Use code RCTESTFLIGHT50 to get 50% off your first Factor box at bit.ly/3RfkGTR!

@Milkmans_Son

10 ай бұрын

I have a question about this video. Why in the hell would a product or brand not want the free exposure you gave them in the earlier video? I don't get it.

@Starfleetfly

10 ай бұрын

When are you going to make a solar catamaran?

@NastyWicked

10 ай бұрын

And fuck tupperware

@JacksonSubNScaleModelRailroad

10 ай бұрын

Is there a such thing as negative ground effect? Like ceiling effect? I have noticed that when I fly smaller quadcopters and get too close to the ceiling, they tend to suck themselves up into the ceiling, usually sending ceiling popcorn all over the place!!!

@Fortenurg

10 ай бұрын

Please make a video with your large props and silent motors, you could really be on to something in the silent drone world.

The t Company Should sponser you instead of Sending Their lawers

@HoneyDoll894

10 ай бұрын

its a multilevel marketing product so probably shouldn't give it advertisement

@kylek29

10 ай бұрын

It also might be to prevent losing the trademark. The more a brand name is used to describe a type of product, the higher chance it can be ruled as part of the common lexicon, stripping the trademark protection. This is what happened to Kleenex and a few other brands. It's also why Google was cracking down on "just Google it" because they didn't want to lose the TM if Google became synonymous with "searching online."

@eelcoyle3373

10 ай бұрын

Just boycott em , same for any company; bad-practice=boycott 🤙

@alxgu198

10 ай бұрын

You can say it, tupperware (deliberately without a capital 😉).

@nathantoews152

10 ай бұрын

I think the problem the company had is that none of those boxes are Tupperware. Bad for their brand equating an different product.

You were sooo close to re-discovering hovercrafts with that large skirt :D

Loving these projects and where they do or dont lead.

@peterpizzurro9410

10 ай бұрын

A fail teaches you something.

@wbass243

10 ай бұрын

If at first you don't succeed, chase puffins

@podulox

10 ай бұрын

@@wbass243Could be worse - Could be running away from polar bears...

5:02 Bigger under driven props are always quiet. We have 4 LiDAR quads and two of them are for city use, with huge props (35 center to tip) to reduce noise as much as possible so we don't get nutties aggravated when using them to map historic buildings.

@shitass3931

10 ай бұрын

35" diameter or radius propellers?

@MODElAIRPLANE100

10 ай бұрын

​@@shitass3931in case he doesn't reply let me try to help you out. He says center to tip, so it is the radius. Additionally, I think it is likely for it to be in centimeters, not inches

@shitass3931

10 ай бұрын

@@MODElAIRPLANE100 thanks. was gonna say, 70" is ridiculous lol

@shitass3931

10 ай бұрын

70cm diameter = 28" which is a common propeller size, matches up.

@EddieSchirmer

10 ай бұрын

it makes me wonder why they do not use Quad Zeppelin's. basically, a quadcopter that uses a loon style bladder to maintain neutral ounce in the air, with a mechanism to change it up or down, like a small compressor and pressure regulator sensor. then use the props to move it in the other dimensions. then it could e Super quiet, and maybe use less energy and thus have better battery range... worth testing I would say, depending on the end use I guess.

The bracing bars on the plate could have been used on the underside to act as a skirt to keep the plate higher and hence the “sticksion” from fast escaping air would be reduced

@Sandux930

2 ай бұрын

i was thinking the same thing. placing a pool noodle on each side and shaving the foam to aero shape would be perfect

Awesome build! "Generic storage container" got me off guard 😂 It's always fun to see people who hide behind lawyers get messed with. I love seeing your projects and am curious to see where they lead you to!

@ska042

10 ай бұрын

Eh, this is actually one of those situations where they kind of have to do something about it. If their brand gets used too much to refer to generic storage containers and they don't actively act against it, it puts them in a bad legal position. They might effectively lose their trademark to "generification" legally if they don't stop it.

@retovideogames

10 ай бұрын

@@ska042 Interesting. I thought, since he is not directly commercializing the generic storage container, he could call it whatever he wanted to. However, I have to admit that I know little about patent laws.

@takedown10158

10 ай бұрын

"Generic storage Container"

@titanic_monarch796

9 ай бұрын

​@@ska042I'm surprised that it isn't already a lost trademark since I hear it used near universally.

@_aullik

8 ай бұрын

@@ska042 They would be better off getting generification as that puts them in everyones mouth and as long as they produce a decent product for a decent price (doesn't have to be the best, cheapest, best value) they gonna rake in a greater profit then the competition simply because they are the go-to. If you go by a tupperware you look at tupperware first, not at no-name X. Sure you can't grow indefinitely using this tactic and if your product is shite you gonna have massives problems. However it puts you into a really solid position that you can hold for decades.

The whole "ground effect" series is quite entertaining. I guess a cheap smoke machine would help quite a lot in understanding vortexes and potential behaviors before even going on water. I think you used something similar in a previous video.

The t word company is probably fighting against becoming a generic trademark and losing rights to their cool word. In the end it's all very silly. Love the ground effect videos, keep them coming!

@iloominaty

10 ай бұрын

Just so i am not mistaken, does the T word company name also end with "ware" ?

@linecraftman3907

10 ай бұрын

@@iloominaty it starts with t and ends with upperware, correct

@up4open

10 ай бұрын

Most advertisers WANT people associating your name with the items, it keeps you on their lips. For a company in bankruptcy, that's a pretty lame way to spend cash.

@thewolfin

10 ай бұрын

Yeah this boggles the mind. If you're not cool enough, it's copyright infringement, and you have to pay the company to show their brand. If you ARE cool enough, it's product placement, and the company pays you to show their brand. Clown world.

@f3rny_66

10 ай бұрын

is not copyright, is trademark and companies are obligated to protect it or they lose it

The effect you are describing at 9:03 is the air recirculating around getting pulled through the inwash while pushing down on the top of foam boards. It goes away once you are far enough from the ground allowing the air to go straight down breaking the circulation.

ain‘t no way you can receive a cease and desist from tupperware😂😂

@FilosophicalPharmer

10 ай бұрын

What I find so funny is … these T lawyers have to make themselves useful, right? So they end up sending a C&D letter to a guy who uses their products in creative ways, has an interested audience on a popular platform, doesn’t pay advertising and now has become a joke because of the sense of importance over themselves. Upcycle Factor containers from now on, Daniel ☺️😂👍🏼

@KellanHerringshaw

3 ай бұрын

That is real lol

I really appreciate your willingness to test designs even though they may not be efficient, its really cool to see them come to life!

For stability you need to put bracing type dividers between each prop zone

Tupperware sent you a cease and desist letter???? Wtf

the reason why it "sticks" to the water when it contacts it is due to surface adhesion from the water, if you ever put a flat piece of board in the water and tried to lift it up you can feel it just stick like a weak glue

@matthewturnipseed5182

10 ай бұрын

So could you cover it in some sort of hydrophobic substance to help stave off that effect?

@colon3_

10 ай бұрын

(bear with me here) Would it lessen this effect if you were to use say a checkered pattern like a chessboard, but every black square is raised up by maybe 1/2 an inch (1cm), into a point like a pyramid??? I feel like as the tip of the pyramid tapers, the less adhesion to surface area there is.

@Terandium

10 ай бұрын

@@colon3_ I'd guess that would work yes, as there would be many air gaps and it would suck less

@crisnmaryfam7344

10 ай бұрын

@@matthewturnipseed5182 Or just use a couple two liter bottles or the like on the bottom legs to float. The foam pieces have too much surface area. For air and water applications this is bad. Unless its on a wing or prop, and used for lift. Look at some Air/Sea planes. The big boat like ballasts they have on the bottom legs/landing gear... Other people have used pool noodles, those work great on smaller drones. Not sure it would have the buoyancy for this big boy. So Id say 2 liter bottles.

@LDSG_A_Team

8 ай бұрын

Spray it with a hydrophobic coating. Boom. Problem solved.

Wait, tupawupa box company actually sent you a cease and desist for showing their product under a positive light? Incredible

@tin2001

10 ай бұрын

Probably more because he was using their name when referring to products NOT made by them.

@ckoop2464

10 ай бұрын

They would rather have us store our farts, than praise ingenuity.

@john_john_john

10 ай бұрын

@@tin2001 that makes more sense, if true. Imagine tupiwoop execs looking at their endless catalog of products trying to figure out if that box is made by them.

Cool. The best ground effect I've experienced was an MCPx hovering inverted an inch over a gym floor. It was actually hard to make it touch the floor. The tips would touch based on the angle but the center rotor button wouldn't!

What if you put your foam support pieces on the underside? Could you make air directing channels to increase stability? Anything to make it more stable than an air hockey puck. Also, it is amazingly cool to see experimental aircraft concepts play out in real life. Please keep it up.

The reason for the "sealing" might be the transition between generating lift due to pressure difference and Impuls based trust. Propellers for aircraft are designed to accelerate big amounts of air with a low pressure differential. That's also why you don't get much better power efficiency at very low altitudes, you basicly stall out the props. You should try props with more but smaller diameter blades and less pitch.

@tcveatch

10 ай бұрын

I think it’s Bernoulli. Fast air below, suction downward.

@martin09091989

10 ай бұрын

@@tcveatch Mhh.. Yea, but I think the ground effect is more or less the inverse of the bernoulli effect, or it eliminates it's effects. When the air is compresses underneath the vehicle, the fast moving low pressure air directly behing the props sucks in the air from the higher pressure underneath (in a vortex) instead of pulling it partly around the bottom of the vehicle, including from the front. I guess that's all the effects working in a complex fluid system at the same time. (maybe creating the ground effect). And the description might depend on the way you look at it. 🤔 If a day could be 4 times as long, I would love to study such things in more detail to figure out how such complex systems work, and which effect comes in and out of significance. 😅

oh hey, I used to play with that effect when I was younger ! I had on of these tiny toy quad without any automatic stabilisation that I just could not fly without crashing it everywhere, but I noticed that if I gave it just enough throttle to get off the ground (flat tiling in this case), it would hover at about 1-2 cm from the floor, self-stabilize when tilted and never really get any higher. so in the end I had a lot of fun racing my little remote controlled air-hockey puck around ^^

I’m most impressed by how quiet those big props were! I think you should do a project to make the quietest quad copter you can. Mark Rober had a video recently with a really strange prop design that was supposedly really quiet.

@crisnmaryfam7344

10 ай бұрын

Toroidal Props, though they arent all that much quieter, they shift the noise down the scale to make it "less abrasive" or less annoying to human ears. They are actually very close to normal props in terms of actual Decibel measurements. So we perceive it as quieter.

You probably though of this, but putting a reversible ESC on your forward prop would probably allow you to stop easier. Great video!

This was a really cool video with lots of different physical effects in evidence - ground effect, vortex ring state, surface tension, EM force, and quite a few others besides 😀

With your skirt at low altitude air flowing under the props has to escape to the sides, thus creating a venturi effect between water and skirt, lowering pressure and ultimately attracting your craft towards the water. Same effect as when a ship moves close to a wall or to another ship, water in between has to escape quickly and sucks both ships towards each other. This increase in speed only happens significaantly when both objects are very close to each other, and is not significant when overing a bit higher / farther from the obstacle.

@joedubois5409

10 ай бұрын

Great observation @leodurez9631 ! This is exactly why the skirt doesn't work well when it is close to the water. It is not intuitive, but the faster air is causing a low-pressure zone under the skirt and sucking the copter down, not pushing it up as desired. Remember, wings work because the faster air over the top is a low-pressure zone. In this case, you have inadvertently made an upside-down wing. Nonetheless, I love all of your videos, please keep producing and I will keep smashing the like button!

Hey, I have had success using resonance analysis tools in Solidworks to identify issues like you used the high speed camera to identify. You can compare the results of a simulation to a black box log to verify. Mechanically solving these problems iteratively in CAD is very satisfying! Love your videos sir.

The soft ceiling is probably due to a vortex from the thrust hitting the ground and circling back around to come back down on top of the blades, reducing efficiency until it powers through it.

@up4open

10 ай бұрын

I was thinking that he'd created a low-pressure zone in the center of the sheet, a bit like a vacuum. Yeah, I guess that doesn't make alot of sense when I think about your explanation. But that's some interesting phenomena as well, and should be useful for engineering something. I would venture it doesn't work while in motion?

Basically you reinvented the first hover craft. Love the projects :)

It’s sad that the company doesn’t allow you to use the t word and instead sending a cease and desist letter

Awesome video! Regarding displaying power instead of current: You could use mavexplorer (part of mavproxy) and use that to plot current*voltage, as you can easily define your own graphs there. If you do a lot of Ardupilot log analysis it's worth checking out

You should get a fog machine to visualize airflow. It would probably help explain the "soft ceiling" you mentioned at 9:00

Bought a $250 quadcopter about 10 years ago. Small/medium sized. Had a thin plastic body, that when mounted helped trap thrust air. This has the benefit of giving it ground effect flight. Hovering roughly 1-3 inches depending on power setting. Would not fly if lifted up higher. Run it off a step, and it would drop down to GE height. It gave me about 50% more flights time. I could run up and down the street/sidewalks. Clearing fresh cut grass off my drive and sidewalk. Whole time using hardly any throttle. Then had to give a decent boost of power to lift it past this GE height. Sorry, just always thought it was a neat little thing. And then stumble on this video.

The plates kill me every time 😂. They are the same ones my parents had when I was growing up and I've never seen them anywhere else. And my word, how petty of Tupper...those one people. Cool video like normal 👍.

Interesting... Maybe you may want to design something that moves weight forward when the front goes up, and same for the sizes? My brother worked on something like that in the mid 90s for the French carrier, that's how they can land planes flat in the middle of a storm: move weights.

love watching your videos as you explain all these terms in a way that's really easy to understand, while also making the video entertaining!!! I don't think i've ever clicked off one of your videos. Keep up the good work my guy.

This makes things tingle. Building something that worked closer to a jet moto style hover craft is a dream.

That's actually the best concept quadcopter in a flat platform. The blades give you flight if needed at altitudes above waves, but hover in ground effect is very efficient othertimes, speed not so important, think about what I just wrote if you want it as a four seater to go on a trip somewhere, its a very capable concept with a combustion engine. No pilot licence or airworthiness needed.

The weird middle altitude zone is probably from the top of the convex/vortexs like on a wing tip washing back down on top of it pushing it back down✓ Thanks for posting!

@bytesandbikes

10 ай бұрын

Yes, was going to say this. Winglets, ducting, or a cowl should make a big difference, up to and including the point it becomes a hovercraft!

We want a clip about a flying flame thrower for weeds that can be used with a lawn mower against zombies

8:50 Hey, it's a flying fold-up picnic table!! lol

Great video and project Daniel! Loved it all but particularly the vibration piece. Great experimenting with ground effect!

That sound profile from the huge props would be a super cool rabbit hole to go down. Would be fun to explore just how slow a prop could be turned on a quad without completely losing control authority.

3:51 someone literally gave you massive props ;)

no way! @3:00 you are one of my favorite channels, experimenting and always coming up, and now your officially recognized by insert brand name here! congratulations on officially being on the radar of such a pocket book wielding giant!

Love the use of the Pentax 50mm on modern hardware!

@KillfeedBO2

2 ай бұрын

I thought I would find someone who noticed aswell!

13:10 Had seen this process used for analyzing machines vibrations, very useful! Nice to see it available

I love your videos and generally scoff at peanut gallery comments about minor errors but if anyone wants to know… Those birds are not puffins they are coots (Fulica americana) I just live right over in Ellensburg. It’s really fun to watch your footage of Seattle.

That freefly amplify feature is pretty amazing. I know that special software exist to process and see vibration from video. Didn’t know that freefly had that feature.

How do you again and again bring i out amazing videos relating to my life? I just flew my new Quadcopter and now I'm watching this.

Big props to you Daniel!

I got to ride aboard the SR-N4 hovercraft from Ramsgate to Calais in 1969. Well, actually I was the annoying youngest child and lobbied loudly for us to use the hovercraft instead of the conventional ferry, and my parents humored me. It's telling that regular ferries are still used even decades after the opening of the Chunnel, yet the hovercraft are no more.

Need bracing between the boom arms and using a controller with betaflight and adding some RPM filters would go a long way for stability. The suction to the water was surface tension, you can stop that by adding tiny little "ice skates" to the underside so that they prevent the entire surface from touching the water at once

As I understand it, decreasing voltage means higher amperage for same power, thereby more heat for same power. If anything is seems more logical to increase voltage, to reduce heat generated for any given power output. Within the voltage range the motors and controller can handle well. Reducing voltage limits the possible power output, and thereby possible heat generation at full throttle, but it still produce more heat for a given power output. So can we hope for experiments trying to achieve low noise levels, using things like large props?

RE the floats under the props. It looks like as the props spin up, the rotation of the floats cause the water in contact with the floats to flow outwards from the float center (centripetal force). This cause the water to evacuate under the floats. You might experiment with texturing the bottom of the floats (hot iron), such that the rotation draws in water (iow make a spiral texture).

Your ground effect vehicle got this song stuck in my head. “Ain't nobody gonna break my stride, ain't nobody gonna hold me down, oh no, I got to keep on moving” 😂😂

@Anvilshock

5 ай бұрын

"Nothing", not "nobody".

I never watched your stuff before, this was fun! Also love seeing a local guy making really cool projects!

LOL I like how you went from let's see how slow we can make it move to it's not good at high speed. Awesome detail as always. Thanks for sharing this one with us. :)

I do anything to be Daniel's wingman. Give my life some meaning doing things I love. Daniel how can I help you!!!? I'd pay you to work for you. lol. Please keep it going. So glad you still can produce new things after so many years.

Interesting experiments. Thanks for taking the time to share this stuff.

i learn a hell of a lot from these videos keep up the great work man

I love these "I wanted to see what would happen when I..." engineering videos haha this is great

so funny when a company sends you a cease and desist instead of taking advantage of the free marketing.

2:50 I think one of my favorite quotes related to that kind of copyright trolling is from Adam Savage: (abridged since I can't find it) "We're going to wrap him in B***le W**P! Wait, we can't say B***le W**P? F**K!" XD

This is essentially how i teach people to manually fly quads, I get them to lift the throttle so it turns into a hovercraft and learn to control it on the floor before they add Z axis.

When the Jiggle rap dropped, this old man was laughing with gusto. Thanks for that!

Tupperware: "This is amazing we have achieved household name status." Also Tupperware: "No! Don't use out name to describe a plastic storage container!"

I love your creations, they are very cool and your process is thorough and clear. Wingspan in the case of your copter would more correctly be the length of your motor support arms I would think, but using the over sized props was a great experiment.

You've essentially just recreated a Hovercraft. The UK took the design of such to the absolute extreme, but they simply couldn't compete with other methods of transport.

i can say just by the thumbnail, that this video is gonna be great!!

Awesome video! My custom 7" frame flies in ground effect effortlessly 👌

9:30 -- The animals we create are morally equivalent to our own children. They are owed the unconditional love and protection of their creators. The experiences of animals are real and matter. Their suffering is identical in nature to your own. It harms us when we take pleasure in cruelty and violence.

I would take the T-word company sending you a C&D as an accomplishment. It's so funny a megacorp like that is soo upset over an RC boat. You know you've made waves in the ocean.

I'm so glad those propellers got some use!

Love to see the transition from ground effect quadcopter to an overpowered lift hovercraft

Really nice work - as usual!

TL:DR "Skirtless" HC's (GEHC's) do actually have skirts... kinda So, I rabbit-holed on this. The long and short of it is: you DO need a downward facing sidewall all around the underside of your deck in order to disrupt the airflow and develop a pressure cushion You ever see that experiment where you hang 2 ping-pong balls then blow between them and they get pulled together? (related to the Coandă effect) That's what was happening here and "sucking" your craft to the ground/water. Fast airflow beneath the craft creating a *low* pressure stream was defeating your lift, pulling the craft down. You need to contain that airflow in order to develop a *high* pressure beneath the craft. As it turns out, if you'd added a sidewall of just a Cm or 2 around the perimeter of the underside of the deck, it should do the trick. This is analogous to the vertical sidewalls needed on your airfoil type GEV's in some ways; containing the air beneath the craft where it can lift the vehicle rather than being knocked away without the desired lift addition.

Can't wait for the eventual Quad-rotor FPV Solid Wood RC Ground Effect Toroidal RAM-effect Foam-Wing Lawn Mower on a Car Boat Snowcat (with lasers).

My 8th grade science teacher had a "hovercraft" which was an upside-down table with a hoover vacuum, some kind of tarp that would fill with air and blow it out the bottom, a chair screwed to it to sit on, and a Hoover vacuum powering it. It was so frictionless that with extension cords we were able to coast down the whole hallway with one push.

AWESOME video as usual!!! At 8:50 I'm pretty sure the suction affect is because the closer the props and flat bottom are to the waters surface the smaller the cross sectional area the downwash has available to travel trhough (the flow under the perimeter of the craft forced through by the props). This causes the flow to accelerate and create a low pressure zone (continuity law: decrease your area increase your velocity. Bernoulli: increase your velocity, decrease your pressure. I think those are what theyre called, been a while since ive been in school haha). So the closer you get to the water, the lower the pressure becomes under the craft (kinda counter-intuitive haha). so this is also a positive feedback loop. But at a certain distance and closer, the flow is too restricted and the effect stops and the craft suction decreases. So it can sorta oscillate. I would expect you to not have this phenomenon occur when you dont have the big foam sheet, since without it, the flow free and doesnt have that perimeter curtain to be forcecthrough. Interestingly this effect is the same reason that container ship got stuck in the suez a year or two ago. It got too close to the edge of the canal and this caused the area for the water to flow past to become narrow, which lead to faster flow speed, which led to low pressure, which sucked the boat closer, then made it more narrow, more flow speed, lower pressure. you get the point. Weird edge cases of fluid mechanics where you get weird feedback loops like this are so cool :) Again, I love your videos. So inspiring! And i dont think the downwash velocity is anywhere near mach 0.3 so yall dont come at me with compressible flow XD

@jada1173

10 ай бұрын

Yes, the "suction" effect is what the formel 1 cars uses to get extra downforce on the car, lower clearance to the flat bottom of the car to the ground gives more downforce. As close as possible without touching.. Just a little touch make the car skid immediately.

I like these videos because they show *why* the peope who came before us gave up on these designs and went the route of the hovercraft: it's *much* more efficient and controllable. A hovercraft can take a hit from awave or a sandbank and jsut keep going. THe skirt makes sure of that. A low-flying plane will simply crash and kill it's occupants. It's klike watching somebody experiment with alternatives to cars and allways end up with a train.

I APPRECIATE YOU, DANIEL. THANKS FOR THE UPLOAD.

There was a uk microlight aircraft built in the 80s called the Chevron. It was designed to takeoff into ground effect, accelerate, then climb.

Really interesting! Thanks Daniel.

Yesterday, I say my friend's new Mavic mini 3 pro for the first time. It was tiny and so quiet. A real masterpiece of engineering and a work of art.

"generic storage container" was great 🤣

BTW, Hovercraft was a registered trademark by Saunders-Roe aircraft company (later Westland) so other manufacturers of commercial vehicle couldn’t be called it hovercraft, they need to be called Air Cushioned Vehicle. Speaking of Saunders-Roe, they built the first jet powered Seaplane, Saunders-Roe SR.A/1, pretty cool project.

improving the design of the skirt with holes would end up reinventing the hover craft, with its flexible skirt which makes the altitude of the ground effect higher and provide a margin of error when the waves comes closer or when the hovercraft loses altitude a bit. The hovercraft skirt makes it more efficient as well

You can play around air flow path - if you add some channeling foam pieces, position of each propeler would be either raised, or air could be distributed through saw tooth like edge skirt around. Now when one side goes up, air from rear motors will go towards less resistance path - and destabilise craft more. Without channeling/enclosure for prop wings you have a lot of pressure losess especially in radial direction, which maybe contributes to vibrations - each propeler hits wake from its neigbours. For mixed case when both pressure and volume is needed just lookup for industrial fans enclosures - they arent straight, but slightly narrowing/ rarely expanding. It allows for some design tweaking, where we would like to find sweetspot for motor efficiency and flow requrements. wrapping central unit in some foil, would reduce air resistance at fan "inlet", its not that obivous in steady flight, but in hoovering mode You calibrated stabiliser, and in horisontal flight, its adds uneven air wake for front/end fans.

I like that you don't bother pretending to keep your microwave clean for the ad

You should spray some of that hydrophopic coating on the underside of the foam panel. That will pretty much completely prevent the craft from being pulled down by surface adhesion if it happens to touch the water.

Great! I would love to hear more about quiet quad concsepts!

The ground effect King has blessed us once again 🙏

keep the good work going!

Reminds me of the difference between a direct drive speed 400 and going to GWS gear drive’s with huge props back in the brushed days lol. Went from sounding like a weed whacker to a ceiling fan lol

8:51 surface tension. I feel so smart now that I knew something this guy who builds freaking drones didn't :D

The large props on mismatched motors were probably less efficient due to I^2*R losses not magnetic saturation. Saturation means the torque stops increasing when current is increased above saturation current. This means the flight controller would not be able to maintain control no matter how the PIDs are tuned because the motor would not be able to achieve the requested rpm. When the quad responds to a pitch disturbance the motors on one side can slow down but the motors on the other side wouldn't be able to speed up and even if it could stay level it would lose altitude. A higher Kv motor has lower Kt regardless of motor size. Kt=1/Kv in Si units no matter the motor size. Bigger motors are thought of as higher torque because they can handle higher current without burning the winding or saturating the stator. A huge motor and a tiny motor make the same torque with the same current if they are the same Kv, the big motor needs (and can handle) more current to make more torque. Big motors also have smaller winding resistance so they will draw more current at the same voltage. That means having high Kv motors on large props will use more current than properly matched Kv motors on the same props. And it's important to have fairly close matched motors and props because motor heating goes by the square of the current (I^2*R), so having 2x too high Kv means 2x higher winding current and 4x more motor heating and inefficiency. Running the high Kv motor on lower battery voltage does not fix the problem that the big props need more torque (and current) to spin. The reason quads use higher voltage than the motor requires for the target prop rpm is because peak current is determined by winding resistance so running more voltage will allow higher current spikes and more responsiveness to disturbances like gusts. Basically it means you can achieve a better PID tuning. The esc pwm duty cycle and motor inductance act as a buck converter. If a 100kv motor needs 10v to spin 1000rpm, and the battery is 20v, that means the pwm will be 50% duty cycle. That also means the motor current will be 2x battery current since power is conserved. For example, if the motor needed 2 amps to spin the prop 1000rpm, the battery current would be 1amp in this example. So running extra battery voltage also lowers battery current (but does not change motor current). Since this buck converter effect is not actually 100% efficient, and higher step down buck converters are less efficient, this is why you don't just run as high a battery voltage as you want. It took me years to fully understand everything I just said because some of it goes against intuition we have as RC hobbyists. We all know if 2 different size motors have the same Kv the bigger one will make more torque, but that's because it's drawing more current, if Kv is the same Kt is the same too. We've also all put a higher Kv motor in our model and got higher speed and torque, although I just said a higher Kv motor has lower Kt. The reason for that is the higher Kv motor has so much lower winding resistance it can draw enough current to overcome the lower Kt.

8:53 it might the becourse weird things like bernoulli effects, the flat surface interactions between the foam and the water, if the air flow faster some places it should create some form of "suction" between them making it feel sticky. 9:00 maybe see if you can interduse some smoke and one of those flat lasers. Maybe you make giant vortexis that swirl around like big helicopters do, the big plate probably amplifies the effect they course. Wen you get far enough up they probably destabilis course no more rebound of air from ground?

13:11 This tech needs to be 'tested' at the beach, gym or even a dance studio for human kinematics studies. 😎

As soon as I heard the word "jiggle" I knew a song was coming, but I figured it would be another remake banger.

it sticking to the floor and in that weird 3foot spot looks a lot like what the Coriolis effect does. Not sure how to apply it, but it just looks like it. Awesome video!

The “soft ceiling” you mentioned the skirtless version has is exactly what you’d expect for a working ground effect.