>> ♪ We've got two days to get this straight ♪ We've got a challenge just won't wait ♪ Our eyes are on the prize ♪ An engineer just set the date ♪ We've got this client can't be late ♪ Oh, no it's go time ♪ Build it, test, fix it debug now and kick it ♪ Got to get it off the ground yeah ♪ Stick around and you'll see what teamwork's supposed to mean ♪ It's so key Design Squad ♪ Design Squad.

♪ >> Thanks.

>> Okay, guys, so we have a lot of things to fix.

>> There was a lot of, like, twisting, especially on this end, right, guys?

>> Yeah.

Yeah, we should add those ankle brace supports.

And also, we need to stiffen this up, because it wasn't giving any support.

>> We don't have that much time, so we kind of have to divide the tasks.

>> Yeah.

>> These poles right here are getting stuck in the ground, so Ill cut these off, trim these down over here.

>> Okay, let's do it.

>> So the other thing that we talked about was making the brakes, right?

>> Mm-hmm.

>> What if we make it out of the hollow half of a PVC tube?

Because it has the right angle.

So we push down the PVC, it would go like that.

>> Good idea.

>> I think we're doing okay.

We're going to be crunched for time at the end of the day today, but if we work hard, we'll be able to make it.

>> What do you think?

The smaller one?

>> I think once we cut it in half, we can sort of curve it to make it narrower.

>> That's how you do it!

>> Well, what did you think about this?

>> It's a perfect fit.

It's kind of amazing.

>> That's going to help a lot.

>> Once we get some more supports we'll be all right.

>> This works out really nicely, dude.

Really stiffens it up.

It's definitely a lot thicker.

Doesn't bend as much in the center.

After the tests, I lost a little confidence, because it was really wobbly.

But after putting on the reinforcements underneath, I think it helped a lot.

All right, so pretty good.

>> Yeah.

>> So other than the handle, what else do we have to do?

>> Weren't we going to do some kind of a footbrake?

What do you guys think?

>> I think that's good.

>> I'm going to go outside and look at the sled and see what we can come up with for the foot stop.

>> What I was thinking, I had this aluminum, and it bends upwards and attaches to this PVC pipe.

>> How are you going to bend it?

>> With my bare hands.

>> We have an ambitious one over here.

>> I'm going to try this.

So I have this piece of metal right here, and it attaches onto the steel plate I added.

And then underneath it goes the PVC.

When someone steps on it, it bends down and stops it, but it springs back up, because this aluminum is very springy.

I'm planning on riveting the PVC on it.

>> Using rivets is a good way to go, because rivets are strong, lightweight fasteners.

Annelise is using pop rivets.

Here's how they work.

A rivet has a shank and a mandril.

The rivet is inserted in a hole drilled through two materials.

A rivet gun pulls on the top of the mandril, expanding the shank.

As the shank expands, pulling on the mandril clamps the two materials tightly together.

The force from the gun then snaps off the mandril head at a premade break point.

It's called a pop rivet because of the sound the head makes when it snaps off.

>> How's the riveting going?

That looks nice-- very, very, nice.

>> Thanks, Juan.

>> All right, guys, I was just looking at the sled outside, and the foot stop is adjustable.

It goes down.

But once you're done using it, you take it back up into place.

So we have to have something that can facilitate that motion.

>> Green Team plans to slow down their dog sled with friction from a drag plate.

Friction is a force that resists motion between two surfaces-- in this case the ground and the plate.

The greater the force applied to the drag plate, the greater the friction between the plate and the ground.

And that decreases the forward motion of the sled.

Since the friction force is greater than the pulling force from the dogs, the sled stops.

And Wes is right-- they must also be able to lift the drag plate so they can decrease the amount of friction and accelerate the sled.

>> And I found these strips of metal right here.

What we can do is bolt one here and then connect it to a plate.

And this plate can be bungee corded right here, just so it'll pop back up once we're done using it.

>> Do you think this is sturdy enough, though, or... >> I think so, yeah.

>> While you do that I'm going to finish working on the steering system so that I can make it sturdy.

I'm going to use these plates, and I'm going to bolt them in here and here so that it cannot move forwards.

And we're just not going to tie the bolts all the way, so that it can move from one side to the other.

>> Okay.

>> That's really good.

>> Hey, guys, I want to build the stand, where you stand.

I want to make it out of this.

And Lindsey, you think you can weld it on?

>> Yeah, but I thought we were done.

>> So why don't you cut it, and then depending on the amount of time we have left, we can decide whether we're going to weld it or bolt it.

>> We have two hours.

>> I'm done.

These are the ski plates that the guy actually stands on.

So one of them will go here and one of them will go here, and he stands on them.

He stands on this.

>> Awesome.

That looks so good.

>> Yeah, yeah.

>> Do you want to work on this, then?

Sure.

This is going to be under.

Bolt, like, one here, one here.

>> Yep.

>> All right.

It's all you.

Zach was really moody this afternoon.

He was just kind of plowing through everything, just carelessly drilling.

I'm not really sure what his deal was, but me and Ana work together pretty well, and we'll kind of just let Zach go on and do his own thing while me and Ana work together on the main build.

I think that's good.

>> (laughing) >> Sorry.

You all right?

>> Yeah.

>> Zach, come on.

You can't be in a bad mood.

>> My bad.

>> I was screwing a bold on the handle, and I accidentally flipped it and hit him in the arm.

And I guess he got angry and just walked out.

>> The last thing he needed was for you to... seriously.

>> He's a big boy.

He can make his own decisions, choose how he acts.

>> What's good about this rope is it can pull, like, 20 Juans.

See?

Is this a good length, or should it be shorter?

>> I think it looks really good.

>> I'm still concerned about the stability.

Ana, can you hold the chassis down?

>> Yeah.

>> I think that's going to help a lot.

Yeah, good job.

>> Right now I am gathering stuff to make a drag plate.

>> That looks awesome.

>> So when it's being stepped on, the bungee is stretched.

>> Uh-huh.

>> But when it's not being stepped on, it'll be held up.

>> That's great.

Think you'll be able to do that in, like, an hour?

>> Yeah.

It should be a really quick thing.

>> All right.

>> Okay, guys, let's see if we can finish this quickly.

>> The brake's done.

>> Guys, this is awesome.

>> Okay, let's go test.

>> Brake.

>> Good, good.

>> Brake, brake.

Perfect.

>> We're going to Jamaica.

>> Jamaica, Jamaica!

>> We're done.

>> It looks good.

We're ready to go.

>> All right, guys, it's done.

>> Yeah, let's try it.

>> Put your tools down and your sandals on!

We're going to Jamaica!

>> Purple Team.

>> Nice job, guys.

This is really cool.

>> Jamaica, here we come.

>> I feel proud of what we made.

I really think it'll feel like you're going on snow, because we have the handlebars that go side to side, and the weight shifting that'll impact your turning.

So I feel like we really worekd hard to integrate the snow feeling into our sled.

>> I think we're going to do really well.

I mean, I saw the Purple Team's build, and it's really nice, but I think our main selling point is that it's light, and it'll be a lot easier to glide on the grass, and that's what they're looking for.

>> We're all at the airport.

>> Where are we going?

Where are we going?

>> Jamaica!

>> Jamaica!

>> We're so excited!

>> Land.

I see land.

>> Oh, look, it's the ocean!

>> Oh, goodness!

>> Look at the goats.

>> Oh, dude, it's a gaggle of goats.

>> Jamaica.

>> Look, there's a fruit stand right there.

>> Hey, guys, check out the market on your left.

>> Come on down!

>> Welcome to Jamaica, friends, and I hope you folks have a good time.

>> Oh, look.

>> That's really good.

>> I can hear the ocean.

Do you want to hear the ocean?

>> Bob Marley.

>> (with Jamican accent) How you doing, man?

>> Yeah.

>> I look cool, right?

>> You like it, you like it?

I can pull it off, dude.

I got the hips.

It's good, right?

It's good?

>> Here we are in Chukka Cove.

>> We're here!

>> I can't wait to meet the dogs.

>> Do you speak Jamaican dog?

>> (barks), mon.

>> That's Jamaican dog.

>> The dog yards are right over there in the corner.

>> Go, go, go!

>> I'm going, I'm going.

>> All right, guys, welcome to Chukka Cove.

We have a little bit of time to test the rigs before the clients get here with the dogs.

Green Team, are you guys ready?

>> Yeah.

>> Yeah, let's go.

>> I would say take it all the way up to the corner and make that right turn, and you probably want to test the brakes too just to make sure they're working okay.

Who's the dogs and who's the musher?

>> I'm the musher, these are my dogs.

>> Let's get ready to go.

>> In front?

>> Yeah, sure.

>> All right, you ready?

>> Yeah.

Don't go too fast.

>> You ready?

>> Don't go too fast?

Is this a race or is this a stroll?

>> We're just testing it, Nate.

Okay, fine.

All right, fine.

On your mark, get set, go!

>> Wait, don't go that fast!

Not so fast!

>> Brake, brake, brake.

Try to brake it.

Try to brake it.

>> Ready?

It works.

You're right, it was really good.

>> How was the stability?

>> It was stable, but it could be a little bit more stable.

But it wasn't bad.

>> Did it go pretty well?

>> Yeah.

>> Looked like you made the turn all right.

>> Yeah.

>> Brakes work?

>> Yes.

>> They do.

>> Sweet.

Ready for the dogs?

>> Yeah.

>> Purple Team's got to go first, though.

>> All right, let's go test.

>> Starting line is right here.

All right, who are the dogs and who's the musher?

>> Musher.

>> All right.

(dogs barking) >> Okay, I'm sorry, I'm sorry.

I won't do it again.

>> Are you ready?

>> On your mark, get set, go!

>> Whoa!

Whoa.

You pulled me off of it.

Juan!

>> Oh, whoa!

Why was it going by itself?

>> Too much power!

Let's try that again.

>> I know how to tuck and roll, but not crash a sled.

>> And Juan, try and keep the pulling level low.

If it's up here, it's going to pull it up too much.

All right, think like a dog, Juan, but don't bark like one.

Ready, set, go!

>> Beautiful!

>> Look at all the grass I dragged.

>> How'd it work?

>> It worked really well.

The handlebars steered, and this drag plate, like, braked a lot.

>> Good.

Sweet.

So you guys ready to test with the dogs?

>> Yeah.

>> Yeah, I think so.

>> Let's go meet the client.

>> Let's go.

>> Yeah, man.

>> She's so cute.

Isabella.

>> Hey, Jimmy.

You want a friend, too, huh?

>> Because we're using animals from the pound, it shows how much they care not just about winning, but about the sport itself and what it can stand for.

So I really...

I feel like they'd be really great people to meet, and I can't wait to show them what we've made.

>> He doesn't like to be on camera.

He's shy.

>> Hey, Design Squads, let's huddle up.

Design Squads, I'd like you to meet your client.

This is Rob and Newton.

>> Hey, guys.

>> Hi.

>> Hi, guys.

Have you meet all the dogs already?

>> Yeah.

>> Are you guys ready to test out the dog sleds?

>> Yeah.

>> Let's go do it.

This is going to be cool.

>> Yeah, we are.

>> All right, guys, here's the plan.

We're going to run each sled with a couple different combinations of dogs.

We'll try two dogs and three dogs just to see how they perform.

Green Team's up first, and I think Rob's going to drive.

>> Anything to prepare for?

The steering?

>> It's the opposite.

>> Okay.

>> Okay, and then braking, you just put your foot down, and it's like a bungee.

>> Okay.

Ready.

>> Ready?

>> Let's go, let's go.

>> Hup, hup, hup, hup, hup.

Go, hup!

Hup, hup, up.

Go, Chukka, let's go.

Hup, hup, hup, hup.

Let's go.

Hup, hup, hup, hup.

Let's go.

Whoa, whoa.

Whoa.

The line snapped under the wheel.

It feels good, but this could be, like, somewhere up here.

Because as soon as the line gets slack, it goes under the wheel, and it picked up the rope.

Move it from up the front axle, and maybe put it here.

>> The girl leads.

>> Let's go!

>> Go, go, go!

>> Yeah!

>> Hup, hup!

Let's go, Chukka, let's go!

>> Beautiful.

>> Hup, hup!

Hup, hup, hup!

Hup!

>> Go, go, go.

>> They're really fast.

>> Yeah, they are.

That's only three of them, too.

>> There they come.

All right.

Let's go check it out.

>> Yeah.

>> What'd you think of it?

>> Well, I think it went pretty good using more dogs, so it's less work on the guy.

It runs really smooth.

Because of the wheels, they are so small, so it needed a little bit more power to keep it going.

So it runs really smooth with more dogs.

The steering went really good, and the brake worked really good, only that it's in a really difficult position to reach to.

But other than that, it works really well when you get to reach it.

It is really light, but it's really good for the dog, because the lighter it is, the more easier it is for the dogs to pull.

So the lightness of it is perfect also.

So good job, Green Team.

>> Thanks.

>> Yeah!

>> Nice work, guys.

>> Green Team!

>> Sweet.

Well, Purple Team, you ready to run your dog sleds?

>> Yeah.

>> Let's go grab Newton and rig it up.

>> Hold on, hold on, hold on, hold on.

Okay, let's go!

Whoa, whoa, whoa, whoa!

Good dogs.

Good dogs.

Well, when I started out, and the front went up, it's like a wheelie.

It reminded me of the sled, because you have to step on the side to steer.

Okay, let's go.

Let's go, let's go.

>> Go, Newt!

>> Holy cow, look at him take the corner.

So fast.

>> They are hauling.

>> Go on, go on.

Go on, go on.

>> Here we go, come on!

>> Whoa, whoa, whoa.

Whoa, whoa.

>> How was it, Newton?

>> Yeah, man, it was fun in the sun.

The turns were cool.

It was easy, very easy, but the brakes is perfect.

It holds the dogs, and I think it's one of the best things on the rig here, man.

>> So does it feel like you're snow dog sledding?

>> The steering is like you're on snow.

>> Great.

>> Yeah.

It's really nice.

>> Well, Newton, let's go find Rob and talk about which one is actually better, and which team's going to win.

>> All right.

>> All right, yeah.

>> Nice work, guys.

>> Thanks, Newton.

>> Yeah, man.

>> Thank you.

>> So what did you guys think of the sleds?

Well, they were both two good sleds.

To me they both feel nice, comfortable.

>> Theirs did a lot better than I thought it would.

I thought the Green Team's was going to break as soon as he hooked it up.

It doesn't look that strong.

It's not built out of steel.

But it did pretty well.

>> I think ours did pretty well.

I mean... >> I think it was pretty light.

>> Yeah, it went fast.

He liked how it was lightweight and everything.

>> And it wasn't going to break because it had wooden dowels inside, even though Annelise said it would, but it wouldn't.

>> I don't know.

I think it can go either way.

It really could.

>> Yeah.

>> I was a little bit nervous, though, because theirs were a lot lighter, and it wouldn't take much force to pull.

>> Theirs is just made out of aluminum, but I don't even think it is that much lighter, because if you look at all the reinforcing they had to do, I mean, ours is the body and that's it.

Like, no extra weight, no superfluous pieces.

>> All that welding.

>> Yeah, it paid off in the end.

It's beautiful.

>> Whatever happens, you know, at least we had fun.

>> Yeah.

>> So overall these feel a little more like mushing on snow than the existing carts that you use for dry land?

As far as steering and... >> Yeah, it has a little feel to it as if you are riding in a sled, because you have to lean with the steering bar whenever you are turning, and that's what the sled is actually about.

For the Green Team, it was a little less stabilized than the Purple Team.

>> The Purple one, the brakes, I love the brake system.

>> Yeah.

>> I love how it steered.

>> Yeah.

>> Here they come.

>> Well, well, well.

>> All right, Design Squads, Newton and Rob have come to a decision about the dog sleds.

Newton, you want to start?

>> Well, I think the Green Team took the corner really good, light for the dogs.

I think you guys did a really good job.

>> Thanks.

Thank you.

>> The Purple Team sled, it was a little bit more sturdier, and it really feels as if it was... we were riding an actual sled in the snow.

So we would say Purple Team, you are the winner.

>> Yeah!

>> Congratulations.

Nice job, Purple Team.

100 points goes to each member.

Congratulations.

All right, Green Team, nice work.

I hope you've all had some fun and learned some stuff.

I think this has been really cool.

>> Yeah.

>> I'm so glad that the Purple Team won, because we had a really good teamwork going on.

We didn't think that we could do it, and it was one of, like, the proudest builds that I have, like, made so far.

Wes is already in the final anyway, so I don't feel so bad that he lost.

But it's also great to even, like, beat him.

>> Well, I mean, it was nice winning four in a row.

It's a humbling experience to finally lose one.

Jamaica's awesome.

I can't wait to jump off some cliffs right now.

>> Welcome to Jamaica, man!

A win for Purple Team means that Juan is tailing Wes by only 100 points.

>> Hey, Lindsey, there's so much more action on our Web site.

>> Yeah, behind-the-scenes stuff like our blogs.

>> Not to mention you can watch full episodes.

>> Play games and build cool projects.

>> Awesome.

Let's go to pbskidsgo.org.

>> Next time on Design Squad, the teams get grilled.

>> I want you to build a rotisserie.

>> Like a grandfather clock.

>> Some kind of water wheel.

>> That's some good pig.

Captioned by Media Access Group at WGBH