My Rock, Paper, Scissors Robot Never Loses (+9 Other Inventions)

This is a friendly robot that's impossible to beat at rock, paper, scissors.

This is an infinite slinky staircase that can run for days.

And this is basically a room temperature ice rink.

Today we're not only going to countdown ten of the coolest things we've built at CrunchLabs over the past year.

But we’re going to also break down the science of how they work, and even show how you can easily recreate a few of them yourself.

Starting off at number ten, when you need to let everyone know it's lunchtime, Typically, you'll have something like this but that's boring So we replaced it with this a choir of 22 screaming chicken heads.

It's long been established that if you ever see these in a bin at a store, after you apply a little pressure it will yield amazing results.

beautiful Now to find out why...

We just need to take a look inside.

And when you do, you'll find this.

It's basically just a kazoo or one of those party blowers.

So after squeezing the chicken, it expands back to its original shape, which pulls air over this diaphragm, causing it to vibrate and make that terrible, terrible noise.

So then if you just hook up all 22 to an airline pressurized at 100 p.s.i, then you turn this valve...

Everyone knows It’s lunchtime!

Coming in at number nine.

If you happen to discover a platinum ticket in your CrunchLabs box, securing you a trip out to CrunchLabs Well, then it's very likely our own Science Bob will show off his fancy deflagration tube.

Basically, you load in some gas and then ignite it, and it creates a slow moving wave of fire that spreads because of heat.

And we call that a deflagration wave.

And once it's almost done tracing all through the tubes, it approaches the end here, where the gas and flame mix with the oxygen, making a small explosion.

And since the bottle is in the way of the quickly expanding gas, it goes along for the ride.

Bullseye!

Now that’s only the first two of our countdown to number one But number eight is where things really start to get interesting.

Because if you take 3.5 million airsoft BBs it swallows you and then knock them over You basically make a room temperature ice rink This was honestly the most slippery surface I've ever stood on.

Isn’t it trippy??

This is crazy.

as you can see here, it’s almost completely frictionless Even more slippery than ice Which means it should be perfect for skating And while surfing, skating, and bowling it was ultimately so hard for us to keep our footing There’s like no way to stop We decided to call in a Pro This is Anna And she’s a ten-year-old skateboard competition winning legend Are you doing a shove?

I was doing a kickflip, obviously.

Oh.

*snort giggle* And she absolutely dominated the BB Floor Hey!

But, could she pull off the impossible jump?

Ow... I think I broke all my bones Now, what makes Anna so great Oopsie is that she’s incredibly tenacious Can I still land it or no?

And she never gives up so before she take her final shot at nailing this trick We need to discuss the science behind this room-temperature ice rink Because intuitively, it should make sense why this blue ocean is so frictionless.

Because any given BB rolls smoothly on the ground and your foot rolls smoothly on top of the BB, so when you have hundreds of these underneath you it's like you have hundreds of perfect wheels to slide you in any direction.

And what's really cool is if you take the floor and replace it with metal, and then take your foot and also replace it with metal, then you just connect the top surface to itself like this, and the bottom surface to itself like this.

Well, now they'll still slide relative to each other.

Just as good as my foot does with the floor.

And this is exactly how ball bearings work.

And besides being just in your fidget spinner, ball bearings are everywhere.

They're in your bike, skateboard and roller blade wheels where the wheels connect with the axles.

You’ll also find them in aircraft engines washing machines and a bunch of other tools pretty much anything you see that rotates where smooth low-friction is required will have ball bearings that work just like this floor.

Another really cool thing we discovered is that when you interact with all the BBs, they almost behave like water would, even though they're totally dry.

And this actually makes sense.

And it's sort of what you would expect, because when computers have to simulate water in order to predict how the water would interact, they break it down into particles like this.

And although it's not a perfect 1 to 1 match for a bunch of actual physical BBs, they are governed by many of the same forces, so they end up looking very similar.

Now back to Anna, who didn’t dissapoint WheeeEEEeeeeEEEeeee Now that we’d all survived number 8 I’m dead Coming in at number seven are these chairs.

But what makes them really cool is they're made from one single sheet of continuous plywood.

So you start with the sheet of plywood like this.

then you give it a paint job.

Then you place it on a CNC router machine, and you have it cut into this very specific pattern.

And after that, you just take out the middle part and then fold it into an actual functional chair.

Now, it's weird to think of wood as foldable and bendy, but this is another example of a compliant mechanism, which as you recall from my world's smallest Nerf gun video, is when you could take advantage of the fact that even solid materials can flex and bend if you give them the right shape.

And just like with the world's smallest Nerf gun, this chair was designed in the BYU Compliant Mechanisms Lab.

and there's a 3D printable file in the video description if you want to assemble your own mini single part foldable chair.

Now, number six is your key to being the coolest person at your end of summer block party.

Because right here, you've got a vinyl tube that's ready to spit out water and it's connected to a subwoofer speaker.

So now if you turn on the subwoofer at 30Hz, which means it's vibrating up and down 30 times per second, it wiggles the tube up and down at 30 times per second.

But then if you set your phone camera to record at 30 frames per second, it makes the motion virtually undetectable So when you squirt some water through the tube and start the speaker your camera is only taking pictures when the wave is at this exact position every 1/30 of a second.

So when you play it back, it looks like it's a frozen wave of water.

Now what's cool is if you change the subwoofer frequency to say, 31Hz or 31 times per second, now every 1/30 of a second, the picture of the water wave is just a little further forward, so it makes it look like the wave of water is slowly traveling forward.

and of course reducing the frequency and of course reducing the frequency has the opposite effect.

And if you're smart about it, this can make you look like an absolute wizard.

this can make you look like an absolute wizard.

But if you can use one speaker to make the wave go up and down.

Theoretically, if you had a second speaker and you made the wave go side to side, and you made the wave go side to side, and you made the wave go side to side, the combination should give you a spiral.

And sure enough, it actually does.

Now all that's left is to just play a sick beat to celebrate the W.

Now, this is sort of an extensive setup, but what's really cool is you can make a very simple version of this yourself.

And all you'll need is a hose, some tape and a cordless drill.

and a bit Start by folding the tape into a flag to provide an offset weight then secure the hose to the bottom of the cordless drill and then turn them both on you’ll find the natural vibrations of the spinning drill cause the hose tip to rotate in a circle near the magical 30 times per second rate, and then changing the speed of the drill slightly with the trigger will cause the wave to change directions.

Honestly, how cool is this?

Now, a lot of people confuse what you're seeing here with a really cool phenomenon called laminar flow, but they're different.

Because this is laminar flow.

it’s when the layers of a fluid interact by sliding over one another in a predictable pattern instead of going turbulent and unpredictable.

The big difference is what you see, what the speaker is only impressive through the camera feed, because the frame rate matches with the wiggle rate, but with laminar flow it looks cool even real-time with your own eyes.

And once again, the good news is you can make a simple version of this yourself too.

If you just get a balloon like this, fill it with water, If you just get a balloon like this, fill it with water, If you just get a balloon like this, fill it with water, tape a tic-tac-toe square like this and then give it a good cut right in the middle and as you can see here even with these really simple materials it looks like total magic The next two inventions are pretty quick and simple.

Before we make it to our final three absolute bangers starting first at number five with this heavily modified Roomba.

Because every single month we place a platinum ticket inside one CrunchLabs Build Box.

And if yours has it. I got it!

You're coming out here to CrunchLabs in person.

And while you're here, it's very likely we'll have a very fun, epic Nerf gun battle.

What's not so fun, however, is the epic cleanup required afterwards.

But why clean up a mess when you could just invent a robot to do it for you?

So by taking the front of one of these acorn picker uppers and 3D printing an attachment to secure it to a Roomba, things get much, much easier.

So with only the occasional empty of the chamber, I could spend my time working on coming up with other ideas Ideas like number 4, because over the years myself and CrunchLabs have received a few awards, and it feels too weird to put them on display in the front lobby in a trophy case.

But it also seems disrespectful just to leave them in a dusty bin.

So the middle ground is if you stand right here and pull this unmarked handle it uses a 6 to 1 mechanical advantage pully system to rotate this mirror 45 degrees into place.

And now, if you just so happen to look up standing only in this exact spot, you can admire the hardware.

And that brings us to the final three, starting with Simon, one of the most beloved games of my childhood.

Basically, it lights up one of these pads and then you just have to repeat it back by pressing the same pad.

And that's easy enough, but each time it adds another pad to the pattern, which just not so bad at first, but then it starts to add more and more and get faster and faster.

DANG IT!

just as frustrating as I remember.

I think the furthest I ever me as a kid was like level 13.

But lucky for me, I'm now an engineer, which means I have a very particular set of skills.

Skills I have acquired over a very long career, skills that make me a nightmare for games like these.

So if we place Simon right here and then take some inspiration from this incredible cockroach trap, we can add four posts around the perimeter, each with their own drumstick, rubber hand and high-torque servo motor.

So these can be our pad smashers, but now they need to know which pads to smash.

For that, we've just got a simple webcam here that runs a Python script from a Raspberry Pi, and it ignores everything in the camera field of view except for these four small rectangular portions where the bulbs are.

And so when the color suddenly intensifies in any one of those rectangles, you know, that's the pad that needs to be hit.

So once you store those pad hits in memory to be played back the game becomes really easy Like, violently easy Here we go.

So now, all we had to do Good is get through all 32 levels of Simon level three bring your A-Game and while 32 seems like a random number of levels, there’s actually a reason for it It turns out, in 1978 when this game was made, bits were expensive.

and the number 32 is the exact highest number you can count to in Binary if you only have 5 bits to spare after 5 minutes we’re half way there, so while my pad smashing robot avenges all my childhood losses I just want to point out, just like all the things you've seen in this video so far, my favorite thing about thinking like an engineer is you can basically make whatever you can dream up.

And if you want to start developing this skill yourself, CrunchLabs has you covered because for kids we've got Build Box and then for teens and adults, we've got Hack Pack.

In both cases, they get delivered right to your door where we build them together and learn all the really cool physics that make them work.

Plus all the fundamental tools you need in your toolkit to start creating your own projects and inventions.

Oh baby! That’s level 27 - five more to go.

So this holiday season if you or someone you love wants to take the first step of unlocking the really fun and rewarding hobby of making stuff CrunchLabs! YEAH!

Just scan this QR code or head to Crunchlabs.com FINAL LEVEL LET’S GO!

feels like a moment...

And so after 10 minutes, with a bit of a robotic assist I’m happy to say YEAHH!

I finally beat this dumb game We did it!!

Gimme some blue red green yellow On to number 2!

And that's this little guy.

His name is Rocky, and he's a robot who's really, really good at only one thing.

Dang it.

But before I show you just how good if you don't happen to have a rock paper scissors robot yourself, you should know there's a trick you can use playing against other humans to win 75% of the time, because a few years back, researchers studied 54,000 games of rock, paper, scissors and discovered a pattern.

If your opponent wins, they're slightly more likely to stay with their previous choice, and if they lose, they’re slightly more likely to shift their choice to the next in line of rock, paper, scissors.

So here's all you need to remember.

If you win, go to the next one in the line in the order of Rock, Paper, scissors..

So if you beat them with rock play paper next.

And if you beat them with paper, play scissors next And then if you lose, go backwards on the line of Rock, Paper, Scissors.

So if lose with scissors, play paper, if you lose with paper, play Rock Move forward if you win, move backward if you lose Now of course, that doesn't mean you'll win every game, but it does increase your odds by 10% for any given game.

So if you just play best of 20, those odds add up and you'll win the series 75% of the time.

And as a man of science, I actually tested this myself and it totally worked.

Again, I didn't win every game, but it just gave me a slight edge, which is all it took.

Now, as for beating Rocky.

Sadly, regardless of your strategy, your chances are much, much lower.

ROCKY!

as in 0%.

And that's because Rocky not only tracks the position of my hands, so he matches my movements up and down, but he checks the position of my fingers 100 times per second using an IR hand motion detector and a mini computer to determine what I'm throwing.

And then once the computer knows it, tells the correct servo motors in Rocky's 3D printed hand to actuate to throw the winning shape.

Now, as you can see, whether I go slow Or I go fast.

He somehow always wins.

The first person to beat him fair and square gets the $10,000 cash briefcase.

But honestly, I think your chances are still better at just hitting the bullseye with the American Gladiators tennis ball cannon the bullseye with the American Gladiators tennis ball cannon And finally, we made it to the number one coolest thing we built the CrunchLabs over the past year.

The infinite slinky staircase.

Like most good inventions, the slinky was invented by accident in 1943 by a naval engineer who inadvertently knocked a stabilizing spring off the shelf and noticed how it walked down instead of falling straight off.

So he and his wife decided to make a toy out of it, call it a slinky.

And now, 80 years later, over 300 million have been sold.

And as a kid, I loved Slinkys, especially trying to see how many stairs in a row I could get it to climb down with my record sadly being only 7 or 8.

So naturally, now that I'm an engineer, it was time to avenge this childhood frustration.

The first thought I had was using a treadmill tilted at just the right angle.

The problem with that was there was very little repeatability, because the landing surface was inclined like a ramp unlike actual stairs So to solve that issue, we tried an actual escalator and that worked a little better.

But the distance between the steps wasn't ideal and the speed was a little too slow.

And that's when we just decided to make our own prototype of an escalator.

I could turn with a hand-crank.

Fun fact this is how escalators actually work.

You don't normally think about it, but these stairs are making a round trip, so they're coming up below you like this upside down.

As you make your way down.

And that prototype worked well because we got the stair space dialed in but we were having trouble keeping the slinky aligned which is where these 3D printed self-centering cones came in handy because if we put one on each stair step, the slinky would self-align and then be in the perfect position to fall to the next step.

and then be in the perfect position to fall to the next step.

Finally we got rid of the hand crank by adding a motor with a speed controller that varies the voltage, so we could get the timing dialed in just right, and that was almost perfect.

But it turns out the speed of the slinky sort of varies slightly over time.

So now that the dutiful prototype had served its purpose, we made a final version that looked beautiful we made a final version that looked beautiful and had a time of flight proximity sensor on the front, so it would run a closed feedback loop to change the speed of the motor to ensure the slinky was always right in the middle of the staircase.

And when you do all that, you get this.

But before the official demonstration, you should know what I think is the coolest thing about a slinky.

Because if you let one hang down like this and then let it go, the bottom stays perfectly still in one spot because it's balanced between gravity and the tension force pulling it up.

And that tension force pulling up stays unchanged until the wave finally propagates down at which point it's like, oh, I guess I'm supposed to fall now.

And so without further ado, here it is.

And so without further ado, here it is.

What's really cool is once it's running, you can push either of these two buttons to temporarily slow down, or speed up the staircase.

After which the sensor takes back over, to adjust itself back to the middle Now, given that my childhood record was eight steps I'm just going to leave this running to see how much I can beat that by.

All right.

This is now been running just over 48 hours, which means that slinky has traveled just over 208,000 stairs, which is just over 29,000 times more stairs than I ever got as a kid.

So I'm calling that a W So I'm calling that a W in my ongoing quest to be the favorite uncle I’ve tried quite a few things over the years Who’s your favorite uncle?

SAY MY NAME But now I finally discovered a much easier way So you too can be the favorite uncle Or Aunt Or even parent By simply gifting a young person in your life a CrunchLabs Build Box subscription for the holidays So it gets delivered right to their doorstep And then we build a really fun toy together It’s basically like unlocking your own personal Mark Rober video every month Where you learn a new engineering principal That will have you not just building like an engineer But more importantly Thinking like an engineer So you’re developing resilience and problem solving skills Which means some day you too could be building robots To avenge your childhood frustrations Not only that, but each month your box has the chance to contain the platinum ticket And if you get it?

Well then you’re coming out to CrunchLabs to build with me and my team for a day so if you wanna grow your brain in really fun ways with me just head to CrunchLabs.com or use the link in the description Where we’re giving away 2 months free As a holiday special Thanks for watching