- 5 hours ago
Category
📺
TVTranscript
00:00This is a friendly robot that's impossible to beat a rock-paper-scissors.
00:03This is an infinite slinky staircase that can run for days.
00:07And this is basically a room temperature ice rink.
00:09Today, we're not only going to count down 10 of the coolest things we've built at Crunch Labs over the past year,
00:14but we're going to also break down the science of how they work,
00:16and even show how you can easily recreate a few of them yourself.
00:19Starting off at number 10, when you need to let everyone know it's lunchtime,
00:22typically you'll have something like this.
00:25But that's boring.
00:26So we replaced it with this.
00:27A choir of 22 screaming chicken heads.
00:30It's long been established that if you ever see these in a bin at a store,
00:33after you apply a little pressure,
00:36it will yield amazing results.
00:44Beautiful.
00:45Now to find out why, we just need to take a look inside.
00:48And when you do, you'll find this.
00:50It's basically just a kazoo or one of those party blowers.
00:52So after squeezing the chicken,
00:54it expands back to its original shape,
00:57which pulls air over this diaphragm,
00:59causing it to vibrate and make that terrible, terrible noise.
01:03So then if you just hook up all 22 to an airline pressurized at 100 psi,
01:07then you turn this valve,
01:08everyone knows,
01:13it's lunchtime!
01:16Coming in at number 9,
01:20if you happen to discover a platinum ticket in your Crunch Labs box,
01:23securing you a free trip out to Crunch Labs,
01:24well then it's very likely our own science Bob will show off his fancy deflagration tube.
01:31Basically, you load in some gas and then ignite it,
01:33and it creates a slow-moving wave of fire that spreads because of heat.
01:37And we call that a deflagration wave.
01:39And once it's almost done tracing all through the tubes,
01:42it approaches the end here,
01:44where the gas and flame mix with the oxygen,
01:46making a small explosion.
01:47And since the bottle is in the way of the quickly expanding gas,
01:51it goes along for the ride.
01:53Bullseye.
01:53Now that's only the first two of our countdown to number 1,
01:56but number 8 is where things really start to get interesting.
01:59Because if you take 3.5 million Airsoft PBs,
02:02it just swallows you,
02:03and then knock them over,
02:05you basically make a room temperature ice rink.
02:11This was honestly the most slippery surface I've ever stood on.
02:15Isn't it true?
02:15This is crazy.
02:16As you can see here,
02:17it's almost completely frictionless,
02:19even more slippery than ice,
02:22which means it should be perfect for skating.
02:29And while we had a lot of fun surfing,
02:36skating,
02:37and even bowling,
02:38it was ultimately incredibly difficult to keep our footing.
02:45Like, no way to stop.
02:46So we decided to call in a pro.
02:50This is Anna.
02:52And she's a 10-year-old skateboard competition winning legend.
02:57Are you doing a shove?
02:59I was doing a kickflip, obviously.
03:00Oh.
03:02And she absolutely dominated the BB floor.
03:05Hey!
03:05But could she pull off the impossible jump?
03:15Ow.
03:15I think I broke all my bones.
03:17And what makes Anna so great...
03:19Ugh.
03:21Ugh.
03:24Oopsie.
03:24...is that she's incredibly tenacious.
03:26Can I still land it or no?
03:27And she never gives up.
03:29So before she takes her final shot at nailing this trick,
03:32we need to discuss the science behind this room temperature ice ring.
03:36Because intuitively,
03:36it should make sense why this blue ocean is so frictionless.
03:39Because any given BB rolls smoothly on the ground,
03:42and your foot rolls smoothly on top of the BB.
03:45So when you have hundreds of these underneath you,
03:47it's like you have hundreds of perfect wheels
03:49to slide you in any direction.
03:51And what's really cool is if you take the floor and replace it with metal,
03:55and then take your foot and also replace it with metal,
03:57then you just connect the top surface to itself like this,
04:00and the bottom surface to itself like this,
04:02well now they'll still slide relative to each other,
04:05just as good as my foot does with the floor.
04:07And this is exactly how ball bearings work.
04:10And besides being just in your fidget spinner,
04:12ball bearings are everywhere.
04:13They're in your bike, skateboard, and roller blade wheels,
04:16where the wheels connect with the axles.
04:18You'll also find them in aircraft engines,
04:20washing machines, and a bunch of other tools.
04:22Pretty much anything you see that rotates,
04:24where smooth, low friction is required,
04:26will have ball bearings that work just like this floor.
04:29Another really cool thing we discovered
04:31is that when you interact with all the BBs,
04:33they almost behave like water would,
04:35even though they're totally dry.
04:36And this actually makes sense,
04:38and it's sort of what you would expect,
04:39because when computers have to simulate water
04:41in order to predict how the water would interact,
04:43they break it down into particles like this.
04:45And although it's not a perfect one-to-one match
04:47for a bunch of actual physical BBs,
04:49they are governed by many of the same forces,
04:52so they end up looking very similar.
04:53Now back to Anna for her final attempt.
05:03And now that we've all survived number eight...
05:14I'm dead.
05:15...coming in at number seven were these chairs.
05:17But what makes them really cool
05:19is they're made from one single sheet of continuous plywood.
05:22So you start with the sheet of plywood like this,
05:24then you give it a paint job,
05:25then you place it on a CNC router machine,
05:27and you have it cut into this very specific pattern.
05:30And after that, you just take out the middle part
05:31and then fold it into an actual functional chair.
05:35Now, it's weird to think of wood as foldable and bendy,
05:38but this is another example of a compliant mechanism,
05:40which, as you recall from my World's Smallest Nerf Gun video,
05:43is when you could take advantage of the fact
05:44that even solid materials can flex and bend
05:47if you give them the right shape.
05:48And just like with the World's Smallest Nerf Gun,
05:50this chair was designed in the BYU Compliant Mechanisms Lab.
05:53And there's a 3D printable file in the video description
05:55if you want to assemble your own mini single-part foldable chair.
05:59Now, number six is your key to being the coolest person
06:02at your end of summer block party.
06:03Because right here, you've got a vinyl tube
06:05that's ready to spit out water,
06:06and it's connected to a subwoofer speaker.
06:08So now if you turn on the subwoofer at 30 hertz,
06:10which means it's vibrating up and down 30 times per second,
06:14it wiggles the tube up and down at 30 times per second.
06:17But then if you set your phone camera
06:18to record at 30 frames per second,
06:20it makes the motion virtually undetectable.
06:23So when you squirt some water through the tube
06:24and start the speaker,
06:25your camera's only taking pictures
06:27when the wave is at this exact position
06:29every 1 30th of a second.
06:31So when you play it back,
06:32it looks like a frozen wave of water.
06:35Now what's really cool is if you change the subwoofer frequency,
06:38say to 31 hertz or 31 times per second,
06:40now every 30th of a second,
06:42the picture of the water wave
06:43is just a little further forward.
06:45So it makes it look like the wave of water
06:47is slowly traveling forward.
06:48And of course, reducing the frequency
06:50has the opposite effect.
06:51And if you're smart about it,
06:52this can make you look like an absolute wizard.
06:55But if you can use one speaker
06:56to make the wave go up and down,
06:58theoretically, if you added a second speaker
07:00and you made the wave go side to side,
07:02the combination should give you a spiral.
07:04And sure enough, it actually does.
07:07Now all that's left is to play a sick beat
07:09to celebrate the W.
07:10Now this is sort of an extensive setup,
07:35but what's really cool
07:36is you can make a very simple version of this yourself
07:38and all you need is a hose,
07:40some tape,
07:40a cordless drill,
07:41and a bit.
07:42Start by folding the tape into a flag
07:44to provide an offset weight.
07:45Let's secure the hose to the bottom
07:47of the cordless drill
07:47and when you turn them both on,
07:49you'll find the natural vibrations
07:50of the spinning drill
07:51cause the hose tip to rotate in a circle
07:54near the magical 30 times per second rate.
07:57And then changing the speed of the drill
07:58slightly with the trigger
07:59will cause the wave to change directions.
08:01Honestly, how cool is this?
08:03Now a lot of people confuse
08:04what you're seeing here
08:05with the really cool phenomenon
08:06called laminar flow,
08:07but they're different
08:08because this is laminar flow.
08:11It's where the layers of a fluid interact
08:12by sliding over one another
08:14in a predictable pattern
08:15instead of going turbulent
08:16and unpredictable.
08:17The big difference
08:18is what you see with the speaker
08:19is only impressive
08:20through the camera feed
08:21because the frame rate
08:22matches the wiggle rate.
08:23With laminar flow,
08:24it looks cool
08:25even real time
08:26with your own eyes.
08:28And once again,
08:28the good news is
08:29you can make a simple version
08:30of this yourself too
08:31if you just get a balloon like this,
08:33fill it with water,
08:33tape a tic-tac-toe square like this,
08:35and then give it a good cut
08:37right in the middle.
08:37And as you can see here,
08:38even with these really simple materials,
08:40it looks like total magic.
08:42The next two inventions
08:43are pretty quick and simple
08:44before we make it
08:45to our final three absolute bangers.
08:47Starting first at number five
08:48with this heavily modified Roomba
08:50because every single month
08:51we place a platinum ticket
08:52inside one Crunch Labs build box.
08:54And if yours has it,
08:55I got it!
08:56you're coming out here
08:56to Crunch Labs in person.
08:58And while you're here,
08:58it's very likely
08:59we'll have a very fun
09:01epic nerf gun battle.
09:08What's not so fun, however,
09:10is the epic cleanup
09:11required afterwards.
09:12But why clean up a mess
09:14when you can just
09:15invent a robot
09:16to do it for you?
09:17So by taking the front
09:18of one of these
09:19acorn pickruppers
09:20and 3D printing an attachment
09:21to secure it to a Roomba,
09:22things get much, much easier.
09:25So with only the occasional
09:26empty of the chamber,
09:27I could spend my time
09:28working on coming up
09:29with other ideas.
09:30Ideas like number four
09:32because over the years,
09:33myself and Crunch Labs
09:34have received a few awards
09:35and it feels too weird
09:36to put them on display
09:37in the front lobby
09:38in a trophy case,
09:39but it also seems disrespectful
09:41just to leave them
09:41in a dusty bin.
09:42So the middle ground
09:43is if you stand right here
09:44and pull this unmarked handle.
09:46It uses a 6-to-1
09:47mechanical advantage
09:48pulley system
09:49to rotate this mere
09:5045 degrees into place.
09:51And now if you just so
09:52happen to look up
09:53standing only in this
09:54exact spot,
09:55you can admire the hardware.
09:56And that brings us
09:57to the final three,
09:58starting with Simon,
09:59one of the most beloved
10:01games of my childhood.
10:02Basically, it lights up
10:03one of these pads
10:04and then you just have
10:05to repeat it back
10:05by pressing the same pad.
10:08And that's easy enough,
10:09but each time
10:09it adds another pad
10:11to the padder,
10:12which is not so bad
10:12at first,
10:13but then it starts
10:14to add more and more
10:15and get faster and faster.
10:19Dang it!
10:20Just as frustrating
10:21as I remember.
10:22I think the farthest
10:22I ever made as a kid
10:23was like level 13,
10:25but lucky for me,
10:26I'm now an engineer,
10:28which means I have
10:28a very particular
10:29set of skills.
10:30Skills I have acquired
10:32over a very long career.
10:34Skills that make me
10:35a nightmare
10:35for games like these.
10:37So if we place Simon
10:38right here
10:39and then take some inspiration
10:40from this incredible
10:42cockroach trap,
10:43we can add four posts
10:45around the perimeter,
10:47each with their own
10:47drumstick, rubber hand,
10:49and high torque servo motor.
10:50So these can be
10:51our pad smashers,
10:52but now they need to know
10:53which pads to smash.
10:55For that,
10:55we've just got a simple
10:56webcam here that runs
10:57a Python script
10:58from a Raspberry Pi,
11:00and it ignores everything
11:01in the camera field of view
11:02except for these four
11:03small rectangular portions
11:05where the bulbs are.
11:06And so when the color
11:07suddenly intensifies
11:08in any one of those rectangles,
11:10you know that's the pad
11:11that needs to be hit.
11:12So once you store
11:13those pad hits in memory
11:14to be played back,
11:15the game becomes really easy.
11:18Like, violently easy.
11:20Here we go.
11:21So now, all we had to do,
11:22good,
11:23was get through
11:24all 32 levels of Simon.
11:26Level 3 for your A game.
11:27And while 32 seems like
11:28a random number of levels,
11:30there's actually a reason for it.
11:31Turns out in 1978
11:33when this game was made,
11:34bits were expensive.
11:35And the number 32
11:36is the exact highest number
11:37you could count to in binary
11:39if you only have
11:40five bits to spare.
11:41After five minutes,
11:42we're halfway there.
11:44So while my pad smashing robot
11:45avenges all my childhood losses,
11:47I just want to point out,
11:49just like all the things
11:50you've seen in this video so far,
11:51my favorite thing
11:52about thinking like an engineer
11:54is you can basically make
11:56whatever you can dream up.
12:01And if you want to start
12:02developing this skill yourself,
12:04Crunch Labs has you covered.
12:05Because for kids,
12:06we've got Build Box,
12:07and then for teens and adults,
12:09we've got Hack Pack.
12:10In both cases,
12:10they get delivered right to your door
12:12where we build them together
12:13and learn all the really cool physics
12:14that make them work,
12:15plus all the fundamental tools
12:17you need in your toolkit
12:18to start creating
12:18your own projects and inventions.
12:21Oh, baby.
12:23That's level 27.
12:25Five more to go.
12:26So this holiday season,
12:27if you or someone you love
12:28wants to take the first step
12:29of unlocking the really fun
12:31and rewarding hobby
12:32of making stuff,
12:32Crunch Labs!
12:34Yeah!
12:35Just scan this QR code
12:36or head to crunchlabs.com.
12:38Final level!
12:39Let's go!
12:40Feels like a moment.
12:41So after 10 minutes
12:48with a bit of a robotic assist,
12:50I'm happy to say...
12:51Yeah!
12:52I finally beat this dumb game.
12:54Ha ha ha ha!
12:56We did it!
12:57Give me some.
12:58Blue, red, green, yellow.
13:00On to number two.
13:02And that's this little guy.
13:03His name is Rocky,
13:04and he's a robot
13:05who's really, really good
13:06at only one thing.
13:07Dang it.
13:09But before I show you
13:10just how good,
13:12if you don't happen
13:12to have a rock, paper, scissors
13:13robot yourself,
13:14you should know
13:14there's a trick you can use
13:16playing against other humans
13:17to win 75% of the time
13:19because a few years back,
13:20researchers studied
13:2154,000 games of rock, paper, scissors
13:23and discovered a pattern.
13:24If your opponent wins,
13:26they're slightly more likely
13:27to stay with their previous choice.
13:29And if they lose,
13:29they're slightly more likely
13:30to shift their choice
13:31to the next in line
13:32of rock, paper, and scissors.
13:34So here's all you need to remember.
13:35If you win,
13:36go to the next one in line
13:37in order of rock, paper, scissors.
13:39So if you beat them with rock,
13:40play paper next.
13:41If you beat them with paper,
13:42play scissors next.
13:43And then if you lose,
13:44go backwards in the line
13:45of rock, paper, scissors.
13:46So if you lose with scissors,
13:47play paper.
13:48And if you lose with paper,
13:49play rock.
13:50So just remember,
13:51move forward if you win,
13:52move backwards if you lose.
13:54Now of course,
13:54that doesn't mean
13:55you'll win every game,
13:56but it does increase your odds
13:57by 10% for any given game.
13:59So if you just play best of 20,
14:00those odds add up
14:01and you'll win the series
14:0275% of the time.
14:04As a man of science,
14:05I actually tested this myself
14:06and it totally worked.
14:07Again,
14:08I didn't win every game,
14:09but it just gave me a slight edge,
14:11which is all it took.
14:12Now as for beating Rocky,
14:13sadly,
14:14regardless of your strategy,
14:15your chances are much,
14:17much lower.
14:18Rocky!
14:19As in 0%.
14:20And that's because Rocky
14:21not only tracks the position
14:22of my hands,
14:23so he matches my movements
14:24up and down,
14:25but he checks the position
14:26of my fingers
14:27100 times per second
14:28using an IR hand motion detector
14:30and a mini computer
14:31to determine what I'm throwing.
14:33And then once the computer knows,
14:34it tells the correct servo motors
14:36in Rocky's 3D printed hand
14:37to actuate
14:38to throw the winning shape.
14:40Now as you can see,
14:40whether I go slow
14:42or I go fast,
14:45he somehow always wins.
14:46The first person
14:47to beat him fair and square
14:48gets the $10,000 cash briefcase,
14:50but honestly,
14:51I think your chances
14:52are still better
14:52at just hitting the bullseye
14:54with the American Gladiator's
14:55tennis ball cannon.
14:56And finally,
15:00we made it to the number one
15:01coolest thing we've built
15:02at Crunch Labs
15:03over the past year,
15:04the Infinite Slinky Staircase.
15:06Like most good inventions,
15:07the Slinky was invented
15:08by accident in 1943
15:09by a naval engineer
15:10who inadvertently knocked
15:11a stabilizing spring
15:13off the shelf
15:13and noticed how it walked down
15:15instead of falling straight off.
15:16So he and his wife
15:17decided to make a toy out of it,
15:18call it a Slinky,
15:19and now 80 years later,
15:20over 300 million
15:21have been sold.
15:22And as a kid,
15:23I loved Slinkies,
15:24especially trying to see
15:25how many stairs in a row
15:26I could get it to climb down,
15:27with my record sadly
15:28being only seven or eight.
15:30So naturally,
15:31now that I'm an engineer,
15:32it was time to avenge
15:33this childhood frustration.
15:34The first thought I had
15:35was using a treadmill
15:35tilted at just the right angle.
15:38The problem with that
15:38was there was
15:39very little repeatability
15:40because the landing surface
15:41was inclined like a ramp,
15:43unlike actual stairs.
15:45So to solve that issue,
15:46we tried an actual escalator
15:47and that worked a little better,
15:49but the distance
15:49between the steps
15:50wasn't ideal
15:50and the speed
15:51was a little too slow.
15:52And that's when
15:53we just decided
15:53to make our own prototype
15:54of an escalator,
15:55I could turn
15:56with a hand crank.
15:57Fun fact,
15:57this is how escalators
15:59actually work.
16:00You don't normally
16:00think about it,
16:01but these stairs
16:02are making a round trip,
16:03so they're coming up
16:04below you like this
16:05upside down
16:05as you make your way down.
16:07And that prototype
16:08worked well
16:08because we got
16:09the stair spacing dialed in,
16:10but we were having issues
16:11keeping the Slinky aligned,
16:13which is where
16:13these 3D printed
16:14self-centering cones
16:16came in handy.
16:17Because if we put
16:17one on each stair step,
16:19the Slinky would self-align
16:20and then be in the
16:21perfect position
16:22to fall to the next step.
16:23Finally, we got rid
16:24of the hand crank
16:25by adding a motor
16:26with the speed controllers
16:27that varies the voltage
16:27so we could get
16:28the timing dialed in
16:29just right.
16:30And that was almost perfect,
16:31but it turns out
16:32the speed of the Slinky
16:33sort of varies slightly
16:34over time.
16:35So now that the
16:35dutiful prototype
16:36had served its purpose,
16:37we made a final version
16:38that looked beautiful
16:39and had a time-of-flight
16:40proximity sensor on the front,
16:42so we would run
16:42a closed feedback loop
16:44to change the speed
16:45of the motor
16:45to ensure the Slinky
16:46was always right
16:47in the middle of the staircase.
16:49And when you do all that,
16:50you get this.
16:51But before the official demonstration,
16:52you should know what I think
16:53is the coolest thing
16:54about a Slinky.
16:55Because if you let one
16:56hang down like this
16:57and then let it go,
16:58the bottom stays perfectly
16:59still in one spot
17:00because it's balanced
17:01between gravity
17:02and the tension force
17:03pulling it up.
17:04And that tension force
17:05pulling up stays unchanged
17:06until the wave
17:07finally propagates down.
17:09At which point it's like,
17:10oh, I guess I'm supposed
17:10to fall now.
17:11And so without further ado,
17:13here it is.
17:14What's really cool
17:18is once it's running,
17:19you can push either
17:20of these two buttons
17:21to temporarily slow down
17:22or speed up the staircase,
17:24after which the sensor
17:25takes back over
17:26to adjust itself
17:26back to the middle.
17:27Now, given that my childhood
17:28record was eight steps,
17:30I'm just going to leave
17:30this running
17:31to see how much
17:32I can beat that vibe.
17:33All right.
17:42This has now been running
17:43just over 48 hours,
17:45which means that Slinky
17:46has traveled
17:47just over 208,000 stairs,
17:50which is just over
17:5229,000 times more stairs
17:54than I ever got as a kid.
17:56So I'm calling that a W.
18:00In my ongoing quest
18:01to be the favorite uncle,
18:03I've tried quite a few
18:05things over the years.
18:09Who's your favorite
18:10uncle?
18:10My name!
18:12But now I finally
18:12discovered a much
18:13easier way so you too
18:15can be the favorite uncle
18:16or aunt or even parent
18:18by simply gifting
18:19a young person
18:20in your life
18:21a Crunch Lab's
18:21Buildbox subscription
18:22for the holidays.
18:23Mark Rover is one
18:24of his kids!
18:25So it gets delivered
18:26right to their doorstep
18:27and then we build
18:28the really fun toy together.
18:29It's basically like
18:30unlocking your own
18:30personal Mark Rover video
18:32every month
18:32where you learn
18:33a new engineering principle
18:34that will have you
18:35not just building
18:35like an engineer
18:36but more importantly
18:37thinking like an engineer.
18:39So you're developing
18:39resilience and
18:40problem-solving skills.
18:42Which means someday
18:42you too can be
18:43building robots
18:44to avenge your
18:45childhood frustrations.
18:46Not only that,
18:47but each month
18:47your box has a chance
18:48to contain the
18:49platinum ticket.
18:50And if you get it...
18:50platinum ticket oh my god!
18:52Well then you're coming
18:53out to Crunch Labs
18:54to build with me
18:54and my team for a day.
18:56So if you want to
18:56grow your brain
18:57in really fun ways
18:59with me
18:59just head to
19:00crunchlabs.com
19:01or use the link
19:02in the video description
19:03where we're giving away
19:04two months free
19:04as a holiday special.
19:06Thanks for watching.
Comments