B1 Intermediate US 11 Folder Collection
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I saw this video on Twitter with over five million views and then again on YouTube with nearly 1 million views
Basically, this guy modified his cellphone case with propellers to take selfies
Which is awesome my only issue with it is that it's not only fake, but it's a scam which I'll explain in a minute
but as for being fake
The first clue is that these are three volts seven millimeter micro brush motors like you see here if you attach one to a beam
Like this and turn it on at full throttle you'll see the most weight that it can lift is six quarters or about thirty grams.
The cell phone in the video with all the flying gear attached would weigh about 300 grams
and since drones are typically designed to hover at 70% max thrust you would need at least
15 of these motors to do what he did, but you know, this just doesn't look as catchy
In fact, we recreated the exact setup
he used in the video and turn the motors to full throttle and this is what happened here.
Here it is in slow mo and as you can see there's hardly any difference than if you don't turn the propellers on at all
so I'm gonna show you how this scam artist somehow manages to break the laws of physics four more times in this three-minute video and
then because obeying laws of physics isn't optional
we're gonna call a fellow youtuber Captain Disillusion to see if he can help us spot any signs of a special effects. And then
with my buddy Peter Sripol i'm going to show you what it would take to
Actually build a flying selfie phone case and then i'll put all the details on a new set. I built using wix.com.
But, before I do any of that
let me first explain why this is a scam and not just a harmless fake video for meaningless internet points. With this many views and
An astounding 80% like ratio, which means most people probably didn't realize it was fake
It's a statistical certainty that some young aspiring engineer
actually tried to build this themselves
worse than their parents phone dropping like a rock and breaking
this might have been his or her first experience at making something. But, how you might ask would they know what components to use well?
here in the description amazing maker was kind enough to put links Amazon affiliate links
you can tell by the URLs.
So he is making money off the crushed dreams of aspiring engineers without enough experience yet to this is total BS and aspiring engineers
are my people, and you don't mess with my people.
Let's do this
the second gratuitous violation of physics comes in this scene the force of gravity always points down but helicopter spinning blades create a force perpendicular
to the blades themselves
so if you want to hover you need to be level so the forces will cancel out and you won't move if you tilt forward
and then break the thrust force into its x and y components
you suddenly have an unbalanced force that will move you in that direction in essence
that's how helicopters move forward by tipping forward in other words
It's physically impossible to hover in an orientation like this
The forward thrust component is unbalanced and it would have to move the phone forward
The third major issue is the Arduino compatible circuit board
he chose. It's the same board here and it's supposed to be the brains for the drone
yet, this specific model of board doesn't come with any sort of gyroscope or accelerometer.
Here's why that matters if you've ever tried,
balancing something on your hand like this you and your body we're creating what's referred to as a closed-loop feedback control system.
So if it starts to tip over my eyes relay that to my brain and my hand says hey
I'm no longer fuelling the weight just up and down
it's also pushing my hand this way and so my brain takes all that information and
responds by telling my hand to move this way at a specific speed in order to compensate.
So, to keep this thing balanced there's this continuous loop of quickly gathering information and then making real-time adjustments and closed feedback
loops are used all over in engineering from the simple case of a thermostat that
continuously checks the air and turns on at a certain temperature to
dart boards that update their position 200 times a second to get a bull's-eye every time
to machines that are abused and most certainly for anything that flies and needs to stay in the air the fact that his board is
missing a gyroscope and an accelerometer
means there's no way for it to tell if it's starting to rotate or to fall in any direction
It's the equivalent of trying to balance the board wearing a blindfold and an oven mitt
you have no idea what adjustments to make to keep things balanced. Which is the perfect lead-in to the fourth major physics
Flaw notice how he attaches these motors and rigidly fixes them to the phone double-stick tape
this means if you start to tip forward
you have no way to self-correct the phone
orientation and it would just turn into a nosedive, if you only have two propellers in this configuration
they both need to be able to rotate with respect to the phone in order to correct the movements in all six degrees of freedom
for example if it starts to tip forward
you could rotate them both back like this
to correct for that. Or if the wind is trying to spin the phone this way they could assume this configuration to
counter that to return to our balancing shovel analogy by fixing the motors directly to the case
you lose your ability to even make corrections
so not only do you have no idea where to move, but your arm is locked out for making adjustments anyways
which makes it literally impossible to balance.
My final physics issue with this video is one of acoustics
this guy proposes using it as a hands-free way to watch your favorite super hip music videos
conveniently dubbing over the audio here
for reference this is what an episode of the office would sound like on a phone at full volume
and don't forget that you would actually need 13 more motors than this so it would be at least six times louder. [Extremely Loud Whirling Sound]
So now that we thoroughly established a multitude of physical laws have been broken.
Let's find out exactly how he faked it and to do that
I've arranged video call with the undisputed heavyweight champion of the bunking fake videos using special effects Captain disillusion
Be sure to get it as flush as possible against your skin to minimize folds that might make it hard to
chroma key out like this
nice and tight
Captain oh hi Mart Mart robber you weren't supposed to call yet. It's 2 o'clock
I'm actually even 5 minutes late, really.
Well then.
How can I help you
did you not even watch the video I sent
ah, yes, of course the mobile drone video
I've analysed that thoroughly mark and my conclusion is it's totally real
Seriously, yes
Everything except for the mobile drone part, that's fake
if you look very
You might just be able to make out the huge
chattering mask on the side of the phone
Visible in every shot of it flying the creator must have been in a real hurry because it's so messy here
it cuts off the edge of the phone here the tip of his finger and here it reveals the thing
it's supposed to be hiding a rod. It's narrow and light-colored and probably attached with the same mounting tape
He used to tack on all the other gadgets
That's why he's able to grab and adjust the phone in this shot by the river the mask hides not just the stick
But the whole person holding it look closer on this site the real-time
Water and on this side a still frame from an empty version of the shot
And if we track the phone's position and rotation we can easily
Reverse-engineer exactly how the stick puppeteer did rotating mostly from the point where it was held
That was very impressive captain D
Thank you for taking the time favorite part of this whole thing is the audio
The tiny propellers must have made so little noise at a distance. It didn't give a proper drone vibe
So the hoaxers recorded the sound of the motors up close and reused the same clip in every scene
complete with their muttering voices in the background
[Whirling Noise and Muffled Voices]
Awesome well, thanks again.
But, even though impressive is the number of posts messages and tweets
Presumably from people with functioning eyeballs asking me if this painfully obvious edit is real over and over.
Okay, captain will take care. I've got to go back to my even you mark how could you do this to me?
How could you do?
He's such a joker. So let's fake and now you know
exactly all the reasons why but still a really interesting idea and I was curious what it would look like if you actually
built one of these at using less special effects and more practical engineering.
So, naturally I called in my buddy Peter Shree people whose qualifications
Include building his own electric flame from scratch and he immediately got to work.
Turns out if you take two brushless motors to electronic motor speed controllers a flight controller that actually has a gyroscope and an accelerometer
Integrated a 3d printed frame and two servos to articulate the rotors a radio
transmitter for remote control and a force the lipo battery and then you put them all together it actually works.
Kind of we had to do a bunch of test flights to calibrate that
Feedback control loop we talked about before
so if we notice the drone is either under
compensating or over compensating when it starts to fall in a certain way
we tweak the response
sensitivity in between flights until we get to the sweet spot and I should mention remember how the motors from the fake video could barely
Lift only six quarters. Well, if you properly sized them for the task at hand, they should be able to lift 150 quarters.
And so once we felt like we had it in pretty good shape. We took her out for the maiden test flight
[Music Plays]
They in our defense it was a little windy out there
but as you can see, it can be pretty wobbly at times the truth is a bike copter like this totally works
it just isn't a great design choice.
The reason pretty much all camera drones are quad copters is because they're much more stable due to a larger footprint shared between four motors
and by getting clever with the throttle speeds you can move in all six degrees of freedom with no moving parts
So there you go with solid engineering. You don't need hidden rods or masking and rotoscoping and Sir Isaac Newton can once again
comfortably rest in his grave. So, the moral of the story is just don't cheat and lie in scam
I actually considered going a little easier on Amazing Maker
but then I happen to scan some of his other videos like this knee brace that
Charges your phone and even powers this flashlight as you walk in theory
I'll skip the details
but in reality this system would also never work as shown which is why if you whine that and stabilize on his hand in the
pocket you see him click a hidden flash light switch.
If you want to build a flying selfie foam case yourself
you can watch the video Peter made with all the juicy details. You can find that on his channel or new website
I created called mark rover build instructions.com, and on that site and
you'll actually see build instructions for tons of different projects from my channel, which was made possible by the fine folks at wix.com
I wanted something simple and classy and I almost feel a little guilty
I can make something dysfunctional and it only took about an hour in part. Thanks to a series of questions
you answer when you get started
that means right off the bat
you're close to what you want,
but you can still customize it as much as you like from there
including lining it with one of the hundreds of templates they have and my website is just a simple way to communicate information
but you can make one for your personal brand or your
portfolio, or maybe a new website for your business to sell stuff, or even book appointments right there. And it's free to sign up to
start designing and publishing and it's honestly a lot of fun.
So, to flex your creative muscles for the whole world to see go to wix.com
Slash go slash mark rover or use the link of the video description to get started
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11 Folder Collection
彭成豪 published on July 1, 2020
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