Hello and welcome to today's design and technology lesson.

My name's Mrs. Fletcher and I'm here to help and guide you through your learning today.

Today's lesson is called Assemble an electric vehicle and it's part of the Pulley and gears: electric vehicles unit.

In this lesson we'll be looking at the different components that we can start to add onto our vehicle chassis in order to make it run.

We'll be looking at why we need those components and how to attach them correctly.

So let's have a look at what we'll be learning about today.

The outcome of today's lesson is I can add mechanical and electrical components to a vehicle, and in this lesson we'll learn what those mechanical and electrical components are, and by the end of the lesson we'll be able to describe the difference between an electrical and mechanical component and explain the job they do on our prototype electrical vehicle.

There are some keywords that we're going to see in today's lesson, so let's have a look at those together before we get started.

So first of all, we've got that word mechanical, and that's a keyword in today's lesson because that's talking about a system or machine that uses moving parts, and those are some of the things we're going to be adding onto our chassis today.

Then we've got the word electrical, and that's talking about the components that we're going to add today that are powered by an electrical current.

And then we've got the word components itself, and that's talking about those different individual parts of a system or machine.

So mechanical components and electrical components are the different parts we'll be adding to our vehicle today.

Today's lesson is going to be broken down into two parts.

First of all, we're going to be looking at the mechanical components, what they are and how they will fit onto our vehicle, and then we'll be looking at the electrical components and how they are different to the mechanical components and how we can fit those to our vehicle as well.

So let's get started by looking at the mechanical components.

To make a prototype electric vehicle move, we need to add some components to the chassis.

So it's not going to move by itself.

The vehicle will have some mechanical components and some electrical components in order to make it work.

You might be wondering, like Aisha here, what's the difference between a mechanical and electrical component in an electrical vehicle? Well, the mechanical components are the moving parts, and those are things like the wheels, the axles, the pulleys, and the bands that might be included in this vehicle.

So they don't power themselves, but they move.

And then we've got the electrical components that use electricity to move those mechanical parts.

So this is where the power comes from to move those mechanical parts, and that will include things like the cells or batteries, wires, motors, and switches, and those are all part of an electrical circuit which will power the vehicle.

The mechanical components need to be positioned correctly and fitted into place on the chassis.

So we can see here the mechanical components that we're going to be adding onto our chassis.

We've got wheels which are connected to axles, and then we've got a pulley and a band which is also connected to one of the axles as well, and they're going to be the moving parts of our vehicle.

A quick check then.

Which of these is a mechanical component? Is it the cell, the wheel and axle, or the motor? Pause the video and have a think.

Welcome back.

What did you think? Well done if you said it was the wheel and axle.

So those mechanical components don't power themselves, but they are moving parts.

Well done if you got that right.

So these are the resources that we're going to need to add those mechanical components to our vehicle chassis.

So you should already have a pre-built chassis including an axle holder that's already part of that chassis as well.

Then you're going to need four wheels.

Now, they could be wooden or cardboard wheels, but they need to be 50-millimeter diameter.

We're going to need a piece of wooden dowel which is 300 millimetres long, and it's best to use five-millimeter dowel for this task.

It fits much more securely into the holes of the wheels.

If you use a thinner dowel, you might need to use glue to secure it to the wheels.

Then you're going to need one grooved pulley wheel.

So again, this can be wooden, plastic, or cardboard.

And then you're going to need an assortment of elastic bands, because you'll need to find one that fits correctly to your pulley system when you attach it to your vehicle chassis.

So those are the things you're going to need to get together for this part of the lesson.

Now, these resources are what you will need if you have a standard rectangular shaped chassis, prebuilt chassis.

If you've got an alternative shape, then you may need to adjust the size of some of these components in order to fit your vehicle.

But you can still follow the steps.

You may just need to adjust some of the sizes.

The size of the pulley wheel that we use will affect the speed of the vehicle.

So if you've got a choice of different sizes, then you need to think about which one you're going to use.

The larger the pulley wheel, the longer it takes to rotate, which means it will slow down the speed of the vehicle.

If we have a smaller pulley wheel, it will rotate much quicker.

That will increase the speed of the vehicle.

So if you're thinking about how quickly or slowly you want your vehicle to move, then the size of the pulley wheel is going to be the thing you need to think about in order to change that speed.

Using a safe and accurate sawing technique, we can cut the 300-millimeter piece of dowel in half to make our two axles, and both axles will be 150 millimetres long.

If you haven't got the standard rectangular chassis, then you may need to adjust that to make sure these axles fit on your chassis as well.

Now, when we're sawing dowel sections, it can be a little bit trickier than when we're sawing flat or square pieces of wood, but if we follow a few steps it will make it a little bit easier.

So it can be a good idea to use a separate piece of wood, an offcut piece of wood to hold your dowel in place on the bench, as well as using a clamp or a vice as well.

We want to reduce the movement.

Because it's a rounded piece of wood, it can move quite easily.

So we want to make sure it's secured into place as well as we can before we start sawing.

And then we need to make a groove in the dowel before we start sawing it in half.

And to do this, you place the blade on the dowel, pull it back towards you, and then lift and reset it back on in the same place, pull it back towards you again, and repeat that a few times just to make a few little cuts in the dowel.

And this will give you a secure place to put your saw to start sawing.

And as Sofia is reminding us here, "Holding and cutting dowel can be tricky to do without splintering the wood." So that's the danger when we're cutting dowel, is that we'll splinter that wood.

Using those small cuts first makes it easier to cut in half.

So once you've done those small cuts, you'll be able to use a slow sawing motion to get through the rest of that piece of dowel.

Now, these are the steps we're going to need to follow to assemble those mechanical components, those moving parts onto our vehicle chassis.

So step number one, first of all, we're going to insert those axles that we've cut from our wooden dowel through the holes that we've made in our chassis.

So those are our axle holders that you should already have in your chassis, and you're going to just insert them both to check the position and check the length.

If they're not long enough, then you may need to cut some longer pieces.

If they're a bit too long, which will mean your wheels are too far away from your chassis, then you may need to trim some off to make them a little bit smaller.

So they should look a little bit like you can see in the image there, where they do come out from the side of the chassis, but they fit comfortably without too much excess or being too tight.

Once you've done that, you can attach the two wheels onto the axle that will not hold the pulley.

So this is the one that has not got a hole in the chassis underneath it.

So you can see from the image there, I've got the axle above the hole and I've got an axle with wheels on that's not got a hole underneath it.

So just put the wheels on that side for now, 'cause we're going to need access to that hole on the opposite side.

So you can remove the axle from the side that has the hole in the chassis and you can add the pulley wheel, that grooved wheel that we've got for our pulley, onto that axle.

And it should be in the centre.

It's going to need to be above that hole in the chassis.

Once you've done that, you can add an elastic band onto that axle.

It's going to eventually wrap around the pulley wheel and the motor.

At the moment, it's not got anything to attach to, so you're just putting it in position.

So just make sure it's looped over your axle so that when you put the axle in place, the elastic band is secure.

And then you can insert the axle back into place.

So you have to do one side first and then the opposite side because you've got that wheel on the axle now.

So you can't just push it through from one side.

But position that axle back in place.

And then step five, you need to turn the vehicle over and add the wheels to that second axle to keep it into place.

And you should be able to see once you've turned it over the pulley wheel and the elastic band through that gap in the chassis.

If you can't see it, it's not in the right place.

You may need to adjust it a little bit so that you can see it and it can move in that space.

Quick check then before we move on.

What name is given to the frame of the vehicle that we're attaching these components to? Is it the motor, the chassis, the pulley, or the cell? Pause the video and have a think.

Welcome back.

What did you think? Well done if you said it's the chassis.

So we're attaching these components to the chassis, which is the frame of the vehicle.

Well done if you got that right.

So, that's your task for this first part of the lesson, is to assemble those mechanical components onto your prototype vehicle chassis.

So those are the components there.

They're the wheels, the axle, the pulley wheel, and the band, and those are the positions you need to put them in.

So we need both axles through the axle holders, we need the wheels on each end, and we need that pulley wheel and elastic band on the axle that is underneath the hole in your chassis.

Pause the video while you complete that task and then come back when you're done.

Welcome back.

How did you get on? Well, you have positioned and attached the mechanical components of your electric vehicle now, and it should look like this.

So your wheels and axles are in position and the pulley and the elastic band are visible through that gap in your chassis.

Make sure it looks like that and then you're ready to move on to the second part of the lesson.

In the second part of the lesson, we're going to be looking at the electrical components that we're going to add to our electric vehicle and how they will be positioned and how they will work alongside those mechanical components.

So our prototype electric vehicles are going to use a pulley system in order to move, and that pulley system is going to be powered by the electrical components that we're going to add in this part of the lesson, and those components are connected together in a circuit.

So we can see here the components that we're going to be adding.

We're going to be adding a battery pack, a motor, and a switch.

Those can be connected together.

We can see that, if we draw it as a circuit diagram here, what that looks like.

So we've got the switch symbol at the top, we've got that motor symbol on the left, and the battery pack and the cells at the bottom of that circuit.

So that's how they're going to be connected.

They need to be in that complete circuit in order for them to work.

Quick check before we move on then.

Which of these is an electrical component? Is it the wheel and axle, is it the motor, or is it the pulley? Which of those is an electrical component? Pause the video and have a think.

Welcome back.

What did you think? Well done if you said it was the motor.

So the electrical components are parts of an electrical circuit, which is going to power those mechanical parts that we've already added on.

Well done if you got that right.

So the motor that we're going to use needs to be positioned correctly so that it can be joined to that pulley by the elastic band that we've already connected to our axles.

So this is where you're going to do a little bit of tweaking, and you might need to adjust using different sizes of elastic band.

So there's your motor, there's the pulley that you can see through that gap in your chassis, and the band needs to be attached between them.

So it's a good idea to put the band on the pulley wheel and onto the motor, which should have a pulley attachment on it as well, put it onto it before you attach the motor to the chassis, and that way you can make sure you position the motor in a good place to allow the band to stretch between the two.

Now, the band needs to fit quite snugly between the pulley and the motor in order to work correctly, because if that band is too loose then it will fall off as soon as that wheel starts to rotate.

But if the band is too tight and it's too stretched between the pulley and the motor, then it will stop that wheel from turning because there'll be too much resistance from the band to allow it to move freely.

So you need to get a snug fit where it won't fall off but it's not too tight.

So that might need a bit of adjustment.

The motor can then be attached once you've found the perfect spot for it.

It can be attached either using some self-adhesive motor clips which clip the motor into place, or you can use a hot glue gun to glue it onto the chassis.

Now, you need to make sure you have an adult to help you with that if that's the option you're going to use.

Whichever option you use, you need to make sure that motor is securely in place so that the band stays in its position attached to that pulley wheel.

So there's the motor with the motor clip and the pulley attachment.

So this is a type of attachment you need to use to attach the band.

And that's the motor in position.

So you can see I've positioned my motor so that that band can stretch nice and tightly but not too tight onto that pulley wheel.

So that's what it should look like once you've positioned it.

If you haven't got any motor clips, you can attach the motor directly to the chassis.

Just make sure there's nothing stopping your pulley wheel and the attachment on the motor from moving.

Quick check then.

What would happen if the pulley band was too loose? Would it rotate the axle faster, would it stop the pulley wheel rotating, or would it fall off? Pause the video and have a think.

Welcome back.

What did you think? Well done if you said it would fall off, exactly.

If it's too loose, it can't grip onto the pulley wheel or the motor and it will fall off.

Well done if you got that right.

The battery pack is the next component that we need to attach into our circuit, and that should be positioned so that the wires can be connected to the motor.

So they are going to be connected eventually to the motor, so you need to make sure that it's positioned so that can happen.

So this is the battery pack with the wires already attached, and this is the type of battery pack you need to use.

It's got no cells in it at the moment because we don't want to power the system until we have connected the whole circuit.

The battery pack can be glued onto the chassis of your vehicle so that the wires will reach the motor.

We're not going to attach them yet, but we just need to make sure that those two wires will reach the motor so they can be attached later on.

Again, you can use double-sided tape, self-adhesive clips, or a hot glue gun.

Just make sure you have adult supervision for that.

Do not add the cells, remember, to your battery pack yet, 'cause we don't want that power yet.

So that leads us to the final task then.

You are going to position and attach those electrical components onto your prototype vehicle chassis so that they can be connected later on.

So you're going to position the motor so that that band fits tightly but not overstretched between the motor and the pulley wheel, and you're going to make sure that motor is attached securely to your chassis, and then you're going to position and attach an empty battery pack.

So make sure we've not got any cells in that battery pack, and we're not connecting the wires at this point.

We're just positioning it so that the two wires will reach the motor.

So that's the two steps we need to do in this task.

Pause the video while you complete that and come back when you're done.

Welcome back.

So, how did you get on? You should now have positioned the electrical components to your prototype electric vehicle chassis, and you should have the empty battery pack with the loose wires on one side and then you should have that motor clip and motor with the pulley attachment on positioned to attach the band to the pulley wheel.

So this is where you might have had to do a little bit of tweaking with the band to make sure you got the perfect fit between the pulley and the motor.

Well done if you've managed to complete that task.

You have your electrical and mechanical components in position.

So that is the end of today's lesson.

I've had fun looking at the different types of components, those mechanical and electrical components that we will need to power our prototype electric vehicles.

We've learnt that electric vehicles include both mechanical and electrical components.

We've learnt that those components needed to be added to the chassis securely using motor clips or glue as the best options.

We've learnt that those axles need to be connected to the pulleys to make sure that they will rotate once that pulley wheel is moving.

We've learnt that the larger pulley on the axle will slow the vehicle down.

So the size of that pulley wheel actually affects the vehicle's speed.

And we've learnt that the distance between the two pulleys, the one on the motor and the one on the axle, cannot be too loose or too tight with that band, otherwise it will not operate as intended.

I hope to see you again in the next stage of this unit where we can complete further steps on our electric vehicle.

Thank you for joining me today.

Goodbye.