The Genius of Cycloidal Propellers: Future of Flight?

[@ZirothTech]

Thanks for watching, it's been great to learn about a technology that is both mature and new in two different applications. Don't forget to get started in Onshape for FREE: Onshape.pro/Ziroth​ - You won't regret giving it a try!

[@alihyari7358]

Thank you for the quality content. I am disappointed in the lack of details on the thrust, as the title kind of led me to believe that it has much higher thrust to weight ratio but the video did not cover that in detail.

[@1islam1]

​@@alihyari7358🔴 What Is Islam? 🔴 Islam is not just another religion. 🔵 It is the same message preached by Moses, Jesus and Abraham. 🔴 Islam literally means ‘submission to God’ and it teaches us to have a direct relationship with God. 🔵 It reminds us that since God created us, no one should be worshipped except God alone. 🔴 It also teaches that God is nothing like a human being or like anything that we can imagine. 🌍 The concept of God is summarized in the Quran as: 📖 { “Say, He is God, the One. God, the Absolute. He does not give birth, nor was He born, and there is nothing like Him.”} (Quran 112:1-4) 📚 🔴 Becoming a Muslim is not turning your back to Jesus. 🔵 Rather it’s going back to the original teachings of Jesus and obeying him. More .....👇 🔴 THE RETURN OF JESUS

[@Freja_Solstheim]

Onshape seems to be an easy way to "lend" peoples designs..

[@Cineenvenordquist]

​@@richfromtangYou're being silly thinking flying cars should be entraining bugs and detritus in their airflow, but need to be more critical when it comes to tires/landing gear because abused rubber turns to inhalation and IgE hazard rather than smol bouncy toys. So far? There's probs the flight Design (where's the arχiv for this) for kinder kitten footed landings and wheel adaptations...

[@CoincidenceTheorist]

10:10. Return to the airship. Use them on that

[@mayday-nl8565]

My parents owned a small passengership that was sailing on the rhine that had a VSP system from 1936. It was one of the very first production VSP in the world. It ran for 70 years before it finaly broke down and we could not get the parts anymore.

[@usaturnuranus]

"Ran for 70 years before it finally broke down..." as I'm in my 60's, I can tell you that this is a better track record than several people I have grown up with.

[@comfortablynumb9342]

​@@usaturnuranusI started losing friends when I was 21 and they've been dropping for the last 28 years, it never gets better

[@comfortablynumb9342]

I'm surprised nobody would make you the parts. I'm sure someone can, it's a matter of price.

[@usaturnuranus]

@@comfortablynumb9342 I hear you. Sometimes I feel like the last man standing.

[@JoeStoffa]

How big are the parts? Sounds like a perfect application for 3D printing with wax resin and investment casting some aluminum bronze (if it were me I'd pay to keep something that unique running, but YMMV).

[@Gribbo9999]

When I was a small boy back in the 1950s I was given a small, cheap plastic toy aircraft that had horizontal rotating wings. I don’t think it had any power, source you just threw it and it glided a bit with the wings autorotating . I'd forgotten all about this little toy of nearly 70 years ago until I saw this upload. Thanks for the memory!😊

[@joefish6091]

In engineering and science, schools too, brilliant minds are usually beaten into submission and towards consensus thinking, no new ideas please.

[@gen865sol]

I also bought a styrofoam toy rotating wing kite, held against the wind by a string bridle at the ends of the rotating axle. They were sold at the Dayton Air Show

[@williamwalker39]

That toy worked using entirely different physics for lift, called the Magnus effect, the same effect that makes a baseball curve. The savanious shaped wings could rotate along their central span-wise axis, and the oncoming wind caused the rotating wing to generate lift. These could auto rotate to the ground if the wind stopped, so it acted like a parachute. The vehicle in the video works on an entirely principle, and generates lift in effect by flapping its wings in the rotor like a bird. This vehicle can not auto rotate to the ground if the motors stop.

[@TheLandbo]

I remember a similar toy from my boyhood days, however, it was designed so that it flew like a kite ie. it was tethered to a string. It was sometime in the mid-1960s.

[@Samsjunk]

"I have to wonder if it offers any practical advantages" uhh yeah man, me too. That's why I watched the video. Little disappointed you didn't answer that question.

[@ZirothTech]

The advantages are the thrust vectoring (and noise reduction), which is why it can be useful in marine applications (and the others I mentioned) - but I personally think it may not add much advantage in practise for aviation. These are still really awesome propellers, and I'm sure the design of them will help other fields. Sorry this wasn't the conclusion you wanted!

[@WillyK51]

What about using them for wind generated electricity?@@ZirothTech

[@FilosophicalPharmer]

@@WillyK51Excellent idea but fairly certain they exist already.

[@ameunier41]

In theory having the entire length of the blades at the same speed offer better efficiency, but you lose a lot because parts of the cycle isn't producing trust.

[@MegaLokopo]

@@FilosophicalPharmer They have been found to be far less efficient than traditional wind turbines.

[@eaaslee]

I’m glad there are still people with the vision to say ‘I know we have a system that works but I want to try a different approach’ this is what we need to advance. Also when you commented on the quieter operation you didn’t mention military applications, I would think they would be the bigger backer of this.

[@Dang_Near_Fed_Up]

Had the Wright brothers accepted what was "known" as 'fact' about propellers, man likely would never have left the ground. Always question what is accepted as fact if you want to succeed as an inventor. I would think the VSP would be very interesting for submarines as well, since it is quieter by it's very nature over a standard prop.

[@jamesheal1615]

@@Dang_Near_Fed_Up Given others also had a working aircraft, we would have, no issue.. But I hear ya, someone has to think outside the box.. That how we got axial flow turbine engines and.. Shutter... Wankels...

[@Dang_Near_Fed_Up]

@@jamesheal1615 The reason I mention propellers and the Wright brothers is that what was accepted as fact was wrong, pitch angle and thrust output were WAY off. The Wright brothers discovered this. Using pre Wright Brothers data, lift would have been insufficient for manned flight, but adequate for drones / lighter vehicles as had already flown. Given the limited engine technology of the day. It was this discovery that put the Wright brothers in the air, while experimenting in the back of a bicycle shop on a laughable budget. While everyone else was failing to achieve flight on huge budgets, and with entire machine shops doing their builds.

[@sclabhailordofnoplot2430]

Advance yawn it’s my sky paddle boat. I was just bored.

[@davidlewis5742]

@@sclabhailordofnoplot2430 And what is the value of your teenage reply?

[@commonwombat-h6r]

Thank you for mentioning the downsides of cycloidal rotor propellers as well

[@johnluffman7954]

Downside: Low efficiency, complexity, bulk structure

[@MyrKnof]

@@johnluffman7954 I was thinking the extra gear to control the pitch would have to eat effeciency.

[@LoganKearsley]

Another minor benefit is that having a horizontal rotation axis makes it easier to balance torque with a variety of rotor configurations.

[@johnnyswatts]

Don't standard propellers and jet engines also have a horizontal axis about which they rotate?

[@LoganKearsley]

@johnnyswatts If they are providing horizontal thrust, yes. But with thrust parallel to the axis, you don't have the freedom to alter the direction of angular momentum however you want. The only options are putting engines in pairs or using control surfaces to provide a counter torque. Which is why you don't see many 3-rotor drones.

[@absalomdraconis]

​@@LoganKearsley : There are actually 3-rotor drones. They're rare, but you just need to tilt the third so that it cancels it's oen torque characteristics.

[@erichpizer1]

I love onshape and refer many people to it as an experienced solid works user slash engineer. I also worked for Voith and yes the schneider propellar opened my eyes when we installed two on tug boats for navy in simons town south africa. I also got to play with the simulator . it was fun

[@qoph1988]

Probably the first youtube sponsor that got me.

[@euansmith3699]

"Yeah, but, aside from Safety, Efficiency, and Operational Versatility... What has the Voith Schneider Propeller ever done for us!"

[@johnransom1146]

Python reference noted

[@James-yv1dl]

Bridges!

[@euansmith3699]

@@James-yv1dl😆

[@fryncyaryorvjink2140]

Brought peace?

[@TheBoozeCruiser]

​@@fryncyaryorvjink2140 Oh, peace!? SHUT UP!!!

[@mspicer3262]

I've never wanted flying cars, or if I did, I grew out of it fast enough to not remember. I've worked in insurance investigations, and know all too well how people drive cars that stay on the ground. Flying car accidents will be next level... EDIT: People saying that helicopters and private planes are like flying cars, no. No they are not. A helo-pilot in Canada has to pass four exams, get a medical certificate, have 40 hours of ground training and 45 of flight training, just to get a license. requirements aren't much different to be a fixed-wing pilot. A driver's license doesn't require school. You have to pass a vision test, a test on knowledge of traffic laws/signs, and pass a road-test.

[@ravenmad9225]

Yeah,personal flying vehicles are pretty much a none starter. Too many things can go wrong to make it safe.The authorities would never allow it.

[@somethingsomethingsomethingdar]

I still want one…. For me buuut not for anyone else 😂

[@shaynejudkins1605]

Not only has it already "started", but Alef Aeronautics has alrrady sold 3,000 (preorders for) its upcoming (2 seater) "flying car". It's probably safer than autonomous cars, to be honest.

[@billyoung9538]

Most of the current flying car prototypes will never qualify for the flying car "road" systems I've heard being talked about. The current prototypes will be more of classic aircraft and likely be required to be registered and flown in similar fashion. Aka Airport to airport or helicopter landing pads; however, the proposed flying car roads will require the vehicles to be almost entirely point and click. The user will be far more of a passenger and less of a pilot. The reason for this is very reasons you're talking about. With the density of air roads people would be unable to navigate effectively without potentially running into one another thus computers will have transponders that communicate between vehicles and if any of the safety mechanisms like the transponders or engines malfunctioned then the flying car would literally land itself or prevent itself from taking off. There is also talk of putting in redundant engines so that if a quantity failed the vehicle would remain airborne and able to get to a place of maintenance for repairs however it would not be allowed to fly to other general purpose locations until repaired. Again the goal behind the discussions and logic for this is to try and minimize the dangers imposed by unskilled individuals.

[@jimk8520]

People will have to get pilot licenses to operate in the airspace. Those who don’t qualify won’t get a license. In the end, how is this going to be different than the private pilots who fly today?

[@juliane__]

One of the best information channals i know of without diving too deep into the topic.

[@ZirothTech]

Thank you! Always try to find a good balance 😀

[@alfabsc]

Thanks for explaining this technology. I learned more than I ever knew about marine propulsion using cycloidal propellers. Love your sense of humor.

[@JamesStripling]

I love the idea for propulsion and steering on an airship. These mounted on a gymbal to transit from horizontal for lift and propulsion to vertical for steering and propulsion. Brilliant! The flying car is a stupid idea. It always has been. Most people can't drive on the ground; try texting and flying. Forget to put this on the charger and you aren't walking home or pushing it to the nearest charging station when the power cuts.

[@joshpatton757]

We already have flying cars - they are called helicopters. There are several good reasons why they aren't replacing land based cares.

[@CeL-w2p]

We hand out licenses faster every year that passes. When stationed in Germany i did like the 100 questions per test you had to pass. The unit i was in had a clerk that passed after 8 times. Anybody who knew her history wouldn't get in the vehicle if she was driving (fixing stupidity impossible). Can't wait for self-driving cars, no speeding tickets, where's the state, county... going to get all that free money to piss away. 😂😂😂

[@absalomdraconis]

​@@CeL-w2p : There's becoming a question about if we'll actually see true self-driving cars. That may be limited to self-driving flying cars in the future (mandatory self-driving thereby becoming the difference between a flying car and all other flying vehicles).

[@absalomdraconis]

If you think you want to use cyclorotors for both horizontal and vertical flight then you don't gimbal them around, you just stick them at a relevant angle in the first place. Stick two in a V configuration, and the only thing you have to worry about is rotations around axes that don't run through the center of the V (which themselves can be dealt with through other aspects of the vehicle design; non-rotational movement can already be handled by the V). Stick three in a Y configuration and you don't have to worry even about those two axes. Break the rotor segments into separate sections with the same power axle and you get even more control options.

[@werepat]

Check out the Cyclocrane. It's a huge cycloidal propeller supported by a helium blimp.

[@HunterCadre]

Ah hey its the video on Voith-Schneider mentioned in the comments of the previous propeller video! So cool to see someone covering cycloidal rotors and discussing the applications in both marine, airspace and renewables! With renewables, a future video topic may be wind turbine designs? Aside from the typical horizontal axis three blade wind turbines you find everywhere, there's a lot of companies trying to find new ways of doing things. There's a lot of work trying to make small-scale wind, but in large scale as well. Particularly in offshore floating wind a lot of unusual large scale designs have been proposed, since it is the an immature industry that needs cost reductions and radical thinking the most

[@LuciusKyrus]

Renewables are bullSh!t. There is no such thing. It's a complete scam. The energy is used during operation or it's loaded on the front end during manufacturing. There is no free ride and that's the big scam about renewable energy.

[@motopaulo]

I enjoy these ziroth explainers! Good science content with the boring stuff trimmed out. Excellent!

[@JD_Mortal]

They need an exterior brace to reduce the need to "suspend" the spinning blades freely. It will also provide better potential air-control. Blades can actually be setup to "pull in" on all blades, and direct air outward for turning, through holes in the exterior braces.

[@jackimo22]

8:54 *that dude has nerves of STEEL*

[@malcolmabram2957]

A difficulty I can see with a working VSP system for flight is there are more moving parts and greater scope for failure. It is one thing for a ship to fail, but quite another thing for an aircraft in the air.

[@albertharvey3477]

Too many parts. Parts brake, while flying. End of story. Albert Harvey Rotary Engines

[@jonathanmacdonald9609]

Flying vehicles already have tons of moving parts. Look up how a normal chopper works and what a swashplate is. This could, of course, still be less reliable, but it's always better to have something where you can tell when it's wearing out and fix it than it is to have something that breaks less, but it's gonna happen sometime. (not saying that's this, just one reason you can't base all of engineering off of one rule) ​@albertharvey3477

[@Erowens98]

Not to mention the fact that drivetrain complexity usually adds weight. Which is very costly when you're designing an aircraft but ships don't really care too much about.

[@stonerscancatch]

Have you ever heard of a whole aircraft parachute? It's a great way to make manned drones safer

[@Avalanche-Ice1950]

Decades ago, I handled the Navy's two Voith Schneider Water Tractors (little 1,000-hp bathtub toys -- but they served very well in the Philly Shipyard!) I also got to check out Foss Tug in Seattle, which had some stellar VSWT's (BIG-engine tugs!) Fantastic for moving ships and barges, and delightful fun to handle!

[@myaschaefer6597]

My kids and I love your videos! You're a librarian of genius ideas, engineering, and emerging technologies! Cheers!😀

[@jafo49]

I was inside Dr. Keletch's rotor ( probably spelt wrong) back in the 80's two weeks before he attempted a flight. Eye witnesses said it got off the ground about a foot before before the attempt was stopped. The design had a propeller at each end of an elongated egg shaped fuselage with T mounted horizontal blades at the end of each blade of the propellers.

[@winklethrall2636]

I played around with this design decades ago, back when the materials for making a flying version of it were not available. I ended up making a desktop fan and stopped at that.

[@takingbacktheplanet]

lol. i wasn't thinking of using it to trim hedges or lose an arm as potential usages when i saw the Jetson One, but it does look cool :) to each their own!

[@lauig]

Man, love your content. Always appreciate the deep dive, research and the mentions on drawbacks or questions yet to be fully answered. There's one Engineering topic that would tremendously help you understand and then maybe convey to your audience why some of those promising technologies take so much longer to even start to get adopted. It's called Dependability Analysis (gross english translation) or Sûreté de Fonctionnement in it's original French as this originally stemmed from the french Military Nuclear and then Aviation programs that were under a certain level of Secrecy post World War 2 (and based, off course, on a ton of previous work from many more origins civilian & military alike). It's the engineering task of assessing how and why any partial-system can fail and then how the greater complete system would respond, which safenets or redundancies can or should be put in place to ensure the system can still function and/or safely recover. Here if just one of the four cycloidal propellers fails, the whole unit falls down and crashes minimum safe net would be the addition of a parachute. On the jetson craft if one of the 8 motors fail, the 7 others can compensate to ensure a slow descent. If up to 4 of them fail but with each on separate boom, almost same thing. if 2 of the motors from the same boom do, you can shut down all others to initiate a descent with the blades on autorotation. Recovery is still possible. You'd descent a bit faster but still hopefully in non-lifethreatening fashion. On a classic plane all engines can completely fail (which they rarely do) and you can still glide down to safety. One very good exemple of that Dependability topic and it's application was what happened with the Tupolev copy of the Concorde that was actually flown before the Concorde but crashed miserably. Russian spies had managed to steal the Concorde frame plans and had it built in a very short time just to "win the race". The engineers of the Concorde in France and of Bristol Engines in the UK, through their own xp and with the help of those Dependability/SDF thorough analysis had become the best experts in the world at managing vibrations, especially those caused by the engines. They perfectly knew which frequencies had to be favored and which others had to be eliminated at all costs (through materials, designs adjustments, dampening featurs etc) for the whole frame to be able to endure not only the flight constraints from the exterior on supersonic endeavours but also all the inner constraints caused by the very powerful engines themselves. The russian engineers did not possess such fine knowledge, know-how and assessments and that's why their frame shattered on the first presentation flight which ended in a disaster crash.

[@NicholasRehm]

Cool overview video, saw a few cyclos I built in there!

[@ZirothTech]

Your builds are some of the best I've seen for sure, super impressive work I left your video in the description, but I regret not mentioning it in the video. It was really amazing to watch

[@GabrielDevenyi]

How about trying to build one of these! patents.google.com/patent/US9623960B2/en

[@apocraphontripp4728]

The solution is obvious. A fixed design, with all the trust downward. Then run it like a regular drone. Now, with the thrust fixed downwards, a ducted design can be used, increasing thrust. Should be fairly easy to build, removing all the unnecessary pitch garbage. A bike hub motor should have the Rpms and torque to run one of these. Thanks for the vid. I'm currently building a 1 kilowatt hand held laser. I might try this next.

[@KarrierBag]

Sitting on my boat watching, wow, would love something like this, mine is sea going as well as rivers and larger canals here in the UK.

[@absalomdraconis]

Bear in mind that for high speeds conventional screws are more desirable. The higher the desired speed, the higher the wear on the components, so the higher the maintenance burden of cyclorotors. I'd even say that at some point, you'd be better off with a little pair of electric auxiliaries fixed to a board that you could hang off the back when you're getting close to e.g. a dock or something.

[@Erowens98]

You'd probably be better off with an azimuth thruster pod setup instead. Simpler and thus easier and cheaper to maintain.

[@mellissadalby1402]

Good point about the noise reduction. In ocean going ships, propellor noise has been identified as a factor that is causing harm to cetaceans, who use sound to navigate and to hunt.

[@Maverickib]

As a helicopter pilot, I can't help but think a major drawback to many of these eVTOL designs is their inability to autorotate/land safely in the event of a drivetrain failure. I'm all for innovation and I hope they can crack the code and make something revolutionary, but I feel it would be easier to convert a mature technology like helicopters into easy to fly EVs than to convert drones into people carrying EVs. Take a helo, give it an electric drivetrain, fly by wire/pilot assists, folding blades, bam, flying car that can land safely if the motors lose power and has a mature understanding of flight characteristics.

[@Randy-v9x]

These innovations will likely, one day in the not too distant future, revolutionize small boat racing. Incredibly exciting. Thank you

[@marion-bs3qh]

I'm going to be the one... ;0) The plural of 'aircraft' is also 'aircraft' because 'craft' is a collective term. Incoming in 3 ,2, 1...

[@donaldvincent]

You are one smart kid. I love to see young "science nerds" do well. Your presentation was well researched and explained. Stay curious. One new subbie for you.

[@0005yuki]

so your telling me, the goose plane chap was onto something. Crazy stuff. Great video as usual ziroth!

[@Eidolon1andOnly]

*you're

[@AquarianNomadic]

​@@Eidolon1andOnly *yore

[@JackParsons2]

​@@AquarianNomadic *Ur

[@defeqel6537]

@@AquarianNomadic Yor Forger?

[@jaredkennedy6576]

Watching tugboats with this drive system work really shows their power. When they turn sideways and start pulling back on the rope, that's impressive.

[@kingmasterlord]

riverboat airship GET! i want one of those amazon zeppelins with this out the back

[@TrueBigfoot]

Love the humour at the end, cutting hedges and losing an arm 😆

[@docyoungblood9521]

9:28 "Flying cars have been a childhood dream..." in the 60s they taught us that flying cars were a sure thing by 2000! :D

[@absalomdraconis]

The only thing stopping us is that we can't trust the users with them, so we need the Air Traffic Control systems to be able to give them orders... and the ATC systems aren't ready for that yet.

[@defeqel6537]

@@absalomdraconis not really the only thing, cost and practicality are still very poor

[@FredericoKlein]

it's so cool to see this. I had a problem a while back and kept thinking of a design like this to solve it. It is nice to see that something like what I was thinking actually works

[@onerian8178]

i dont think people have fully realized how much of a nightmare flying cars would be.

[@icarus313]

Very interesting design and thanks for the cool introductory video to all the key concepts at play here. I wasn't aware of these kinds of rotors/propellers before.

[@victoryfirst2878]

THESE ARE USED ON LITERALLY MOST NEW TUG BOATS. REALLY TRANSFER THE POWER TO THE WATER ZIROTH. 😀😀😀😀

[@atomicskull6405]

It's not new they've been used in tugboats since the 1940's

[@victoryfirst2878]

Thank you Sir for jogging my memory brain cells. You are correct @@atomicskull6405

[@jeffbybee5207]

​@@atomicskull6405been used since 1870s is navy had a small ship with the both type replacing both the screwprop and the rudder

[@brianpesci]

I could see these being a possible solution to having smaller scale wind turbines. Very cool.

[@absalomdraconis]

I think there may be a few wind turbine versions.

[@defeqel6537]

We have had those for decades already, their benefits are operation in less and more windy conditions, and area (to some extent), but their downside is that they capture less of the energy

[@johnransom1146]

Would like to see more about this in renewable energy

[@ZirothTech]

I'll do some research and see if there is interesting things for a future video 😀

[@tonychan647]

@ZirothTech how is this different from vertical wind turbines? That same question came up right away. Lol

[@Cineenvenordquist]

​@@ZirothTechI think you mean searching, if you're not funding 6 grad students, designing a slate of experiments, and maybe someone gets a PhD if it publishes higher than MDPI. (I mean, maybe one would get you footage and bake you a cake, I don't know.)

[@christianjunghanel6724]

Also the "Graf Zepelin" germanys only aircraft carrier which was never completed , was also equiped with such propeller atop of conventional ones!

[@karstenschuhmann8334]

Something like this would have saved the Bismarck. It would have allowed to reach a safe harbor despite a broken rudder.

[@1zaj34]

For me, the most obvious downside of that design for aviation is the lack of lift in case of an engine failure. A helicopter retains the ability for autoration, which in many (most?) cases provides enough lift for an emergency landing and a plane still has wings. What would happen with a cycloidal propeller?

[@Rotorhead1651]

"plane fall down go *BOOM*!"

[@jamesbruce7595]

Not really knowing anything about this, but I would suspect it would autorotor like a helicopter as well. it is just 'wings' moving through air.

[@joefish6091]

Deploy an emergency airframe parachute as some light aircraft and ultralights do now when SHTF.

[@julianopappalardo29]

Lots of friction for air use, yet. But, still quieter. Thanks for the content!

[@echohunter4199]

When I was 16 I came up with a design to use rotating drums with lifting surfaces installed that generated lift and thrust economically and was installed at the leading edge of the wings in a recessed form so the air flow would still have a modified laminar flow then thrust outlets were mounted towards the rear of the wing in small pods. This would generate enough thrust for shorter take off speeds as well as being able to generate more flow over the wing generating lift and the engine could shift thrust amounts between thrust and lift generation as it transitioned from takeoff to max forward thrust as needed. I’m not saying it functions as a VTOL design, just a more compact design that can support different structure configurations allowing new designs and allow for more power.

[@szsenyuk8887]

That propeller would be great for blending smoothies 😊

[@claytronico]

an idea I've always been fond of is a static attack angle Darrieus style turbine. The static angle of attack provides a lift vector in combination with torque. The idea is to have a horizontally rotating structure that can lift itself in steady wind. This concept works as a two line kite that would for sure destroy itself upon crashing, landing at a minimum would be treacherous. Perhaps an expanded PP type design that holds together until it explodes could save the parts and reduce danger, but the idea of a metal spinning death kite is pretty awesome.

[@frednewman2162]

Seems like they would be very vulnerable to bird strikes or icing issues if used on a plane!

[@owenwilson25]

Not sure which image is more surreal, the confused bird in the moment it's being drawing in, or the pilot after weeks of having to clean the rotors every day deciding he wants to sacrifice an arm.

[@skenzyme81]

The necessary materials science and control technology to making CycloRotors work are here. Check out the Hover Flight Dynamics for the new Bell V-280 Valor. Despite the small rotor size and huge power, Bell successfully developed full cyclic control of each rotor blade to maintain stable hover. If anything, the CycloRotor would be easier to scale, and given the strength and light weight of the V-280 blades, free-tip airfoils may be possible as well. As with the ABB Dynafin system.

[@antoniobragancamartins3165]

It hurts the Ockham's razor! Too many moving parts! Too many problems!

[@Ron_DeForest]

As opposed to the plains that drop out of the sky now?

[@TuukkaL]

Excellent video with fantastic, accurate and concise technical explanations! Thank you!

[@rthomp03]

15 years of development, and they've only been able to fly an empty carbon fiber frame with minimal battery capacity? Somehow I doubt they're on the verge of making a reliable man-rated craft. Aside from less rotor noise (normal propellers can also be optimized for noise), and lateral thrust vectoring (not that normal 4-rotor drones are lacking maneuverability), I'm not seeing many advantages here. There are several safety disadvantages (namely, if you lose power for any reason, you'll plummet to your death rather than having the autorotation capabilities of a normal propeller).

[@b43xoit]

I would say they could be made to autorotate somewhat, but not so sure the flare for landing would be possible.

[@rthomp03]

@@b43xoit The only way they could autorotate is if the control system controlling blade pitch was still working. But even then the air flow doesn't have much leverage relative to the center of rotation, so you'd get minimal rotation even if you were somehow able to decouple the drive motor from the rotor and let it spin freely.

[@b43xoit]

Agreed about control of blade pitch.

[@musikSkool]

As a general rule of thumb a helicopter/drone needs 2 times the lift necessary to hover. That way it can climb at a reasonable rate, and if it runs into a heavy wind it can still operate as it won't be overpowered by the wind and unable to choose its own direction. The worst winds are the downdrafts where the wind is literally moving straight down, toward a collision with the ground.

[@dingoniner5528]

0:17 - "But first, let's see how cycloidal propellers actually work..." followed by a history of their invention.

[@warren52nz]

This reminds me of a thing we used to do as kids. If you take a ruler (wood is probably best) and hold it horizontally with your thumb on the bottom and fingers on top, then throw it forward while pulling back quickly on the top bit as you let it go to make it spin "backwards" fast then it will fly across the room like a paper airplane. Different physics than cycloidal propellers but intriguing. I would have thought the downwards force would equal the upwards in my example but it does work.

[@bobcannell7603]

Thanks clear speech good research ten minutes ideal

[@wojtess8613]

explaining how it works starts at 5:50, before that it isnt worth watching

[@torstenkruger7372]

where is the 200% thrust part?

[@PaulSpades]

I guess, if you take the combined lift of the 4 airfoils they add up to 200%. At 6:20. I would argue you get around 50% thrust in this design, compared to a rotating 4 tip propeller with air foils of the same area. Maybe there's some efficiency gain from the uniform air flow, but I'm not seeing any numbers to quantify it.

[@ZirothTech]

This was referring to the old propellers from Cyclotech, as their new version has 200% the thrust-to-weight ratio. However, I now realise I didn't say that in the video! 😅I have changed this now to better represent the video! Thanks for the commment

[@swiftmatic]

I read, some years ago, that this tech was being used in some tugboats. It's power and directional capabilities were well above the standard screw-propeller with rudder layout

[@gEtar87]

0:40 All them Adolfs have the same look 👀

[@geraldbull9272]

Enjoyed this video, no hype just everyday down to earth explanation, wish I could do that.

[@Siderite]

It may be efficient, but my eyes hurt when I look at those.

[@ninehundreddollarluxuryyac5958]

An obvious advantage of a four cyclorotor craft is that the outer hubs of the rotors could have tires on them and also serve as wheels. It could drive along the ground when not flying.

[@b43xoit]

Maybe. The ground wheels would have to decouple from the airfoil rotors so the latter could produce enough lift for takeoff without propelling the former to ridiculous speeds, or so I feel (not an engineer in this field).

[@Matthew-bc9mr]

You would just need to have the aerofoils turn to angles straight on with the rotation to not create lift. And if the car driving dynamic performance got high enough, you could also have them turn in the reverse direction to generate downforce. And could even have it sense and adjust each corner to maximize grip of each tire. But... that would also mean adding suspension linkage that was locked stable during flight but compliant on the ground, as well as steering system that could also be locked rigid in flight. Adding alot more weight and tons of additional complexity.. not to mention battery life to drive after doing a flight... but who knows, maybe 80-90 yrs down the line 9f development as other technologies advance with it..

[@naramoro]

Can we let go of the "flying car" concept? It's a terrible idea and always has been

[@d.thieud.1056]

Please We don't want every traffic accident to be an aircraft. Cars ar problematic enough as-is

[@RFK_wait4_2028]

You're both right. And I absolutely am getting one as soon as I can afford it.

[@BennysThoughts]

The ability to do this has been around for quite awhile. It's a matter of making it practical. Now, obviously we aren't there yet, or we'd have them, but let progress do what it does and see where it goes.

[@792slayer]

I'd settle for aircraft costs coming down to used car prices.

[@roxasparks]

Theyre called planes.

[@mitchellminer9597]

Too many moving parts, too little area.

[@chrisbergonzi7977]

I was, literally, typing this and saw your post....good on you😊

[@hackembacker]

I hate it when people steal ideas I haven't had yet 😤

[@nickmalone3143]

Thats what boeing said

[@mhouslay7281]

Love your enthusiasm and the historical perspective in such a clear, balanced (oops - pun alert) and interesting video appraisal.

[@markmalasics3413]

Did you ever notice when a content creator with a severely limited vocabulary posts a video, the subject is always "INSANE"? So far I have seen posts about insane garbage cans, car designs, street signs, refrigerators, haircuts, bicycle propulsion systems, spacecraft, A/C power distribution, semi-automatic side arms, telescopes, cameras, vinyl record pressing, flashlights, seed planters, farm irrigation creepers, rain forest canopies, shoes, the statues on Easter Island, the design of the Pentagon, an ant colony, and everything else. I wouldn't suppose that the determining criteria for something to be "insane" isn't flailing it's arms, making over-animated gestures or being a danger to his or her self and the public.

[@Erik-oe7gc]

Just like everything is terrifying.

[@neilbush9873]

Yes i avoid anything" insane" although I fell for this one it having an interesting topic

[@remygrandemange8460]

What is insane is to write so much for such poor remark. 😅

[@markmalasics3413]

@@remygrandemange8460 If by doing so I reveal to the world more "brain surgeons" in the world, then it was all worth it.

[@remygrandemange8460]

@@markmalasics3413 It seems that you overestimate your influence and the "insane" level of your analyse ^^

[@js70371]

Having 2x playback speed is a great option for videos where you only need to get the gist of the subject to benefit from it.

[@XEONvE]

not going to fly... no pun intented

[@skindude9251]

Hey Ziroth, my first look at one of your vids and suitably impressed by your presentation skills and depth of knowledge. Nice one!

[@Vito_Tuxedo]

Use them as cycloidal propellors for VTOL then "feather" them into horizontal position to act as regular airfoils in a craft propelled by the thrust from a turbojet. The turbine could even have a power take-off to spin the cycloids when they're being used in VTOL mode. Whether that's any more efficient than alternative technologies that accomplish the same thing is the question that needs to be answered, but something like that is likely the best way to solve power to weight ratio issues.

[@butziporsche8646]

I sailed tugs with Voith-Schneider cycloidals.

[@20chocsaday]

A man told me about the test of two of them. On one of them the blades bent under test and should be strengthened. The other tug pulled the bollard off the pier. That was his excuse for being late. Oddly, no-one at university believed such a propulsion system existed.

[@bronson7130]

In Naval engineering school we were shown a film about a Tugboat modified with cycloidal propulsion. That was 1970. Haven't heard anything about it until now

[@gyrateful]

I thought this would be pipe-dream-click-bait video, but it is well researched. The historic and and maritime usage I didn't know about. Thank you.

[@BernhardSchwarz-xs8kp]

Thank you. It finally makes sense to me why windmills mounted on high towers are less efficient and in high winds - self destructive compared to Cycloidal Properllers.

[@Nevir202]

10:40 one thing I immediately see that might be a benefit of the cyclorotor over a regular propeller, is that in the event of spontaneous, unscheduled disassembly, the pilot and any bystander who isn't immediately ahead or behind isn't within the "blend zone." You could obviously protect the pilot by moving conventional props up, but any thrust vectoring puts you right back in the crosshairs unless they are REALLY high, and still doesn't protect bystanders.

[@christof.the.engineer]

I used to repair Voith Schneider propeller (VSP) Tugs in Africa. the maneuverability is crazy. Perfekt for Tugs

[@HenrikMyrhaug]

These seem virtually useless for flight, but I can see they are quite useful for maritime applications. Thrust vectoring for drone aircraft is simply done by tilting the aircraft, which allows an aircraft with a set of four rigid propellers to vector its thrust any (useful) direction it wants. Tilting the drone causes the forces on it to always pull an occupant be towards the drone's bottom, which makes the flight quite comfortable even if you are accelerating. The ability to further vector the thrust such that forces on the occupant of the drone would not pull them towards the bottom of the craft is really not useful for anything. For maritime applications however, where you don't want to or can't let the ship rotate, the ability to vector thrust in any direction is indeed quite useful.

[@atomicskull6405]

Spinning a pair of semi flexible wings around a hub so that they fly in place and controlling the angle of attack cyclically and collectively for altitude and directional control is a good way to do vertical lift. And on top of that the bigger you make it the more efficient it gets, unlike the competing solutions. And it's mechanically simpler than the competing solutions. That's the reason we settled on helicopters for this sort of thing. That's also why helicopters like the Mi26 and CH-47 can exist, the bigger and slower the rotor the more efficient it gets at generating vertical lift. An Erickson Aircrane's turboshaft has about the same watts output as an F35B's engine but it can lift 11,000 lbs in addition to it's own weight while the F35B in VTOL can just barely lift itself and needs a rolling start when fully loaded. EDIT this also one reason why we don't have full scale multirotors, a single large slow rotor is more efficient than 4 smaller faster ones. Full scale also requires use of constant rate variable pitch props (you can't really control thrust by RPM unless it's an electric system, turboshafts, piston engines or variable speed gearing systems would be too slow) and you end up with a machine that is more complex than a helicopter while also being less efficient at vertical lift. They actually built something like this in the 1950's called the Curtiss-Wright VZ-7, it used a central turboshaft engine connected by shafts to four variable pitch props and was stabilized by a three axis mechanical gyro system. It was said to be very easy to fly but it was mechanically more complex than a helicopter while also being less efficient and the program never progressed past a one man prototype.

[@MrAvant123]

Back in the early 70's before the Cleddau bridge was built in Milford Haven, the ferry known as the Cleddau King was fitted with voith-shneider props. It was a double ended boat and was very manoeuvrable.

[@pluss400]

Compared to a regular propeller, they have several disadvantages: 1. They ONLY generate LIFT DURING HALF THE ROTATION. 2. They don't have the huge surface area that generates lift. 3. In order to generate the same lift, there must be many of them which create an unnecessary complexity. 4. They obscure the vision of the pilot, which in a war situation is extremely dangerous. 5. Common propellers can be designed to be maximally efficient. A fun thing, but that's all it ends up being.

[@BobSutterfield1]

At 8:20 you say they don't create vortices and loud noises from the rapidly moving tips Any airfoil with a tip creates a vortex, as the medium spills from the high-pressure side to the low-pressure side To control that tip inefficiency some screws (marine) and propellers (aircraft) rotate inside tubes or ducts, and some wings have winglets on the tips And that's why some of your cycloidal demo clips show solid discs at both ends of the wings or a skid beneath the tugboat: as a fence to stop that vortex generation (The skid also protects the device from damage when it strikes the bottom of the harbor) But you were right about the noise, since a large diameter propeller's tips can move so fast they feature transonic flow, resulting in sonic booms A cycloidal propeller's wing uses the same airfoil profile across its entire span, rather than varying thickness and angle of attack along its length from hub to tip

[@handy335]

An excellent and informative presentation. Thank you!

[@yesthatbob]

At 30 seconds in, you mention the Russian engineer E.P. Sverchkov, who created his "Samoljot." That term is a transliteration of the Russian word for airplane, "самолёт." It is pronounced "samolYOTE." Whoever transliterated the word used a "j" to indicate the "y" sound in the third syllable. Russians are very practical when naming things. The first satellite to orbit the Earth was named "Sputnik 1." "Спутник" (pronounced "SPOOTneek") is the Russian word for satellite. Your video was fascinating, well researched, and well written and presented. Thanks. This is the first I've heard of this technology.

[@princeoftheblues]

I think this holds more promise in wind generators. They would have a great structural advantage because of supporting the blades at both ends. Plus, the lower speeds make it easier om the mechanism.

[@davefellhoelter1343]

in a way "I see" a similarity in rotor aircraft and a swash plate and/or collective-pitch. "I can see" how they could switch to rudders in maratime conditions with props for efficient propulsion over distance.

[@oM477o]

With conventional propellers you tilt in the drection of travel. It looks like you'd be able to control direction and attitude almost completely independantly with a cyclorotor. You could accelerate while remaining flat and level or you could hover while looking at the ground. very cool

[@trionghost]

Don't forget about two factors: P=v*T/η - there v depends on section S: v=sqrt(T/2*rho*S), and S=L*D - you should have big [L]ength and [D]iameter of cycloids to reduce [P]ower needed. And second factor is η - efficiency coefficient which depends on interference of blades and horizontal vortex produced by cycloids which both depends on D (closer blades = more interference, and bigger angular velocity which produce horizontal vortex). And these two factors renders this concept much less attractive when traditional rotors.

[@Key_Smasher]

Works much like a helicopter, and if any rotor fails, you have no wings to glide down safely with. At least a helicopter has some mass to sustain inertia on the rotor for a partially controlled decent. I think I'll stick with fixed wing planes. Replacing the screws for water vessels however is an interesting idea.

[@bschwand]

I remember 30 years ago Graupner was selling an RC model tugboat with Voith Schneider propellers

[@noreezy4991]

I remember seeing a video of this technology from that German or Austrian company developing drones based on these like 5 years ago and being astounded by how compact they were. In the intervening time I kept looking for examples of the technology being commercialized and nothing had come up. The original video also disappeared off the internet. I literally thought that it had been surreptitiously classified and scrubbed off the internet (yes, bit tinfoil hatty) or something like that, given how obviously useful and how much potential the technology seems to have.

[@luizfernandes6109]

Very well-presented video with the pros and cons of this propeller! It reminds the limitations of vertical-axis wind turbines (Savonius and Darrieus) versus horizontal propellers. As you mentioned, dynamic control of the blades is required to maximize efficiency, which increases complexity. However, there should be some benefits for some applications. Thanks

[@cyborg7898]

One major advantage not listed is even if it doesn't fly so great, I can use it as a backup combine harvester for my corn.

[@FOTPFan]

Just seeing the opening design it reminds me of a discussion with another engineer about autorotation in helicopters. (He's electric and mechanical, my focus was thermodynamics in ME while I continued to lean toward aerodynamics best I could at a school that didn't have those courses). I have some flight training completed, and I brought up the difference in "propellers" and the type of "blades" that rotary aircraft have, basically a wing that spins. This is an interesting application of that, but I worry about the added number of moving parts. (Then I remember adjustable pitch etc... on existing aircraft)

[@werepat]

Hey, it's a little late now, but you may get a kick out of the Cyclocrane, produced by Aerolift out of Tillamook, Oregon, USA in the early 1980s. My grandfather invented a rotating blimp that was a lighter-than-air cycloidal rotor. It was a beautiful machine that tragically failed, but there is a bit of information online and some youtube videos my dad uploaded relatively recently.

[@willcookmakeup]

Thats insane they figured out a way to make them swivel angle whilst rotating at the same time

[@BBQDad463]

The cycloidal propeller looks like it would be astonishingly complex. The vanes would have to switch their pitches twice in every rotation. I think there would be lots of wear. I think it could be made to work well if cost were no object.

[@geoffreystearns1690]

I recall that McDonnell Douglas experimented with using this configuration for wind power generation. Apparently it wasn't competitive against the tall windmill towers in vogue today.