequency tho

To be honest, this guy can't get the propellers smooth enough, balanced enough, or uniform. In other words, he's not good enough and doesn't have the proper equipment to make the design good enough to actually work right.

@@iCantEvenButtonsGaming did you really just say "perfected propellers" 😭😭

Are you saying my man's 3D printer ain't up to snuff?!

Yeah the real ones are trash too, they just muted the sound in the video for their demonstration unlike his

@@ITX-EcoClass yes

He said he modeled it himself, so we don't even know if he modeled it properly. In the paper, they specifically designed the shape to interact with the vortices it generates. It looked like the middle of the blades were thicker than in this video. This guy didn't even pronounce toroidal correctly.

​@@jamiepierson7772 you would know

they are made for boat impellers LOL inboard jet motors

they are meant to put out 2x the pwer with 1.3x the sound this guy is an idiot

​@@cantan111 They're literally intended for use in drones to make drone based applications easier to be accepted in residential areas.

The design really looks like an improvement overall

Thinking exactly the same

@@oslier3633 are you trolling? or… just not very smart?

​@@oslier3633 the 3d printer isn't precise enough, it looks accurate but small flaws mean a lot at high rpm, the stock blades are very very purpose made, despite technically being an inferior design

@@jameshenderson4094 MIT used 3d printers. Also, precision just improves efficiency by a few percentages. This thing just sounds louder.

Residents of Kyiv can hear drones louder.

One of the problems is this person almost certainly does not have a 3D printer that would be capable of the precision needed to actually make one of these propellers to function correctly, these theoretical propellers take advantage of very specific fluid dynamic properties, so if you don't get the design almost perfect then they're completely useless,

WAIT YOU YOU ARE A MOD FOR JAKERTOWN

😂😂😂😂

i live on kyiv and that made me wheeze​@@user-fy8nd6nz5w

In other words they need to be molded not printed

100%

The shape causes cavitation to occur in the whole length of the blade instead of the tip, which reduces the energy of shockwave produced which makes a quieter sound

It was mostly notable at higher frequencies as well.

The toroidal propeller was also explicitly designed to be 3D printed, which was the method they used initially to create it. I feel that depending on how you design it, it probably can account for the turbulence from all the rough edges

🤣🤣🤣🤣🤣🤣🤣

3d prints are not aerodynamic. This test is completely bogus and pointless

It doesn't hit the same frequency peaks, and they'd have to test actual decibel level to determine that but it does sound slightly lower. The main difference is this is a hobbyist trying to recreate something he saw without all the necessary data and equipment to do so. The design and tests MIT have done have shown a much larger decrease in sound. But beyond that, this design is simply more powerful. It pulls in a much greater volume of air.

Well, how do we know that? We need a comparison video

Beads?

Sounds like hornet chase. 🤣🤣🤣

This joke reminds me of that one trajedy... whats it called? Norm Macdonald?

Its actually suppose to sound like a military helicopter

Have it drop black/yellow marbles.

To me it looks like the outer geometry of the props isn't anywhere near what is currently under development. He's getting waaay too much turbulence by the sound of them

ABS and acetone smoothing might work well.

@@conorstewart2214 Exactly what I suggested on another of these videos.

From what I recall the official design isn't actually out yet for use, can't remember. So it's probably a custom build that only looks the same. Probably why it's having turbulence.

Automatic audio compression is one hell of a thing. You never know if what you heard was how loud it really was.

Ikr, why not just clear coat it? Like from an airbrush or simply an aerosol can.

​@@JPtheGamer650I'm guessing the nail polish lays down thicker to fill in the layer lines. Smooth finish.

If I print stuff with PLA or ABS that needs to have a better surface or be made stronger, I coat the part with Plastruct Plastic Solvent Cement. It's a very thin liquid that melts the plastic a little before it quickly evaporates, making the part sturdier and prevents it from layer separating.

@@walkingweapon lays down thicker and dries quicker! hahaha I know things like this are born in communities for a practical reason, but at the same time it baffles me how consistently I'm seeing/reading instances of "smart" people doing "dumb" things without critical thinking or research - you know, using the intelligence that got them to that point to begin with, haha. They just _trust_ and awkwardly bungle through it. It feels like the same thing as watching people struggle with opening packages/unboxings or figuring out how something works, they're all fumbling impulse and no thought to _think_ and problem solve. I mean absolutely no disrespect to the guy making the video or anyone else, I admire expression of passion. But they're kind of like that one friend most of us have that are *always* closing car doors too hard, hahaha. They aren't _feeling, thinking, and reacting appropriately in the moment,_ they're just bad instinct/forethought from moment to moment. I don't understand how people can be so intelligent and interested in tech fields yet be so oblivious to physical reality. Anyway, I don't 3D print, but still speak from personal experience in expressing consistent dissatisfaction from trying to work with nail polish when thinking it would work for that exact expectation of smoothing out. I can't imagine that the added weight and globby imbalance are helping things after applying it with the nail brush in such short, stabby strokes like that. It may be a viable solution for impatient people working with small parts, but I have a hard time believing it works at all for this application. I wouldn't be too surprised if these issues contributed to the excess noise heard in the video. After the heat treatment, I presume that responsible application of a spray-on gloss coat would yield a considerably lighter, more even coating that wouldn't glob up to mess with balance and intended air effects of the design. Speaking of: the design he used and the design he showed are very different at the tips and it's killing me lol

loudest drone in the ends

😂

Loudener 🤣

"Loudener" genius 😆😆😆😆

“Erharera to test it out”😂😂

He wanted to compare right? So no these arent quieter

@@Deathblow85He wanted to compare the designs, yes. However, the manufacturing method for the two designs was radically different and involved different methods, materials, and levels of refinement. If you want to actually compare the two designs to see which is louder you need to use a decibel meter and you need to properly manufacture the blades, which includes a lot of fine tuning for balance, smoothing, and blade edge shaping. As other have also pointed out, the toroidal blade is likely not 100% accurate to the design it’s based on simply because the specs haven’t yet been released. Even a small inaccuracy can make a huge difference in things like this.

He also failed to mention they made many different variations and are still testing it.

​@@Deathblow85He wanted to directly compare the designs as the only variable. He couldn't, so the results don't matter

@@mightymarlin97 so i think you actually understand, gratz! The test was broken, because he tested an trough and trough developed design with a not so tested one, and home made at that. So while I applaud this video and its creativity, the comments below it justifying the difference because of the materials used etc. Mean nothing to me, because it was like testing a round rubber wheel, versus a wooden square one.

Do you ask purposefully pedantic and rhetorical questions? 🤔 He showed himself 3D printing it ya goob lol 😄🤦🏻‍♂️

@@Vikanuck you missed the point while you were deciding which cute little faces to add to your reply. he kept using those words "their propellor". we all saw him print it, friend. the point was where did he get the model he printed? because he made it sound like he just made something that looked close and went with it. you probably found this video informative.

​@@Vikanuck"do you ask purposefully pedantic and rhetorical questions?" Based on the available evidence, no, they do not. You might want to use a dictionary more often, friendo. There's nothing rhetorical about the questions they asked. And, given that the topic of discussion is aerodynamics & engineering & combined sciences & their real-world application, where it is necessary to consider and examine the minutiae and small details in an academic & scientific manner, what they asked was rather non-pedantic. Acquire a dictionary and incorporate it into your life.

maybe because it was built with the wrong materials and techniques?

Its not really louder. It's just a deeper tone vs a higher pitch. Would work better with diff materials and bigger, thinner loops

Who cares?🤓

@@AmAzingshortssz the point of these propellers is that they are supposed to be way quieter, which they aren't. Do you own a functional human brain?

@@EthanJahnz i dont👍

@danny supersell have you heard of the triforce?

Have you heard about our lord and savior postal dude?

Have you heard of the high elves? Oh what am i saying, of course you haven't.

"Loud" propellers: Now we FLY! "Quiet" Propellers: WE WILL BATHE IN THE BLOOD OF OUR ENEMIES!!!!

Have you heard the tale of Dath Plagueis the Wise?

Unless your aiming is on point 😁

Hahaha

yeah mit is trying to help kill a lot of people.

@@hellcrow539 aim wont matter if theres a swarm of them 🫡

Lots of ammo required

Or print the toroidal props out of ABS and acetone smooth them to get a very similar finish to the stock injection molded props.

​@Conor Stewart isn't that what he did? The nail polish remover is acetone.

@@maksrambe3812 he didn't say he removed the nail polish

this^. a control would make this test way more useful

​@@maksrambe3812the hell are you talking about nail polish is acetone? That's absolutely not true lol. Acetone is sometimes marketed as nail polish remover but I'm fairly certain a solvent wouldn't make the best nail polish

💀

Lmao true 😂

MIKE- 3d print a giant rose stem and lower yourself onto it, friend.

AYO 😭

🤣🤣🤣🤣

They sound frequency is lower so its quiter from the distance

@@thelespauldude3283 though the sound will penetrate walls better. One reason I like my props is that they are so high pitched even the slightest obstacle blocks a lot of the sound

it sounds cooler tho

if not louder~

@@thelespauldude3283 isnt it supposed to be the opposite?

Looks like you got a little more than you bargained for 😂

@@Oatskii Isn't that how it usually happens?

Carry a racquet…

My sympathy. You can wait until they calm, or evening. Pour a cup to pint of gasoline in the hole, and put a sealing rock over the hole. After several minutes you can light it if you want. Yellow jackets are gone, and nothing will hatch. I do this in the yard where I mow, not in the woods. Don't light the hole around dead leaves.

🤣🤣

No. Don't use nail polish. How do you even picture a uniform application of it using a brush?! Better use a spray coating of whatever brand, you'd be able to achieve a result much more uniform than that.

Swarm of bees are much quieter after they sting you to death

Honestly it’s not hard at all to replicate something on a 3D printer

Not that impressive, especially when he did it so crudely, which made the props even louder

@@Jordan-rb28 you must be a lot of fun to the parties you're not invited to...

@Mikeyp0131 the world's filled with people who like talking about how something could be done, or worst, how easy it is to do this or that, but there are far fewer people who DO the thing.

@@kuzadupa185 thank you! IOW, anyone can be a critic…..

😭😭😭😭😭😂

🙄

Sound like a fly near my ear

Which is impressive since he built an inferior version lol Now imagine what it'd sound like if it was made properly?

Low frequency sounds travel further than high frequency sounds...actually.

@@sunvetr that's why my stepdad thinks he's not deaf now lol. He can only hear the low frequency sounds. He has the hearing ability of a tree.

That’s what I thought, but it could have been just sound compressed differently. He should measure it properly.

The problem is that it's a rough, 3D printed propeller vs a smooth, manufactured propeller. It's not a fair comparison at all.

Well of course they are Albert Einstein, they were 3d printed lol.

It’s crazy stuff. Spilled some at a Boy Scout camp once and paint thinner was not cutting it.

That was surprisingly interesting considering the topic, Cheers

😂😂 yooo I’m weak

That's pretty much been the case every time I see these. It just cuts the high end noise down so it isn't such a piercing whine.

But thats because the making of it is not perfect. Not only is the design simply a guesstimated imitation (MIT did not release the proper dimensions and specs), the materials and manufacturing of the wings are also not the same (which can have a massive impact on something like aerodynamics).

There is another video on the ‘Tube where someone compared the frequency spectra of the stock prop to their toroid - the toroid appeared to have reduced some of the more irritating and difficult upper frequencies. There was no correlation between reduced noise and flight duration, implying reduced drag or energy usage. I’d like to see how a toroid prop increases range/endurance, climb rates, max altitude…these types of thing.

I also think the new propeller design made less noise (even while being 3D printed), the video is misleading because the microphone normalizes loud noises, and if it's loud enough, it'll clip, which it sounds like the first one did.

or simply set it to hover & time how long it takes to fall out of the sky.

The main advantage is the fact its designed to be 3D printed, and is more efficient. The fact its 3D printable alone, is good enough for me. That unironically opens the doors to alot of stuff

@@honkhonk8009 I could see how it would be fun to tinker with, but fail to see how it's more efficient when the only difference in operation was the noise level. And it has a larger surface area without being much thinner so it's not more efficient unless the actual performance is better, which they didn't really seem to touch on.

3dB increase is double the perceived sound

The outer geometry looks waaay off...

the real propellors were literally 3d printed too

@@tee1532But there was also a great deal of time, effort, and money spent to produce machines that could refine that 3D printed raw product to be a smooth and properly balanced blade with the desired chord and AoA. Besides putting nail polish on his homemade ones, there doesn’t seem to have been anything done to rebalance and actually smooth out the blades, let alone actually working to ensure the specs matched the actual design in lengths, angles, chord, etc.

they're quieter from further away, they produce less high frequency soundwaves from the normal ones

The MIT design is quite a bit more efficient, when perfectly balanced/smooth/designed/etc.. The lessened sound is mostly in the middle of human speech, so the range estimation frequencies aren’t touch.

You want goosebumps just think of all the children a silent drone could bomb.

@@XiaolinDraconis drones don’t need to be silent for that. Just drop a bomb or rocket from high altitude and they will never know the drone is there. Or just use munitions that go over the speed of sound, you wouldn’t hear it coming either. Stop with the scaremongering around drones it is ridiculous.

I think the point is not for recreational drones but more for commercial or cargo usage. Like if you are using a drone to record an event or to survey a building or carrying cargo, you would want it to have the least impact on people around it so reducing its noise is a good idea.

@@conorstewart2214 yeah but traditional drone bombings don't capture that delicious close up of the terror on their faces the second before the blast.