【臺(tái)詞】Do You Know S1-12 Helicopter Rotor and Tricycle

【臺(tái)詞】Do You Know S1-12 Helicopter Rotor and Tricycle

Do You Know S1-12a Helicopter Rotor1人有 · 書評(píng)1 Do You Know S1-12a Helicopter Rotor

Do You Know S1-12b Tricycle1人有 · 書評(píng)1 Do You Know S1-12b Tricycle

Hello, I'm Maddie and today I've

come to see a very exciting vehicle.

See if you can guess what it is.

It carries people in it,

it doesn't have wings and it

has a big piece of metal on top that

spins round and round.

Can you guess what it is?

OK, I'll give you one more clue.

It sounds like this.

ROTOR BLADES WHIR

That's right, it's a helicopter.

Noisy, isn't it?

Helicopters are amazing to watch.

Have you ever seen one

flying in the sky?

You often hear them before

you see them.

This bit of the helicopter is called

a landing skid,

and there are two of them.

They're the helicopter's feet.

This bit at the front is where the

pilot sits to fly the helicopter.

It's called the cockpit.

And then this long part at the back

of the helicopter is called

the tail boom and at the end of

it is the tail rotor.

This spins round and round when

the helicopter flies,

just like the big rotor at the top.

This big rotor is really important

because it helps make the

helicopter fly.

But do you know how

a helicopter rotor works?

Let's find out.

To get a closer look at the rotor at

the top of the helicopter,

I'm going to use my special camera.

So here we go,

let's move it right

to the top.

This part in the middle,

that is called the rotor disc, and

then these two long metal things

coming out of the sides are called

the rotor blades.

Let's move along.

They are so long, aren't they?

But can you see that one edge of the

rotor blade

is slightly thinner than the other?

I think it looks a bit like a fish,

don't you?

But let's move back to the middle

now to look at the rotor disc.

Oh, the rotor disc

has lots of metal parts, doesn't it?

So to understand how it really

works

we need to look in more detail.

On top of the helicopter is

the rotor.

The long blades meet in the centre

and are attached to

a metal pole called the rotor mast.

When the helicopter engine starts,

the rotor mast starts to spin

round and round,

making the blades spin too.

Another circle of metal called the

swash plate also spins round.

It's attached to the blades by two

metal poles called control rods.

These rods are connected to controls

inside the helicopter cockpit.

To make the helicopter take off,

the pilot moves a lever upwards.

This moves the control rods in the

rotor, which makes the blades move.

When the blades are in the right

position, they push the

air downwards, and this allows the

helicopter to lift up into the air.

The pilot pushes another lever to

make the rotor tilt

up at the back, and this makes the

helicopter go forwards.

To go backwards, the pilot pulls the

lever back,

which tips the rotor up at the

front,

so the helicopter goes

backwards.

Clever, isn't it?

Shall we see the rotor working on

this helicopter?

But, before we fly, the pilot and I

need to put our headsets on.

And I'm going to be

talking through this.

It's called a microphone, and it

might make my voice sound funny.

I think we're ready to go.

ENGINE REVS UP

Watch the blades start to turn.

Slowly at first

and then very, very fast.

We're just warming the

engine up now but

when we're ready, Tom's going to

pull the lever,

which will move the blades into the

right position,

and when we're

catching the air, we'll take off.

RADIO CHATTERS

Here we go.

Wow!

You can see Tom the pilot now is

using the cyclic lever

to tilt the rotor up at the back,

and this makes the helicopter go

forwards.

Wow, we're so high!

The view is beautiful from up here.

Now we're heading to a town.

The houses look tiny.

They look like doll's houses.

We're coming in to land now.

And there we go, we're back at base.

What was your favourite bit about

finding out

how helicopter rotors work?

Do you remember the name of the long

pieces of metal that turn

to make the helicopter fly?

That's right,

they're called the rotor blades.

Did you hear the sound the

helicopter made

when I was

standing near it?

ROTOR BLADES WHIR

Noisy, isn't it?

And did you see the way the

helicopter travelled forwards

when the pilot moved the lever

inside the cockpit?

So, now you know how the

rotor on top of a helicopter works

and how it makes a helicopter fly.

Helicopters are exciting vehicles,

aren't they?

They're fun to watch in the air,

but not many people travel

around in helicopters.

But there are lots of other

vehicles, aren't there?

And you might have had

a go on some of them.

You might have been on a bicycle

or a scooter, or maybe a tricycle.

Have you ever ridden a tricycle?

Tricycles are great fun.

They're a bit like bicycles,

except they have three wheels

instead of two,

and that helps you to balance.

Off I go.

But do you know how

a tricycle is made?

Let's find out.

To see how a tricycle is made,

I've come here.

Inside that workshop they make

lots of tricycles,

some for grown-ups and some

for children.

Let's go see how one's made.

To make a tricycle, first the

mechanics open up this box,

and can you believe that all the

parts needed

to build one tricycle fit inside?

Over to you, Scott.

There are 25 parts to this tricycle

and they're all different

shapes and sizes.

Can you guess what some of them

are going to be?

This is one of the pedals,

the part you push with your feet

to turn the wheels.

And what about this?

Well, these are the handlebars,

the bit you hold with your hands.

And what about this one?

This is called the saddle,

and it's the bit you sit on.

Now all the pieces are out

of the box,

Scott can start making the tricycle.

First he puts two big red pieces of

metal on to a stand.

The metal pieces are called

the frame,

and he attaches them together.

Scott hangs them up on the stand

because it makes it easier

to attach all the other pieces.

It's like it's floating in mid-air.

On goes the saddle.

Next, Scott is going to put

the chain on.

The chain is a big loop of metal

links that help the pedals

turn the wheels,

but this can be fiddly,

so I'm going to put

a special camera on Scott's head.

OK.

By attaching the camera to Scott's

head, we're going to be able

to see what he sees when he's

putting the bike chain on.

Does that feel comfortable?

Yep, it's fine. OK, on you go.

Now we're getting a really clear

view of everything Scott is seeing.

First, he's picked up the chain and

looped it around

that metal circle.

It's called the cog.

Scott joins the chain together

using a chain tool.

He adjusts the frame of the bike

using a spanner

to make sure the chain is tight.

Then he tests it to make sure the

chain fits perfectly

and won't fall off.

Now the chain is fixed in place,

the next part of the tricycle to go

on are these - they're pedals.

You push the pedals with your feet

to turn the chain,

which moves the tricycle.

There are still quite

a few pieces left, aren't there?

Well, now we need

the front mudguard.

A back mudguard.

The other back mudguard.

Back basket.

And the front basket.

Now it's time for the front wheel,

and it's attached to the frame

with these big bolts.

TING TING!

Nyoooooom!

Well, you can't have a tricycle

without handlebars,

and these ones are great because

they've got a bell on them.

Listen to this sound.

TING TING!

Let's hear it again.

TING TING!

Isn't that fun?

Here you go, Scott.

To attach the handlebars,

Scott is using a special tool.

It's called an Allen key,

and you might have seen

a grown-up using one at home.

It has a shape at the end of it.

Do you know what this is?

This shape is a hexagon and it

has six sides.

This fits into a bolt at the top of

the handlebars and,

as Scott twists it, it makes sure

they're on really tight.

Next, Scott attaches the

brakes and cables.

Brakes are really important because

we need them to stop the tricycle.

This bit here is called the

brake lever,

and when we squeeze it this cable

pulls these bits of rubber

on to the wheel, which slows it down

and brings it to a stop, like this.

Having started with all those

pieces, we've got just two left,

the back wheels.

The back wheels are attached to the

tricycle and it's ready to go.

Ha, and here is the finished

tricycle.

What do you think?

It looks fantastic, doesn't it?

But sometimes the mechanics here add

a few extra bits

so that children with disabilities

can use the tricycles too.

BELLS RING

These pedals have extra straps to

help keep your feet in the

right place, and this saddle

has a comfy backrest and a seatbelt.

This is great for someone who needs

a bit of extra help sitting up.

And this is a handle so that

a grown-up

can help push somebody along.

What was your favourite bit about

seeing how a tricycle was made?

Do you remember what you call the

special tool Scott used

to tighten the bolts on the

handlebars?

That's right, it's an Allen key.

Did you hear the sound the bell

made when I pressed it?

TING TING!

Isn't that fun?

And did you see all the different

parts of the tricycle

when they were unpacked from the

big box?

So the next time you see a tricycle,

or get to ride on one yourself,

you know just how it's made.

And now you know how

a helicopter rotor works,

just like on this one here.

I'll see you next time.

BYE!