Lesson video

Hello, I'm Mrs. Enock and I'm delighted to be your design and technology teacher today, focusing on mechanisms: leavers and linkages.

Today's lesson is called developing an understanding of different mechanisms and how to make them.

Let's go and see exactly what we're learning about in today's lesson.

In this lesson, you are going to need a pencil, rubber, and ruler, some cardboard; now this can be recycled, for example old cereal boxes.

Scissors and split pins, and a piece of blue tack or plasticine, or something that you can push a pencil into without damaging your table.

Okay in today's lesson, we are going to be naming different mechanisms. We're going to explore exactly what levers are, and then we're going to experiment with different levers.

At the end we're going to recap on the different lever systems that we've explored today.

Okay keywords in today's lesson.

Our first word is mechanism.

If I say it, I'd like you to repeat.

So mech-an-ism.

Ready? Your go.

Mech-an-ism.

Excellent.

Mechanism is a device used to create movements in a product, and that's what we're working on.

We're working on making things move, our mechanisms. Our next word is lev-er.

Okay, can you say lever? Good, now a lever is a rigid bar which moves around a pivot.

We will be making our levers out of cardboard today.

Okay the next word is bridge.

My turn, bridge.

Your turn.

Super.

Bridge refers to the short strip of card, which is very important to use, as it keeps the lever and the linkage mechanism in place.

I'll be showing you how to make the bridge later in today's lesson.

Our next word is loose pivot.

Can you say that? Great, now our loose pivot, we're using a paper fastener for our pivot today, and a loose pivot is when the paper fastener joins the card strips together.

Okay our next keyword is fixed pivot.

Can you say that? Great, now fixed pivot, our pivot is our paper fastener, and a fixed pivot is when we use the paper fastener to join the card strips to the backing card.

We will explore this in today's lesson.

Okay let's move on to naming different mechanisms. So let's recap.

What exactly is a mechanism? Look at the pictures.

These are all examples of mechanisms. Let's pause and have a little think.

Okay here is the definition of mechanism.

A mechanism is where materials or components are connected to make movement.

And that's the key with mechanism, that it has to involve movement.

Can you remember mechanisms around your home or mechanisms in the world around you, for example the park or fair ground? Press pause and have a quick think.

Press resume once you are done.

Great.

Did you think about different mechanisms? Here's some examples of my mechanisms around my home.

I found scissors.

You can see the lever around the pivot.

I found a paper punch.

I found a ball clip.

And I also found a mechanism for when I pull my blinds up and down.

So just to recap, a mechanism is where materials or components are connected to make movement.

Point whether you think it's true or false.

That's right, it's true.

A mechanism is where materials or components are connected together to make that very important movement.

What is a mechanical system? A system is when more than one mechanism works together, just like this bicycle.

We will be using card and paper fasteners to create a system of levers and linkages.

Exploring levers.

Lever and linkage movements.

Have a look.

When we make our mechanisms, we produce different movements.

And there are four main movements.

I've got my little lollipop stick to help.

Linear is movement in a straight line, just one direction.

We also have, if you look at the pink box, a slider.

When the movement is backwards and forwards, but still in a straight line.

This can be up and down or backwards and forwards.

We also have the movement of rotary, which is when it goes round and round.

The final movement we have is oscillating.

When it goes back, the lever goes backwards and forwards in an arc.

Excellent.

Okay, let's recap.

Can you point to the symbol that means linear? Well done, linear is movement in a straight line.

Can you point to the movement slider? Brilliant, it's when it goes backwards and forwards, but still in a straight line.

Can you point to the symbol for rotary? Great, it's when it goes round and round.

And finally, do you remember the name for this symbol? Oscillating, it's when it goes backwards and forwards in an arc.

Okay, in today's lesson, we're going to be exploring different levers, and we're going to be using cardboard and split pins.

Now a lever moves around a pivot.

Can you see the pivot? That's right, it's the little orange circle.

We can move it in a curved motion and we can rotate.

So the lever, I'm going to use my finger as the pivot, and then the lever can move around or oscillating around the pivot.

Which of these shows the movement of a lever? That's right.

The lever is always around a pivot, and the pivot allows it to either rotate, or do an oscillating movement moving backwards and forwards in an arc.

Okay, to make our mechanisms, we have to use two different pivots.

Can you see the picture in the middle of a mechanism using cardboard? Great, now see the black circle in the middle.

That is a fixed pivot.

It means our paper fastener doesn't only go through the card strip, it also goes onto the backing card.

So it is fixed.

The lever and the pivot are attached to the back of the card.

That's what makes it fixed.

Okay, can you see the white circles? How many are there in the picture? That's right, there's two.

These are loose pivots.

That's because the paper fastener will join the card strips together, but they are not fixed to the back of the cardboard.

We'll be using this key when we make the mechanisms. So can you point to the fixed pivot in the picture? That's right, it's the black circle, showing the paper fastener is not only attached to the cardboard strip, it's attached to the back of the card as well.

And can you point to the loose pivot? Excellent, it's the white circles, when the cardboard is together and not fixed.

Here's an example of a mechanism.

This mechanism has got two pivots.

One is fixed to the back of the cardboard and one is loose.

Here's another mechanism.

Can you count how many strips of card have been used for the levers? I can see three.

I can see two orange levers and a blue lever.

How many fixed pivots can you see? That's right, one.

There's one fixed pivot right in the middle of the blue strip of card.

It's not only attached to the cardboard strip, it's attached to the back of the cardboard as well.

That's what makes it fixed.

And finally, how many loose pivots can you see? I see two.

I see two loose pivots where the paper fastener is only attached to the cardboard strips, not to the back of the main cardboard.

Here's another mechanism.

How many levers can you see? I can see three.

I see one long orange lever and two shorter blue levers.

How many fixed pivots do you see? I see two.

I see one attached onto the orange cardboard on the back of the cardboard.

I also see one that's just attached directly to the back of the cardboard.

And finally, how many loose pivots do you see? I see two, I see two loose pivots need to be used.

That's for paper fasteners altogether.

Here's another mechanism that shows different movement.

Oscillating, moves in the direction in an arc.

I see two loose pivots and I see two fixed pivots.

That's four split pins.

Okay, we're now going to experiment with levers, and it's really important to know that your mechanisms will not look exactly like my mechanisms, and that's more than okay.

That's awesome.

It means you're taking ownership on your mechanisms and you're experimenting with them for what makes the movement work well for you.

So before we start, we're just going to recap on what are we using as a lever in this project? Are we using plastic straw, piece of paper, cardboard strip, or paper fastener? Point to the one you think it is now.

We're going to be using cardboard strips as levers.

The cardboard strip is ideal.

It's strong enough for the good movement, but it can also be cut and measured into the needed shape.

Let's ask ourselves, what are we using as a pivot in this project? Plastic straw, piece of paper, cardboard strip, or paper fastener, also known as a split pin.

Point to the answer now.

Great, we're going to be using a paper fastener.

It's ideal to be used as a pivot, because a lever can rotate around the pivot, and we can put the split pin through the cardboard nice and easily.

Here's our quick safety warning.

In a moment you're going to be asked to use sharp scissors for the next activity.

Please go and ask an adult to be present before you start this activity.

Never use sharp scissors unsupervised.

Press pause, gather your equipment together, and then press resume, and we'll carry on with our learning.

Ready? Off you go.

Have you got everything ready? Excellent, let's get started.

For this activity, we're going to need a piece of cardboard, and we need to measure out the levers.

Now I have measured the levers to be three centimetres.

So I've used my ruler to make three centimetres, and then I can draw the line.

This way our lever will be in a straight line and will be the correct size we need.

I'm now going to measure a longer lever.

Again I'm going to make sure it is three centimetres wide.

So I've made a mark of three centimetres at the top and bottom of the cardboard.

And then when I draw the straight line, I can cut it out to have a long lever and a short lever, both three centimetres wide.

I've now cut out a smaller piece of card.

I've made it six centimetres long and three centimetres wide.

This is going to be the bridge.

And three centimetres wide.

I've glued the small piece of cardboard onto my backing cardboard.

Now as you can see, when I thread the slider through, it helps give it a controlled movement.

You have to make sure you don't put glue in the middle of the card.

Otherwise the lever won't be able to pass through.

Okay, now I've added the second lever, and I've made sure the corners merge together at 90 degrees.

Once I've done that, I can get a piece of blue tack or something soft.

This is so I can push my pencil through the cardboard without it damaging the table.

I've made sure the two levers are together in a corner.

And with a sharp pencil, you can push through both your levers and make a hole.

That will be where you are going to put your pivot.

I'm going to pop the split pin through the two holes.

And because we are not attaching it to the back of the cardboard, we've made a loose pivot.

Fantastic, two levers, one pivot.

Now we can slide the lever through the bridge, making sure that it's a loose pivot.

Now we need to make a fixed pivot.

So I've popped the blue tack underneath the back of the cardboard, making sure the cardboard lever is attached to the backing of the card, lining it up just ready.

And then we can make our hole using a sharp pencil or pencil crayon.

Make the hole.

There we go.

It's ready to put the split pin in to make our fixed pivot.

Pop it through, open the back of the split pin.

And there we have our mechanism.

As we move one lever backwards and forwards, did you see the oscillating movement? You can put any picture you like at the top of your lever.

And it makes a lovely oscillating movement, a backwards and forwards arc.

Isn't that great? Let's look at our next mechanism.

This is what we're going to make now.

We need three levers that are the same size and a piece of plasticine or blue tack for us to push them into.

As you can see, we've laid the levers how we're going to make them, making sure that they are 90-degree corners.

We can then put the lever onto our blue tack, and make a hole using the pencil.

We're going to put the split pin through the hole, opening the back to make our first loose pivot.

We're then going to place the two levers on top of each other, making sure it's an angle to make our second loose pivot.

Pop that split pin in.

There we have our three levers put together.

We are now going to attach the lever to the back of the cardboard, making a hole in the back.

Because we've attached the pivot through the back, it is a fixed pivot.

We've now attached the cardboard and I've made two bridges there.

Slide the levers in.

This will help give the controlled movement.

So we've got two loose pivots and one fixed pivot.

And when we move it back and forth, you can see movement is created.

As you can see, we've used the levers and the pivots to make a mechanism.

We can now bring that mechanism to life.

I've just decided to add a mouth 'cause I thought that movement reminded me of brushing teeth.

So we can attach just a little tooth brush there.

We need to make sure it's not attached to the bridge.

Otherwise there won't be the movement.

Show the mechanism have brushing with teeth.

Here's an example of the final mechanism.

There are two loose pivots and two fixed pivots.

When we move the lever, we're going to make an oscillating movement.

I need one long lever and two shorter levers that need to be measured out.

So the two shorter levers are the same.

We can then place the two shorter levers on top of the longer lever.

Adjust them to where you want them to be.

Remember it's okay to experiment.

We are now ready to make a hole into the two pieces of cardboard.

There's our hole where we will add our split pin, making a loose pivot.

We're going to add the split pin, making a loose pivot.

I open up the back.

There is the movement.

We then make a hole into the next two levers, so we can add our loose pivot.

Open up the split pins.

And there we go.

We've got two oscillating movements.

We've now got our backing of the cardboard, and we need to make a fixed pivot.

So aligning it, remember don't be afraid to experiment.

See what works.

So I'm making a hole between one of the shorter levers and the backing of the cardboard.

And that will make a fixed pivot.

Open it up.

Brilliant.

And we need to do the same with the other shorter lever.

We make a hole through the smaller lever onto the back of the cardboard to make our fixed pivot.

We open up the back of the split pin, and then we have a movement.

We move one lever backwards and forwards, and it causes the other two levers to make an oscillating movement.

Now you can bring those levers to life.

I have added sort of a unicorn horse, just attaching it to the middle, making sure that the added picture doesn't get in the way of the mechanisms. Just pop that on because we can experiment.

Remember, your mechanism does not have to look the same as this one.

We've got the movement like their legs.

Okay, now you've had chance to watch myself make different mechanisms. It's your turn.

In a moment, you're going to pause the video, and you're going to have a go at making your own mechanisms using one of the examples given.

You can make one or as many as you like.

You can add a moving picture to each moving part to explore the different ways it moves.

Remember your mechanism does not have to look exactly like mine.

It's important for you to explore and understand how to make different mechanisms and how they can move in different ways.

When you've finished, press resume, and we'll carry on learning together.

Ready? Off you go.

Okay, let's recap on different lever systems. What is the name of a movement which goes backwards and forwards? Is it slider or oscillating? Point to the correct answer now.

It's slider, slider is the movement that goes backwards and forwards.

What is the type of movement which goes in one direction? Is it linear or rotary? Point to the correct answer now.

It's linear, it goes in a straight line.

What is the type of movement which goes around in a circle? Is it slider or rotary? Point to the answer now.

It's rotary, rotary is the movement which goes around in a circle.

Have a look at the picture.

What type of movement is created by the outer part of the mechanism, by the output? Is it rotary or oscillating? Point to the answer now.

It's oscillating, the movement is going backwards and forwards in an arc.

What type of movement is created by the input of the mechanism? Do you think it's oscillating or slider? Point to your answer now? That's right, the input is a slider, the output is oscillating.

Wow! We learned a lot of things in today's lesson.

We named different mechanisms. We explored levers.

We experimented with levers.

And we recapped on different lever systems. I really enjoyed working with you today.

Thank you for your hard work.

Bye for now.