This channel takes DIY to the absolute edge of achievment in a home shop environment. We need more in depth projects like this. Even if I don't build these projects, I learn so much that I can't stop watching.
This is fantastic and sad at the same time. I have rarely heard anybody explain things in such a clear, comprehensive and thorough way like he is. This is premium quality information for sure....and it has 203 likes. This should be reposted with a clickbait title like: how wings actually lift...finally REVEALED. Thank you.
You're welcome. Despite what many believe, physics is not hard, none of it. It's the maths that put people off and that's a shame. Take a look at our other videos even if you are not interested in lasers, I'll bet you come away with much the same impression. Our channel is literally exploding and many of these videos will be soon be seen by a much wider audience.
Funny you say that I am an Aero Engineer and I worked in Propellers 30 years ago , I haven't heard such an educated explanation except by a few of the old prop engineers, my college professors had no clue. This guy is good!
Best explanation of lift I've ever heard. I've been trying to reset my understanding since I learned Bernoulli's can't explain it fully, but was unable to find a good explanation. Thanks!
wow. just wow! looking at a propeler blande and finally understanding exactly why things are the way they are. Every piece of geometry on it has a reason. Nothing is random. And now seeing how i can even build it. That's mind blowing!
Couldn't agree more! I stumbled across his videos not too long ago and It's amazing how well he explain and describe everything they're working on. Love learning, moreover when it's explained by someone smart who loves what he does.
Brilliant presentation that is surely based on many many long hours of research , prototypes, production, modification and so on which obviously has been costly... Gracious of this channel to freely share all that has been accomplished. Bravo & Thank you.
18:20 - I like how you have applied boat building knowledge to the problem. This is why people that are conversant in many technologies can often find more innovative solutions.
Wow. Can we make this guy the model that all other educators use? The rate of information and the clarity of presentation, the brilliant logic used to dissect the science... its just ideal, I mean really the exact right way to explain any complex subject. If the lecturers on my physics degree (who were all blindingly clever as well) could do what this guy does, I swear the whole degree would have been 10% easier to get through.
Engineers are usually so quiet and don’t talk about their work unless you drag it out of them. This one of the very best channels on TH-cam. There should be at least a million more subs.
I have been trying to understand how airfoils work for 2 decades! Everything I have ever read or been taught has simply said 'the air has to travel further over the top, so it goes faster'. Which doesn't explain a thing! Why does it go faster, rather than just take longer? I did a bloody Physics degree, and that was the only answer I ever got. You have just explained it, clearly and succinctly in about 6 minutes. If I could, I would kiss you. Thank you so much.
I have been wanting to get into home made RC planes for years. And upon doing research for a pretty long time (no fancy degree for anything here), I almost just about wanted to buy a bunch of foam and trial and error my own wings. I started watching Tech Ingredients because of some of the jet videos as I really enjoyed the lecture process as much as the testing process. Just stumbled upon this video by accident and BOOM.. told me everything I needed to know to finish my rc fixed wing.
@@kalebgremmel1214 you might want to take a look at FliteTest too. They have a fleet of kits you can make with dollar-store foam board and hot glue. Their plans are all free, they post build videos on TH-cam, and they sell simple motor kits to drop into any of their planes. At the very least, you'll probably get some good techniques for gluing and folding your own designs.
I just stumbled across this content. So excellent! I'm build my wire cut foam wings skinned in fiberglass. Thanks for taking the time to produce this. Best!
amazing channel. i know its a pain to explain things you are familiar with but i learn so much watching you videos. i have a better understanding of everything from your in depth explanations. very grateful. but i’m still jealous of engineer scientist physicist and what you seem to just know
Yeah, but as a PhD in fluid mechanics, I find the explanation confusing/misleading. It’s true that Bernoulli CANNOT explain lift alone: Bernoulli is a simplification of the energy equation and you need the fully coupled conservation of mass (continuity), momentum (3 equations) and energy. But i find sixty symbols’ explanation more reasonable/accurate.
Very nice, looking forwards to seeing more. Using an existing blade to cast a mould is also a nice method, we used to do that for micro indoor models, they were a single layer but with a foam core a two skin propeller can be made in the same way.
We investigated that as well. The technique seemed reasonably straightforward.The challenge that discouraged us was that the foam needed to vary in thickness substantially because the airfoil thickness varies.substantially. Using these hot wire cut cores might simplify this. Also he negatives from the foam supplier might act as a mold if they were reinforced and coated with mold release. If you decide to pursue this, let us know and we would be happy to produce a video demonstration or to link to a video if you make one.
Man I love this channel - huge but definitely odd number of thumbs up on this video ! I love the thorough explanations ... I just hate it seeing people go like yeah nah it's just better that way - thanks for taking the time to make these video ! And kudos to everyone else involved in producing them - they look really nice - and that gimbal really adds coolness to each and every shot
Excellent -- background information is so important; will save lots of blind alley work; and your solution is very creative and demonstrates the time proven principle that your best tool is your brain. Thank you for all your hard work.
The meat and potatoes of a good introductory aerodynamics class explained clearly in about 12 minutes... well done!! (I could quibble about the flat plate L/D, but only if you want to:) Your presentation style is superbly smooth, clear, and holds attention. I'll recommend your channel to anyone wanting to firm up their understanding of the engineering behind their tinkering.
I thought I knew everything about foils and lift and drag and so on. So I watched this just for entertainment. Now - after watching - I know I failed while thinking to know everything. Thank you for the update! And for the entertainment too. :) Looking forward to next episode. Backdraw: I am so exited after watching every of your footages so I forget sometimes to klick the Thumb-Up. Sorry.
@@TechIngredients Oh! One thing I forgot to mention: Listen to your presentation is an excellent way to improve my english as I'm Kraut. Looks like you are a teacher in "real life". (I remember my Prof at Physics at Highscool - I loved him!)
This guy is great. His place reminds me of my ex’s parents house in northern Australia. He also reminds me of her father somewhat too. Anyway very interesting about the blades. Defo on to watch his next video.
How would you describe it? I recall lunch in a restaurant and we had arrived in the father’s car to have parked immediately opposite by ten feet. When we opened the door it was unbelievably hot. Those ten feet were almost too much to bare until reaching the air conditioned insides of the place. Where are you based, Canada at a wild guess?
Im really impressed that you can do this in one take. based off your ability to lecture nearly flawlessly my guess is you have to be a great professor. anyways, awesome video as always!
could you provide the website for Foam Flyers for their plans? I've been looking for it and can't seem to find it. BTW, thanks for the well done videos. Very informative.
I know Bernoulli, I understand Bernoulli, I can explain Bernoulli, I aced all tests involving Bernoulli, how the hell you manage to find an explanation that puts all my Physics professors to shame is beyond me. Awesome work.
The FAA should get you to update chapter 4 of the PHAK. The Coandă effect really helps explain what's going on where Bernoulli leaves off. I really like your lecture-style approach. I can only take so many "exciting" animations rehashing stuff I already know. I'm a grownup, gimme the facts and don't worry about dumbing it down too much.
Two questions, first, do you know of any readily available (and free) tools that can calculate the appropriate twist for a given set of parameters that will provide the correct angle of incidence to the relative airstream? My second question, is there an aerodynamic benefit to the bottom skin of the airfoil being hotter than the upper surface?
Excellent job sir. Explain aerodynamics is complex. Perhaps, it would be convenient to illustrate the four component forces by which sustainability occurs.
The cause-effect temporal superposition spin-spiral probability in/of mass-energy-momentum perceived as gas Thermodynamics goes deeper than the practical purposes approach, but requires a lot of terminology changes and reorientation of thought experiment guessing. Great teaching, I was looking forward to seeing a video on the topic.
saw an interesting video on copying the edge of a whale flipper onto a prop, and how it improved performance. In effect the forward edge has "wavy"like crenelations, rather than being a straight edge. The Increased efficiency comes when you incline for lift, and the low spots on the the edge are basically attacking with the same profile as an non-tilted edge, and the high spots are the only ones that suffer the drag of air that has to loop around the leading edge to get to the top,. So you halve the amount of the most resistant air flow
"Building the blades is not that difficult" you say. Dude your a genius. I just wanna see a drone fly out of this - Please the suspense is killing me .....
i thought the tapering has the same goal as changing angle of attack -- the linear speed of the tips is higher, but you need equal lift along the radius.
Marvelous! You did it again . Loved your explanation and no , is was not to technical, wha t You explained could not be made more simpele without losing necessary depth!
Awesome video... I've been researching making a propeller for a ultralight that I'm planning to make and the biggest hurdle that I have found is finding the appropriate prop I have found some that I like but they want ridiculous amounts of money.... way more than what you talked about. I need a prop that is about 42in. Looking to produce about 120 kg of thrust. At a max rpm of around 5500rpm. I believe that was the number I came up with to keep it from being super Sonic. I may need to go down in rpm alittle.
You might want to consider a slower propeller rotation. The thrust to power ratio of a propeller rises nearly linearly with diameter and falls nearly linearly with rotational speed. A propeller that is nearly supersonic at its tips is going to have areas of airflow over the surface that are even faster or trans-sonic. This is of course not accounting for the additional velocity added by forward flight.
Just dropping in to hit like button and toot toot comment. Why? Well, I think you guys do great work. Actually that is an unbelievably understated understatement.
Thank you for this channel. You are brilliant and have a gift for teaching and more than that making! Id love to see you on the lex Fridman podcast. Or joe rogan.
Looking at the thumbnail those are huge and going to be incredibly load ...I wounder if looking into how subs are quiet and maby moving it to them...I know it's diff medioms but might be worth thinking about
@@TechIngredients o cool thank you :)))...I love the vids helps me to understand all this in all feilds not just 1 like most that do ...like the phisics but no mechanics if that makes sence...you are the hole pizza pie in one well made video =^.^=
Awesome, thanks. Is wash-out on the tips not a necessary at all? Maybe rounding the tips would silence them a bit? Or does this affect the lift produced?
Rounding will probably not make a large difference. Extending and tipping the trailing edge can reduce the leakage of the higher velocity air on top, around to the bottom, inhibiting the creation of a tip vortex. This increases drag.
Hi! I have a quick question if anyone can answer, he mentions the lift of an aerofoil is mass*velocity, i.e. momentum, and energy is given by mass*velocity squared (i assume this refers to K.E. imparted to air i.e. KE = 0.5m*v^2). and hence the relationship between energy and lift is not linear. However, i was taught that lift=0.5*density*velocity^2 *wing area*Coeff of lift, and this shows that lift is propertional to velocity squared, can some please clarify this point for me? BTW, thank you so much for your content! I went to your oldest video and am currently working through it :).
What’s kind of payload do you get out of drones you have made with these? Designing a heavy lift drone right now for a startup and I’m shooting for anywhere from 15-25lb and if possible even more. Of course payload would depend on how much maneuverability I want as I reach the maximum.
Probably. Even though every airfoil will have an optimal AOA regarding effeciency, large rotors like on helicopters can't change their lift quickly due to inertia. So, pitch chang may be worth it on big drones to increase responsiveness.
I thought that wing's lift is coming from the fact that the air stream leaving the trailing edge has significant downward momentum. Air pressure and stuff are just forcing the air to follow the wing's curve.
If that was the reason then there would be little difference in the effeciency of an airfoil and a flat plate which also produces a downward airflow. Another piece of evidence to support my explanation is that the lift generated by airfoils centers around 30% back from the leading edge. This is why these wings don't experience a tremendous twisting force on their trailing edge.
First of all, wow, didn't expect you reading this, let alone replying. Second - thanks for all the videos - they are superb! Third: just googled that whole flight thing - serious can of worms that, apparently. Found this: www.aviation-history.com/theory/lift.htm Seems that "barn door" would be fine if not for stream detachment and stuff. By the way, your 30% argument is explained away (I think) by upwash. There are a lot of flamewars over this, I'm not here to start another one. It's just amusing that people are still arguing over this (flat-earthers notwithstanding). Thanks again! :)
I had some great teachers, but I guess they didn’t tinker enough in their professions and free time to convey basic and complex principles in an easy or practical application. Thanks
Tech Ingredients I’m 100% on board with that. We have the available technology and knowledge at our fingertips today to experiment and learn! Keep up the great work!
Excellent job explaining some of the design components of airfoils as they pertain to a propeller, but dude, you need to get a handle on that tansy in the yard...
No. That only applies when the entire rotor disk is moving rapidly through the air, perpendicular to plane of rotation, as with a propeller mounted on an airplane. Then, the relative wind passing over the airfoil varies as you move from the hub, where it is parallel to the flight direction, to become ever more parallel to the plane of the rotation as you move out toward the tip. This is why a helicopter rotor isn't twisted.
A few propellers and helicopter rotors do. The effect is to reduce the drag caused by the low pressure vortex which devlops as the lower velocity/higher pressure air below the airfoil flows over the tip to mix with the higher velocity/lower pressure air above. The tips reduce and displace this vortex away from the airfoil. The centrifugal forces on a rotor or propeller put a lot of load on that out of plane structure, so it tends to be smaller.
Hi, and thanks for your demonstration. I'm a former air traffic controller for the navy and an airman certificate holder for 20 years while I inspected just about every kind of aircraft in Southern Cal, Nevada, Arizona Texas and others. When an inspection needed doing, they called me. Because I always was there, on time, ready to go with the correct paper work and specifications, and I new what I was doing. My customers could tell, and had the utmost confidence in my abilities. Which brings me to this: Thanks a million. I would like to work together and draw from your knowledge. I'm in talks with a manufacturer to build the supporting structures and frame for the coolest looking and safest quatracopter ever built for the common traffic commuters that are currently being forced to terraform our planet, breath pollution for their daily 4 hour commutes to and from work, It's part of the new great "green deal." Most can't rap there heads around the enormous, yet simple challenge that will remove at least 3/4ths of the automobiles combustion engine and heavy pollution poisoning parts. Here in southern California, hundreds of thousand of cars and trucks commute into L,A, from all directions, with the average commute time being 4 a day. Usually their traveling at 5mph because of mass traffic jams do to too many cars and accidents. People are wasting there live in cars 4 hours a day yelling and screaming at the car next to them. What a fun way to live our lives. By the time they get home they're so angry, tired, and stressed which creates rapid health detiriation, which is accelerated by the breathing in and out the pollution from these cars for 4 hours a day, 5 to 6 days a week. That's a sad quality of life. My god, the tons of pollution these cars spew out into our planet every day. They are killing everything. They are actuallu terraforming our planet. With the improvement of the stabilizers in quatracopters, and the automation, Augmented reality and long lasting time of these new bio degradable batteries now used in cars like telsla, volt and fords leaf , we can now carry people, safely, through the air at 70-100mph, for 100 miles...1 hour at least per flight. We should get FREE batteries to R7D with from Detroit considering how many times you and I have bailed them out with out hard earned tax dollars. Anyhow, under project "the new green deal," we should get this passed and rolling quick. If we can get the cooperation needed, and will if they are serious about saving our planet for at least another 1000-2000 years, and avoid them worst war ever seen, which will occur in about 70 years when we start RUNNING OUT OF OIL. we can get 3/4 of these combustion engine planetary terraforming machines (automobiles) of the roads and replace with not MORE CARS THAT CAUSE MORE 4 HOURSE COMMUTES, but a flying quatracopter that looks so cool, like something Iron made, would build, and make look like the coolest ever, and get them flying. Besos from Amazon is trying, but he's doing it for ego and money and doesn't have a clue of the magnitude, yet simplicity of what it is going to take to get this new area of traffic under VFR's 500ft limit and above the obstructions that needs to be identified over all our freeways and roads so we know what the lower limits will be in certain areas, so our augmented visor can identify them in nice colors and warn us of the obstruction, show it to us, and advise us on the proper altitude adjustments needed to avoid, if we don't already know because of the maps on the visor that will be provided. (So Cool. So futuristic. So, I WANT THAT NOW!.)" At least that's what EVERYBODY will say when they see an operating model.) Beso has already tried with his ugly black and white bumble bee looking weird thing that no one would be caught seen dead in to get licensed with the FHA. They giggled a little and gave a him an ultralight designation. "Nope, can't fly over freeways or roads or approved short cuts. You need a lot of R&D." All those billions of dollars and he couldn't even get it right. Because HE has to do it all because HE is the genius, He put "yellow pages" on line, and sold books. He obviously isn't a genius, or he would have got this right the first time, and then some. It isn't like he didn't have all the money in the world to do it right. But he wanted to do it all his self, because he's the genius…..NOT! Once you have all that information gathered and together, including all the safety features, and shown all the possible things that can go wrong, including lightning strikes, and every cash, and results imaginable, they won't even give you a second look. You have to have all your crap together, including safety procedures, training requirements to fly, just like you do to drive a car or fly a Cessna. Insurance companies have to agree to insure, which means you have to show the worst crash causes the same, or less damage as a truck would crashing on a freeway. Which will be easy, because the VCM (vertical commute vehicle) only weighs 400-500lbs max. Without all the combustion engine parts, the cost will be so low, and with government financing and help (not to mention saving the planet, which constitutes national security, right?) these VCM's shouldn't coast more than $25k basic 1 seater to the $45k model with all the bells and whistles 5 seater.This makes it within the reach of the masses. I know its a lot to take on. But if you can make the propellers, and NOT GOUGE US (yourself) for price, coordinating and building the quatracopter propellers can be yours, if you want to be part of something that will be done soon. If not by us, then by someone else. 2 kids over sea's are already making some good strides. But once again-greed, money and ego is ruining their chance at history. Imagine how many cars in the would, and lets say you get 1/2. That's a pretty penny, and you are saving the world and improving our quality of life for us by 10 fold. What do you think? I'm in talks with the Green Project people and my congressperson. My governor is pretending he's not getting my information because he just made a worthless auto emissions deal with Detroit, that goes away as soon as he's not governor anymore. We all know how that works. He thinks it will help with votes in his future presidential run. That SHOWS ME he's too stupid to be president. Because republicans and democrats alike will embrace whatever figure head makes this happen, and brings this planet saving, health improving, baby saving, war preventing idea. I've already created 10 new freeway lanes on the 101 freeway and 405 freeway in SoCal for how much money? ZeRO. I created ten new lanes of traffic and it didn't cost a dime. Our governor is wasting 2 billion dollars on a choo choo train that STILL doesn't get you inside the airport. Just another drop off. And sure does make it a lot easier for a crazy to take out a lot of people in one pop now that they are all in one place. Not to mention the poor drivers that drive for a living.They should have more openminded thinkers like us on the job. Maybe they might actually get something worth doing, DONE! thank Roger 818-2979394 if interested.
Hey! I’m loving these videos!! How do I send you a PDF document. I ordered some info on DIY props that’s I’d like to share!!! Perhaps you can build and test, I’d love to see your results!!!
I have a question You are trying to run an APU to generate electricity to run multiple electric motors. Would it not be more efficient for your motor to drive all the blades simultaneously and then to have separate pitch control on each blade, like a helicopter collective. You would come back to the control and systems of modern drones but have the power and range of little gas engines. You could then use model helicopter blades, assuming you could find counter rotating pairs. Props could be clocked to eliminate their imbalances
It would be more efficient, but your later points are very important. It may just not be practical to redesign the entire system from energy source all the way through to the rotors for that gain in efficiency.
Would it be worthwhile to experiment with a curved leading edge ie a scimitar propeller as is seen on the AC-130 Hercules ? Also, would a drone that can change its propellor orientation like the Osprey be feasible ? I’m guessing added weight of the tilting mechanism could negate any performance gains. Thanks again for another very informative video ! 👍
9:15 “The lift of an airfoil is the mass times velocity and the drag of an airfoil is the mass times the velocity squared”. Am I missing something here or is this just blatantly wrong? Last time I checked the lift force and the drag force were both functions of dynamic pressure (density times velocity squared).
Very nice - but how do you make sure that the propeller can handle the appropriate load. For example if you have a DLE 222 with a thrust of 50kg, I can hardly believe that such a prop as shown can handle the load. Just imagine those joints of the blade have a load of 25kg each.
Thanks! Firstly, why choose 50kg? To estimate the maximum load, apply the load to the midpoint of the blade when the hub is clamped and increase until failure.. repeat to confirm.
@@TechIngredients Sorry - may be jumping just too far. Lets say you have a quad copter with a MTOW of 200kg (purposely using large numbers). So each motor would lift 50kg and each propeller would need to lift 50kg. So if I look closely how each prop is attached to the el. motor axle, I wonder if this construction can handle this load. The 34 props available are all solid at the prop axle hole and in most cases you have 6 screws to attach it to the prop hub. Your proposed construction and the load such a blade can handle - I would guess is great. But again the weak point, I think, is where the blade is attached. Don't get me wrong - you make great clips and show an amazing amount of details. Currently I am considering myself to build a 34 inch prop which should lift 50kg. But my calc tells me it needs a solid wood core - not balsa - to be able to handle such a load (carbon fiber lamination for extra strength).
There is no substitute for testing. This can be used along with the design process rather than limited to a final test of the completed build. Destructive testing is also useful despite the apparent cost because you'll learn the failure mechanism and surprises can prevent more costly damage downstream.
That is correct, but remember that lift is the result of momentum transfer from the airfoil to the air. As the airfoil's velocity increases through the air, the mass it interacts with increases and the velocity that it induces in that increased mass increases as well. The resulting drag increases as the square of the velocity and the energy expended rises to the third power of the velocity.
Tech Ingredients You are taking a leap into more complicated aerodynamics I am able to handle but still the formulas of lift and drag are clear and undisputed as far as I know.
You are correct and I am not disputing this. The point I am making is based on what we agree is true and that is; the ENERGY used is to a higher power. As movement through the air speeds up the amount of air interacted with increases and the velocity resulting from that interaction increases. Drag and lift are proportional to the mass of the air moved times the velocity that it is accelerated to. The energy used is proportional to the mass of the air moved times the square of the velocity it is accelerated to. For both aspects of flight, propulsion and lift, slower is more energy effecient.
No, we didn't. Blade twist is incorporated in typical propellers because the forward motion through the air causes the "relative wind" to strike the airfoil forward of the plane of rotation. This maintains the optimal angle of attack as an airplane or a very fast drone flies through the air. Slow moving, "heavy lift" drones, as well as many slower, high capacity helicopters do not have twist. Even the very expensive T-Motor propeller we demonstrated is not designed correctly as the inner diameter of the propeller is operating at such a high angle of attack that it is in a stall condition.
"Thank you for your patience" This kind of in-depth explanation is just the cause I like to visit this channel. Excellent content, thank you sir!
Sure!
This channel takes DIY to the absolute edge of achievment in a home shop environment. We need more in depth projects like this. Even if I don't build these projects, I learn so much that I can't stop watching.
This is an excellent channel, thanks for sharing so much amazing info!
the way he explains this actually make's my third eye see this as if i was looking at a illustration in a text book 'amazing'
You're a great teacher! I've never had such a complete understanding of airfoils.
This is fantastic and sad at the same time. I have rarely heard anybody explain things in such a clear, comprehensive and thorough way like he is. This is premium quality information for sure....and it has 203 likes. This should be reposted with a clickbait title like: how wings actually lift...finally REVEALED. Thank you.
You're welcome. Despite what many believe, physics is not hard, none of it. It's the maths that put people off and that's a shame. Take a look at our other videos even if you are not interested in lasers, I'll bet you come away with much the same impression. Our channel is literally exploding and many of these videos will be soon be seen by a much wider audience.
Funny you say that I am an Aero Engineer and I worked in Propellers 30 years ago , I haven't heard such an educated explanation except by a few of the old prop engineers, my college professors had no clue. This guy is good!
Best explanation of lift I've ever heard. I've been trying to reset my understanding since I learned Bernoulli's can't explain it fully, but was unable to find a good explanation. Thanks!
wow. just wow! looking at a propeler blande and finally understanding exactly why things are the way they are. Every piece of geometry on it has a reason. Nothing is random. And now seeing how i can even build it. That's mind blowing!
That was the point, great!
You sir, are astounding. Great video, and I'm glad I came across your channel.
DrewB 213
Couldn’t agree more.
Most people with this mans knowledge and skills do not wish to share it and/or lack the ability to convey it.
Couldn't agree more! I stumbled across his videos not too long ago and It's amazing how well he explain and describe everything they're working on. Love learning, moreover when it's explained by someone smart who loves what he does.
I found this guy less 20hrs ago and binged the whole channel in chronological order; am so inspired to hit my workbench!!
And outstanding - I can’t recommend this channel more highly.
Brilliant presentation that is surely based on many many long hours of research , prototypes, production, modification and so on which obviously has been costly... Gracious of this channel to freely share all that has been accomplished. Bravo & Thank you.
You're welcome!
Just brilliant. Love your description of how an aerofoil/prop/wing works best I've ever heard thanks so much
18:20 - I like how you have applied boat building knowledge to the problem. This is why people that are conversant in many technologies can often find more innovative solutions.
Wow. Can we make this guy the model that all other educators use? The rate of information and the clarity of presentation, the brilliant logic used to dissect the science... its just ideal, I mean really the exact right way to explain any complex subject. If the lecturers on my physics degree (who were all blindingly clever as well) could do what this guy does, I swear the whole degree would have been 10% easier to get through.
You are truly amazing. The depth of knowledge about such a wide variety of topics is just so cool.
Nice thermodynamic explanation of the Bernoulli effect. I finally understand the why of it, which has been bugging me for 30 years!
You explained it well. Thanks for the clarity and the multiple examples. Can't wait to see the testing!
This is amazing, I've been reading textbooks for weeks and didn't learn as much practical stuff
Thank you!
Engineers are usually so quiet and don’t talk about their work unless you drag it out of them. This one of the very best channels on TH-cam. There should be at least a million more subs.
Thanks!
Give us a little more time...
Your incredibly generous gift of knowledge is greatly appreciated. Thank you.
Great video it is so nice to have found someone that can prove why something works or doesn’t work
You can feel how you get smarter by watching these videos! Thank you sir, you are astounding!
Thanks for spending the time to watch and to comment!
I have been trying to understand how airfoils work for 2 decades! Everything I have ever read or been taught has simply said 'the air has to travel further over the top, so it goes faster'. Which doesn't explain a thing! Why does it go faster, rather than just take longer? I did a bloody Physics degree, and that was the only answer I ever got. You have just explained it, clearly and succinctly in about 6 minutes. If I could, I would kiss you. Thank you so much.
Thank you!
I have been wanting to get into home made RC planes for years. And upon doing research for a pretty long time (no fancy degree for anything here), I almost just about wanted to buy a bunch of foam and trial and error my own wings. I started watching Tech Ingredients because of some of the jet videos as I really enjoyed the lecture process as much as the testing process. Just stumbled upon this video by accident and BOOM.. told me everything I needed to know to finish my rc fixed wing.
@@kalebgremmel1214 you might want to take a look at FliteTest too. They have a fleet of kits you can make with dollar-store foam board and hot glue. Their plans are all free, they post build videos on TH-cam, and they sell simple motor kits to drop into any of their planes. At the very least, you'll probably get some good techniques for gluing and folding your own designs.
Same here…
I'm most greatful to you for producing this video. It was very helpful and easy to understand.
- Thomas from Australia. 🇦🇺
Thanks!
I just stumbled across this content. So excellent! I'm build my wire cut foam wings skinned in fiberglass. Thanks for taking the time to produce this. Best!
amazing channel. i know its a pain to explain things you are familiar with but i learn so much watching you videos. i have a better understanding of everything from your in depth explanations. very grateful. but i’m still jealous of engineer scientist physicist and what you seem to just know
Amazing... Who IS this guy?? Where was he when I was studying engineering?
Dr. Eric T Meyer
Yeah, but as a PhD in fluid mechanics, I find the explanation confusing/misleading. It’s true that Bernoulli CANNOT explain lift alone: Bernoulli is a simplification of the energy equation and you need the fully coupled conservation of mass (continuity), momentum (3 equations) and energy. But i find sixty symbols’ explanation more reasonable/accurate.
Wonderful work ! Thank you, and looking forward to viewing your followup videos.
Very nice, looking forwards to seeing more. Using an existing blade to cast a mould is also a nice method, we used to do that for micro indoor models, they were a single layer but with a foam core a two skin propeller can be made in the same way.
We investigated that as well. The technique seemed reasonably straightforward.The challenge that discouraged us was that the foam needed to vary in thickness substantially because the airfoil thickness varies.substantially. Using these hot wire cut cores might simplify this. Also he negatives from the foam supplier might act as a mold if they were reinforced and coated with mold release.
If you decide to pursue this, let us know and we would be happy to produce a video demonstration or to link to a video if you make one.
Man I love this channel - huge but definitely odd number of thumbs up on this video !
I love the thorough explanations ... I just hate it seeing people go like yeah nah it's just better that way - thanks for taking the time to make these video ! And kudos to everyone else involved in producing them - they look really nice - and that gimbal really adds coolness to each and every shot
Excellent -- background information is so important; will save lots of blind alley work; and your solution is very creative and demonstrates the time proven principle that your best tool is your brain. Thank you for all your hard work.
Thanks!
Fascinating! Thanks for the effort you put in to this!
The meat and potatoes of a good introductory aerodynamics class explained clearly in about 12 minutes... well done!! (I could quibble about the flat plate L/D, but only if you want to:) Your presentation style is superbly smooth, clear, and holds attention. I'll recommend your channel to anyone wanting to firm up their understanding of the engineering behind their tinkering.
Thanks, that helps a lot.
I like the fact that you DON'T try to simplify yourself, so that everyone can understand. We need tedious to fully understand. Don't apologize.
It was precise and to the point!! Thanks for that remarkable and insightful explanation
Thanks!
Great video! It would be great if you added links to your foam core supplier. Foam Flyers gets too many hits to sort out. Thanks!
you are an absolutely incredible teacher!
Thanks!
I thought I knew everything about foils and lift and drag and so on.
So I watched this just for entertainment.
Now - after watching - I know I failed while thinking to know everything. Thank you for the update! And for the entertainment too. :)
Looking forward to next episode.
Backdraw: I am so exited after watching every of your footages so I forget sometimes to klick the Thumb-Up. Sorry.
Thanks!
All is forgiven. 😀
@@TechIngredients Oh! One thing I forgot to mention: Listen to your presentation is an excellent way to improve my english as I'm Kraut.
Looks like you are a teacher in "real life". (I remember my Prof at Physics at Highscool - I loved him!)
Explained better and more knowledgeable than a professor!!!!!
yeah.. you made the best explanation of the theory behind laminar flow.
Thank you Sir!
This is the best channel on TH-cam by far.
Thanks!
This guy is great. His place reminds me of my ex’s parents house in northern Australia. He also reminds me of her father somewhat too. Anyway very interesting about the blades. Defo on to watch his next video.
Been to Darwin, have to say I didn't like the weather, no not at all.
How would you describe it? I recall lunch in a restaurant and we had arrived in the father’s car to have parked immediately opposite by ten feet. When we opened the door it was unbelievably hot. Those ten feet were almost too much to bare until reaching the air conditioned insides of the place. Where are you based, Canada at a wild guess?
great work.
This explanation of airfoil is the best scientific out there
Love your channel. I wish I'd had a father or mentor of some sort like you.
And it is very inspiring when someone like you expresses such a desire... I would love to have a daugther or student like you!!!
Is there a formula for number of things learned per second on a TH-cam channel vs number of times I don't understand? This channel is top rated :-)
Thanks!
You explained why the wind moves through buildings like a wave of water. Thanx
Im really impressed that you can do this in one take. based off your ability to lecture nearly flawlessly my guess is you have to be a great professor. anyways, awesome video as always!
Thanks!
could you provide the website for Foam Flyers for their plans? I've been looking for it and can't seem to find it. BTW, thanks for the well done videos. Very informative.
Thank you.
Sorry to say, but they went out of business a couple of years ago.
@@TechIngredients you indicated that there were others. Suggestions?
Spectacular information.
That is a great badass picture on the cover of the video :3
You explain this better than any of my flight school instructors ever did...
Thanks!
I know Bernoulli, I understand Bernoulli, I can explain Bernoulli, I aced all tests involving Bernoulli, how the hell you manage to find an explanation that puts all my Physics professors to shame is beyond me. Awesome work.
They probably didn't appreciate what Bernoulli understood. Never rely on equations to substitute for an understanding of the principles.
Well spoken sir! THANK YOU for uploading this.
This channel is a rare find... subscribed after this video.
Thanks a lot!
The FAA should get you to update chapter 4 of the PHAK. The Coandă effect really helps explain what's going on where Bernoulli leaves off.
I really like your lecture-style approach. I can only take so many "exciting" animations rehashing stuff I already know. I'm a grownup, gimme the facts and don't worry about dumbing it down too much.
Just loved watching this tutorial video.
It's quite useful to me.
Great!
Two questions, first, do you know of any readily available (and free) tools that can calculate the appropriate twist for a given set of parameters that will provide the correct angle of incidence to the relative airstream? My second question, is there an aerodynamic benefit to the bottom skin of the airfoil being hotter than the upper surface?
Sorry, I can't answer either question, but I suspect the effect of heating the lower surface of the airfoil will be negligible.
Very good explination. Thank You.
tapering the wing produces weaker vortices - makes the wing more efficient. so does adding fences to the tips (bottom only)
That's true as well.
Amazing video! So dense in useful information... Thanks a lot!
You're welcome.
Excellent job sir. Explain aerodynamics is complex. Perhaps, it would be convenient to illustrate the four component forces by which sustainability occurs.
This guy sucked me into another 1/2hr lecture! lol Love to learn though. Great teaching skills.
The cause-effect temporal superposition spin-spiral probability in/of mass-energy-momentum perceived as gas Thermodynamics goes deeper than the practical purposes approach, but requires a lot of terminology changes and reorientation of thought experiment guessing.
Great teaching, I was looking forward to seeing a video on the topic.
saw an interesting video on copying the edge of a whale flipper onto a prop, and how it improved performance. In effect the forward edge has "wavy"like crenelations, rather than being a straight edge. The Increased efficiency comes when you incline for lift, and the low spots on the the edge are basically attacking with the same profile as an non-tilted edge, and the high spots are the only ones that suffer the drag of air that has to loop around the leading edge to get to the top,. So you halve the amount of the most resistant air flow
Interesting.
Great! You're addressing a real issue! Thanks..)
"Building the blades is not that difficult" you say. Dude your a genius. I just wanna see a drone fly out of this - Please the suspense is killing me .....
Right. Declares that it's easy. Details the 49 steps required.
Great job as usual.
i thought the tapering has the same goal as changing angle of attack -- the linear speed of the tips is higher, but you need equal lift along the radius.
Links to core supplier and supplies???
Marvelous! You did it again .
Loved your explanation and no , is was not to technical, wha t You explained could not be made more simpele without losing necessary depth!
Thanks!
Awesome video... I've been researching making a propeller for a ultralight that I'm planning to make and the biggest hurdle that I have found is finding the appropriate prop I have found some that I like but they want ridiculous amounts of money.... way more than what you talked about. I need a prop that is about 42in. Looking to produce about 120 kg of thrust. At a max rpm of around 5500rpm. I believe that was the number I came up with to keep it from being super Sonic. I may need to go down in rpm alittle.
You might want to consider a slower propeller rotation. The thrust to power ratio of a propeller rises nearly linearly with diameter and falls nearly linearly with rotational speed. A propeller that is nearly supersonic at its tips is going to have areas of airflow over the surface that are even faster or trans-sonic. This is of course not accounting for the additional velocity added by forward flight.
Just dropping in to hit like button and toot toot comment.
Why? Well, I think you guys do great work. Actually that is an unbelievably understated understatement.
Great video! Thank you
Thank you for this channel. You are brilliant and have a gift for teaching and more than that making! Id love to see you on the lex Fridman podcast. Or joe rogan.
Looking at the thumbnail those are huge and going to be incredibly load ...I wounder if looking into how subs are quiet and maby moving it to them...I know it's diff medioms but might be worth thinking about
Actually, the larger they are the quieter they are. Noise is strongly correlated with air velocity.
@@TechIngredients o cool thank you :)))...I love the vids helps me to understand all this in all feilds not just 1 like most that do ...like the phisics but no mechanics if that makes sence...you are the hole pizza pie in one well made video =^.^=
Awesome, thanks. Is wash-out on the tips not a necessary at all? Maybe rounding the tips would silence them a bit? Or does this affect the lift produced?
Rounding will probably not make a large difference. Extending and tipping the trailing edge can reduce the leakage of the higher velocity air on top, around to the bottom, inhibiting the creation of a tip vortex. This increases drag.
Tedious? Fascinating!
Absolutely brilliant!
Great explaination.
Hi! I have a quick question if anyone can answer, he mentions the lift of an aerofoil is mass*velocity, i.e. momentum, and energy is given by mass*velocity squared (i assume this refers to K.E. imparted to air i.e. KE = 0.5m*v^2). and hence the relationship between energy and lift is not linear. However, i was taught that lift=0.5*density*velocity^2 *wing area*Coeff of lift, and this shows that lift is propertional to velocity squared, can some please clarify this point for me?
BTW, thank you so much for your content! I went to your oldest video and am currently working through it :).
Sure. Notice that the second equation does not factor in the change in mass flow.
@@TechIngredients I see, thank you very much. I really appreciate all the content you put out and the depth of your understanding is astounding.
What’s kind of payload do you get out of drones you have made with these? Designing a heavy lift drone right now for a startup and I’m shooting for anywhere from 15-25lb and if possible even more. Of course payload would depend on how much maneuverability I want as I reach the maximum.
Could a large multi rotor benefit from a collective pitch control mixed with traditional motor speed control?
Probably. Even though every airfoil will have an optimal AOA regarding effeciency, large rotors like on helicopters can't change their lift quickly due to inertia. So, pitch chang may be worth it on big drones to increase responsiveness.
Thanks for responding :) it has definitely helped fuel my imagination ;)
The audio visual quality has improved significantly since this episode.
Thanks!
I thought that wing's lift is coming from the fact that the air stream leaving the trailing edge has significant downward momentum. Air pressure and stuff are just forcing the air to follow the wing's curve.
If that was the reason then there would be little difference in the effeciency of an airfoil and a flat plate which also produces a downward airflow. Another piece of evidence to support my explanation is that the lift generated by airfoils centers around 30% back from the leading edge. This is why these wings don't experience a tremendous twisting force on their trailing edge.
First of all, wow, didn't expect you reading this, let alone replying. Second - thanks for all the videos - they are superb! Third: just googled that whole flight thing - serious can of worms that, apparently. Found this: www.aviation-history.com/theory/lift.htm Seems that "barn door" would be fine if not for stream detachment and stuff. By the way, your 30% argument is explained away (I think) by upwash. There are a lot of flamewars over this, I'm not here to start another one. It's just amusing that people are still arguing over this (flat-earthers notwithstanding). Thanks again! :)
I had some great teachers, but I guess they didn’t tinker enough in their professions and free time to convey basic and complex principles in an easy or practical application. Thanks
This is why I don't like the current educational system and prefer apprenticeship. It has a much longer legacy for good reason.
Tech Ingredients I’m 100% on board with that. We have the available technology and knowledge at our fingertips today to experiment and learn! Keep up the great work!
Excellent job explaining some of the design components of airfoils as they pertain to a propeller, but dude, you need to get a handle on that tansy in the yard...
Isn't the angle of attack supposed to vary along the length of the blade?
No. That only applies when the entire rotor disk is moving rapidly through the air, perpendicular to plane of rotation, as with a propeller mounted on an airplane. Then, the relative wind passing over the airfoil varies as you move from the hub, where it is parallel to the flight direction, to become ever more parallel to the plane of the rotation as you move out toward the tip. This is why a helicopter rotor isn't twisted.
@@TechIngredients got it! Thank you
very, very nice and good.
Why do wing blades have the curved up tips for efficiency but propellers do not?
A few propellers and helicopter rotors do. The effect is to reduce the drag caused by the low pressure vortex which devlops as the lower velocity/higher pressure air below the airfoil flows over the tip to mix with the higher velocity/lower pressure air above. The tips reduce and displace this vortex away from the airfoil. The centrifugal forces on a rotor or propeller put a lot of load on that out of plane structure, so it tends to be smaller.
Hi, and thanks for your demonstration. I'm a former air traffic controller for the navy and an airman certificate holder for 20 years while I inspected just about every kind of aircraft in Southern Cal, Nevada, Arizona Texas and others. When an inspection needed doing, they called me. Because I always was there, on time, ready to go with the correct paper work and specifications, and I new what I was doing. My customers could tell, and had the utmost confidence in my abilities. Which brings me to this: Thanks a million. I would like to work together and draw from your knowledge. I'm in talks with a manufacturer to build the supporting structures and frame for the coolest looking and safest quatracopter ever built for the common traffic commuters that are currently being forced to terraform our planet, breath pollution for their daily 4 hour commutes to and from work, It's part of the new great "green deal." Most can't rap there heads around the enormous, yet simple challenge that will remove at least 3/4ths of the automobiles combustion engine and heavy pollution poisoning parts. Here in southern California, hundreds of thousand of cars and trucks commute into L,A, from all directions, with the average commute time being 4 a day. Usually their traveling at 5mph because of mass traffic jams do to too many cars and accidents. People are wasting there live in cars 4 hours a day yelling and screaming at the car next to them. What a fun way to live our lives. By the time they get home they're so angry, tired, and stressed which creates rapid health detiriation, which is accelerated by the breathing in and out the pollution from these cars for 4 hours a day, 5 to 6 days a week. That's a sad quality of life. My god, the tons of pollution these cars spew out into our planet every day. They are killing everything. They are actuallu terraforming our planet. With the improvement of the stabilizers in quatracopters, and the automation, Augmented reality and long lasting time of these new bio degradable batteries now used in cars like telsla, volt and fords leaf , we can now carry people, safely, through the air at 70-100mph, for 100 miles...1 hour at least per flight. We should get FREE batteries to R7D with from Detroit considering how many times you and I have bailed them out with out hard earned tax dollars. Anyhow, under project "the new green deal," we should get this passed and rolling quick. If we can get the cooperation needed, and will if they are serious about saving our planet for at least another 1000-2000 years, and avoid them worst war ever seen, which will occur in about 70 years when we start RUNNING OUT OF OIL. we can get 3/4 of these combustion engine planetary terraforming machines (automobiles) of the roads and replace with not MORE CARS THAT CAUSE MORE 4 HOURSE COMMUTES, but a flying quatracopter that looks so cool, like something Iron made, would build, and make look like the coolest ever, and get them flying. Besos from Amazon is trying, but he's doing it for ego and money and doesn't have a clue of the magnitude, yet simplicity of what it is going to take to get this new area of traffic under VFR's 500ft limit and above the obstructions that needs to be identified over all our freeways and roads so we know what the lower limits will be in certain areas, so our augmented visor can identify them in nice colors and warn us of the obstruction, show it to us, and advise us on the proper altitude adjustments needed to avoid, if we don't already know because of the maps on the visor that will be provided. (So Cool. So futuristic. So, I WANT THAT NOW!.)" At least that's what EVERYBODY will say when they see an operating model.) Beso has already tried with his ugly black and white bumble bee looking weird thing that no one would be caught seen dead in to get licensed with the FHA. They giggled a little and gave a him an ultralight designation. "Nope, can't fly over freeways or roads or approved short cuts. You need a lot of R&D." All those billions of dollars and he couldn't even get it right. Because HE has to do it all because HE is the genius, He put "yellow pages" on line, and sold books. He obviously isn't a genius, or he would have got this right the first time, and then some. It isn't like he didn't have all the money in the world to do it right. But he wanted to do it all his self, because he's the genius…..NOT! Once you have all that information gathered and together, including all the safety features, and shown all the possible things that can go wrong, including lightning strikes, and every cash, and results imaginable, they won't even give you a second look. You have to have all your crap together, including safety procedures, training requirements to fly, just like you do to drive a car or fly a Cessna. Insurance companies have to agree to insure, which means you have to show the worst crash causes the same, or less damage as a truck would crashing on a freeway. Which will be easy, because the VCM (vertical commute vehicle) only weighs 400-500lbs max. Without all the combustion engine parts, the cost will be so low, and with government financing and help (not to mention saving the planet, which constitutes national security, right?) these VCM's shouldn't coast more than $25k basic 1 seater to the $45k model with all the bells and whistles 5 seater.This makes it within the reach of the masses. I know its a lot to take on. But if you can make the propellers, and NOT GOUGE US (yourself) for price, coordinating and building the quatracopter propellers can be yours, if you want to be part of something that will be done soon. If not by us, then by someone else. 2 kids over sea's are already making some good strides. But once again-greed, money and ego is ruining their chance at history. Imagine how many cars in the would, and lets say you get 1/2. That's a pretty penny, and you are saving the world and improving our quality of life for us by 10 fold. What do you think? I'm in talks with the Green Project people and my congressperson. My governor is pretending he's not getting my information because he just made a worthless auto emissions deal with Detroit, that goes away as soon as he's not governor anymore. We all know how that works. He thinks it will help with votes in his future presidential run. That SHOWS ME he's too stupid to be president. Because republicans and democrats alike will embrace whatever figure head makes this happen, and brings this planet saving, health improving, baby saving, war preventing idea. I've already created 10 new freeway lanes on the 101 freeway and 405 freeway in SoCal for how much money? ZeRO. I created ten new lanes of traffic and it didn't cost a dime. Our governor is wasting 2 billion dollars on a choo choo train that STILL doesn't get you inside the airport. Just another drop off. And sure does make it a lot easier for a crazy to take out a lot of people in one pop now that they are all in one place. Not to mention the poor drivers that drive for a living.They should have more openminded thinkers like us on the job. Maybe they might actually get something worth doing, DONE! thank Roger 818-2979394 if interested.
Have you ever looked at paramotor propellers? I get 115 to 160 cm carbon fiber props for around $400.
Yes, they are an attractive option.
Hey! I’m loving these videos!! How do I send you a PDF document. I ordered some info on DIY props that’s I’d like to share!!! Perhaps you can build and test, I’d love to see your results!!!
I have a question
You are trying to run an APU to generate electricity to run multiple electric motors.
Would it not be more efficient for your motor to drive all the blades simultaneously and then to have separate pitch control on each blade, like a helicopter collective.
You would come back to the control and systems of modern drones but have the power and range of little gas engines.
You could then use model helicopter blades, assuming you could find counter rotating pairs.
Props could be clocked to eliminate their imbalances
It would be more efficient, but your later points are very important. It may just not be practical to redesign the entire system from energy source all the way through to the rotors for that gain in efficiency.
Would it be worthwhile to experiment with a curved leading edge ie a scimitar propeller as is seen on the AC-130 Hercules ?
Also, would a drone that can change its propellor orientation like the Osprey be feasible ? I’m guessing added weight of the tilting mechanism could negate any performance gains.
Thanks again for another very informative video ! 👍
Probably not as the drones these would be mounted on travel relatively slowly.
This is excellent
9:15 “The lift of an airfoil is the mass times velocity and the drag of an airfoil is the mass times the velocity squared”. Am I missing something here or is this just blatantly wrong? Last time I checked the lift force and the drag force were both functions of dynamic pressure (density times velocity squared).
Ah, ok rotor theory vs wings... I guess explanations for the lay-person of fluid dynamics is challenging-probably done here much better than I could.
I’m
Just salty because his tools & workshop is much better than mine (I don’t have one 🤣😭)
Very nice - but how do you make sure that the propeller can handle the appropriate load. For example if you have a DLE 222 with a thrust of 50kg, I can hardly believe that such a prop as shown can handle the load. Just imagine those joints of the blade have a load of 25kg each.
Thanks!
Firstly, why choose 50kg?
To estimate the maximum load, apply the load to the midpoint of the blade when the hub is clamped and increase until failure.. repeat to confirm.
@@TechIngredients Sorry - may be jumping just too far. Lets say you have a quad copter with a MTOW of 200kg (purposely using large numbers). So each motor would lift 50kg and each propeller would need to lift 50kg. So if I look closely how each prop is attached to the el. motor axle, I wonder if this construction can handle this load. The 34 props available are all solid at the prop axle hole and in most cases you have 6 screws to attach it to the prop hub. Your proposed construction and the load such a blade can handle - I would guess is great. But again the weak point, I think, is where the blade is attached.
Don't get me wrong - you make great clips and show an amazing amount of details. Currently I am considering myself to build a 34 inch prop which should lift 50kg. But my calc tells me it needs a solid wood core - not balsa - to be able to handle such a load (carbon fiber lamination for extra strength).
There is no substitute for testing. This can be used along with the design process rather than limited to a final test of the completed build. Destructive testing is also useful despite the apparent cost because you'll learn the failure mechanism and surprises can prevent more costly damage downstream.
Velocity squared is in the formula of both lift and drag
That is correct, but remember that lift is the result of momentum transfer from the airfoil to the air. As the airfoil's velocity increases through the air, the mass it interacts with increases and the velocity that it induces in that increased mass increases as well. The resulting drag increases as the square of the velocity and the energy expended rises to the third power of the velocity.
Tech Ingredients You are taking a leap into more complicated aerodynamics I am able to handle but still the formulas of lift and drag are clear and undisputed as far as I know.
You are correct and I am not disputing this. The point I am making is based on what we agree is true and that is; the ENERGY used is to a higher power. As movement through the air speeds up the amount of air interacted with increases and the velocity resulting from that interaction increases. Drag and lift are proportional to the mass of the air moved times the velocity that it is accelerated to. The energy used is proportional to the mass of the air moved times the square of the velocity it is accelerated to. For both aspects of flight, propulsion and lift, slower is more energy effecient.
can this be easily used for a car drone because the vibration problem might not matter.
You forgot about twisting the blade to create a higher angle of attack near the hub.
No, we didn't. Blade twist is incorporated in typical propellers because the forward motion through the air causes the "relative wind" to strike the airfoil forward of the plane of rotation. This maintains the optimal angle of attack as an airplane or a very fast drone flies through the air. Slow moving, "heavy lift" drones, as well as many slower, high capacity helicopters do not have twist. Even the very expensive T-Motor propeller we demonstrated is not designed correctly as the inner diameter of the propeller is operating at such a high angle of attack that it is in a stall condition.