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

I'm Mrs. Fletcher, and I'm here today to help guide you through this lesson and help you with your learning.

Today's lesson is called Assemble cam mechanisms, and it's part of the Cams: automata unit.

It's a practical lesson, so we'll get to get hands-on with our learning today.

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

The outcome of today's lesson is, I can integrate a cam mechanism into an automaton.

So this is a practical lesson where we'll get to see how those cam mechanisms actually function inside a working product.

So we're going to be putting it inside an automaton in today's lesson.

There are some keywords that we will need in today's lesson that we're going to see quite often.

So let's have a look at those words for today.

We've got the word assemble, which means bringing together separate parts, putting them together to make one unit.

We've got the word components, which are the separate parts of a larger whole, the individual parts.

We've got the word drill bit, or the phrase drill bit, which is the cutting tool that's used to make holes, it is used in a drill.

And we've got the word chuck, which is a device for holding a tool in place, and we're going to see those in today's lesson.

Now, today's lesson's split into three different parts.

So we're going to be looking at preparing the components for our automaton and our cam mechanisms, but then we're going to move on to some safe drilling techniques, and then we're going to look at assembling that cam at the end of the lesson so we can see it functioning inside the product.

So let's get started with that first part of preparing the components.

In order to make an automaton, we need to insert a cam mechanism into a box frame.

So just like this, we've got a box frame and the cam mechanism sits inside it so it can operate the automaton figures, which would be on the top on the outside.

First, we need to prepare the components, that's the individual parts, of that cam mechanism.

So what is a component? Quick check.

Is it an automaton, is it a mechanism, or is it an individual part? Pause the video and have a think.

Well done if you said it is an individual part, exactly.

The components of our cam mechanism are the individual parts needed to make it work.

Using an accurate sawing technique, we can cut lengths of dowel to make some of those components.

So we need to make an axle, which is the longer part of the dowel.

We need to make a crank handle, which is a small section of dowel, and we need to make three followers.

So they need to be of equal size to make three equal followers on our cam mechanism.

Now, you might choose to do one or two followers instead.

If that's the case, then you adjust that to your project.

To create the correct movement of those followers to operate the animated element of our automaton, we'll need to make some cam discs, and the cam disc that you make in today's lesson should match the movement that you've planned in your design.

These should be made from thick corrugated card.

If you don't have a thick enough card, then making two and sticking them together, glueing them together, can do the job.

They need to be quite thick so that they make really good contact with the follower in the mechanism.

Different cams have different movements, remember, so you need to think about that when you are making your cam discs.

If you choose to make eccentric cams, then you're going to get that up and down, smooth up and down movement in your followers.

If you choose a snail cam, you're going to get that sudden drop, so your animated characters are going to rise and drop suddenly in your mechanism.

If you choose an ellipse cam, then you're going to get that more jagged movement.

And if you choose a pear cam, then you're going to get that small pause before it rises back up again.

So you should have considered these things in your design, but you can make those adjustments when you come to make it in this lesson.

Piercing a hole in the correct position for each cam is vital to allow it to make the correct movement.

So if you're thinking about an eccentric cam, then we've got that off-center hole.

If we are using a snail cam, then the hole needs to be in the centre of the circular part of the disc.

If you're choosing an ellipse cam, then it needs to be in the centre, and if you're choosing a pear cam, then it needs to be in the centre of the widest part of that cam disc.

Quick check then before we move on, which of these cams would you need to make a central hole in? Would it be A, the ellipse, B, the pear, or C, the eccentric? Pause the video and have a think.

Okay, what did you think? It is, of course, the ellipse that needs to be in the centre.

The pear would be in the bottom, and the eccentric would be off-center.

Well done.

So let's look specifically at how to saw dowel sections of wood.

So it's a little bit of a different technique than sawing flat pieces or square sections of wood, because of the shape of the dowel.

So first of all, we need to make sure that we clamp the piece of wood, so using a bench hook and a clamp, or a vice instead, in order to keep it in position, keep it in place.

So because of the shape of dowel, it has a tendency to roll and move outta position.

So we need to make sure we clamp it and secure it in place.

We need to make some indentations in the wood to help us get started with the sawing.

To do that, we need to lightly pull the blade towards you, as you can see in the little animation there, little video.

You need to reset the saw and repeat that movement and then reset it again and repeat it again.

At least three times of making that backwards movement will make some little indentations in the wood.

And as Sofia's reminding us there, holding and cutting dowel can be tricky without splintering the wood.

So making those small marks to start with, those little indentations, will make it easier to locate the saw and to completely saw through the piece of wood.

So first task then in this section of the lesson is to use the measurements from your design and that accurate sawing technique to measure and cut the length of dowel that you will need to make an axle, a crank handle, and three followers, or one or two, if that's in your design.

So use the measurements from your design to cut those sections, those components, for your cam mechanism.

Pause the video while you get on with that task and come back when you've done.

Okay, how did you get on with that task? Hopefully you've got those pieces in order.

So you can move on to the second part of the task.

So this is where we need to make those extra components to make that cam mechanism.

So we need to make three, or one or two if that's in your design, thick cardboard circles, and these are going to be for the follower.

So these are not the cam discs, these are circles for the follower, and they need to be about five centimetre diameter.

We need to safely pierce a hole in the centre of those, 'cause these are not the cam discs, so they all need a central hole.

And to do that safely, you need to place some sticky tack underneath and use a sharp pencil so that you can make that hole safely in the centre.

And you're going to push the followers, that's the piece of dowel that you've cut for your follower into that hole.

Now, it should be a really snug fit, a really tight fit, because we don't want those to come loose.

If they are a little bit loose or you want to make sure they're extra secure, apply a little bit of glue or tape around the base of the dowel and where it meets the cardboard to hold it in place if you need to.

So you should have three cardboard discs with a hole in the centre to attach to your three followers, or one or two, if that's what you've done in your design.

So you end up with three followers with cardboard discs attached.

When you've done that using thick cardboard again, draw and cut out your three cam disc shapes in the correct size and shape for your design and safely pierce holes in those two, but this time you need to make sure the holes are in the correct place for the cam disc that you've made.

So remember, it's off-center for an eccentric, in the widest part for a pear, in the centre of the circular part for a snail, and in the centre for ellipse.

And again, make sure they are a tight fit with the dowel that you are going to pierce through.

So that's the piece of axle that you cut before is going to go through the middle of those cam discs.

There needs to be a tight fit so that they don't spin on the axle.

They need to move with the axle.

Pause the video, come back when you've done that part of your mechanism.

Okay, how did you get on? Hopefully you've got all of those component parts ready to move on to the next part of the lesson.

So you should have cut an axle and a handle from the dowel that you've still got in place.

You should have made those three followers with the cardboard discs on the end of each one, and we should have three, or one or two, cam discs ready to put onto your mechanism.

So the shape of those will depend on your design, but you need all of those components ready to move onto the next part of the lesson.

So the second part of the lesson then is where we're going to look at safe drilling techniques.

So we need to drill a hole in one of the components for our mechanism.

So we need to make sure that we can operate the drill safely so that we can drill the hole accurately as well.

So let's move on to that part of the lesson.

These are the tools and equipment that we will need to drill holes safely to create our crank.

So it's the crank component of the mechanism where we need a hole.

So you're going to need a vice, so that's to hold the wood in place on the table.

You're going to need some square section wood, so just a small off-cut of square section wood.

You're going to need the small piece of dowel that we cut earlier in the lesson for the crank.

You're going to need a hand drill, and you're going to need the correct drill bit.

So the drill bit is the the attachment that goes onto the drill that drills the hole the correct size.

So you need to match the drill bit to the size of hole you need.

So that will depend on the size of dowel that you've used.

You need to match those so they are the same size.

Jacob and Sofia are getting ready to drill a hole in some wood and to stay safe, they need to remember to tie back any loose hair, to roll up their sleeves to get 'em outta the way of any tools or mechanisms that they might be using, they need to clear the table so they've got plenty of room to work, and they need to gather together all the tools that they need before they start.

They could also wear goggles and an apron if they wanted to as well.

So Jacob asked an adult to insert the correct drill bit into the chuck of his drill.

Now, this part can be quite tricky, so it is best to ask an adult to do this, because it needs to be made sure that the drill bit is in the chuck securely if it's going to work properly, if it's going to be safe to use.

So Jacob's done the right thing asking an adult to do that.

Now, there are specific types of drill bits designed especially for wood.

So not only do we need to choose the correct drill bit for the size of hole we need, but also in make sure it is one that is designed for use in wood.

So here you can see on the drill that Jacob's using, the chuck is on the end of the drill.

That's where the drill bit's going to go, and the rotating handle is the bit that he is going to use to operate the drill.

And we can see here in the close-up picture, that's the drill bit inserted into that chuck.

So quick check then, which part of the drill is going to hold the drill bit? Is it the chuck, the crank, or the handle? Pause the video, have a think.

Okay, what did you think? Which part will hold the drill bit? Well done if you said it is the chuck.

That is the end of the drill that can be opened and closed to hold onto that drill bit.

Okay, so Jacob makes two marks now in the piece of wood, the off-cut of wood, the square section wood, and that's going to show where he wants to drill the hole.

So we need two holes either end of that piece of square section wood, he's marked it off with a pencil so he knows exactly where the drill needs to be positioned.

And he secures that piece of wood into a clamp or a vice that keeps the wood in place on the table, and that's to hold it really still while we are drilling the hole.

Sofia positions the wood drill bit vertically on top of the marks that they made with the pencil, and she gently pushes it into the wood.

That will keep it in position.

Then she slowly starts to turn the handle in a clockwise direction.

So this will start to rotate that drill bit, which will start to eat into the wood.

She slowly increases the speed and the pressure.

So that means she pushes down slightly until the drill starts to push through into the wood.

And she continues until she's drilled through and then she rotates that handle in reverse in order to pull the drill out.

So by reversing the handle, she reverses the direction of that drill bit, which will mean it can be pulled out.

We can have a look at how this works in this demonstration video.

(drill grinding) (brush rustling) Okay, so quick check then, the drill handle should be rotated in a reverse motion to remove the drill bit from the wood after drilling a hole.

Was that true? Did I need to reverse it to remove it? Is that true or false? Pause the video.

Have a think.

Okay, well did you think? It was true.

You do need to rotate that handle in the reverse, anti-clockwise direction in order to remove the drill bit from the wood, and continuing to rotate the drill bit in a forward motion would cause the drill to keep drilling further through the wood, rather than releasing it.

So the dowel that we cut earlier for the axle, that was the longer piece of dowel that you cut, should fit snugly into one of those holes.

So if you've chosen the correct drill bit for the size of dowel that you're using, it should be a snug fit.

If it's not as snug as you'd like, you could add some wood glue to help secure that in place as well.

Once you've got that in place, then the smaller piece of dowel that we cut for the crank, the handle, that should fit into the other hole, and that's going to be the handle that we use to turn the axle.

So again, it needs to be a snug fit.

We don't want it to come out when we rotate it, we want it to stay in place.

So if the hole's cut to the correct size, it should be a snug fit.

If not, you might need to secure it with a little bit of glue.

So let's just recap those steps before you have a go at this task.

So to drill a hole safely, you need to choose the correct drill bit.

That's very important, needs to be a drill bit that's for wood, and it needs to be the right size for the dowel you're using.

You need to mark the position that you're going to drill a hole on the piece of off-cut wood that you you're using today.

You need to secure that wood in a clamp or a vice to the table so that it doesn't move anywhere when you are drilling.

You need to position the drill vertically above those marks where you are going to drill so it's in the right position.

You need to follow the steps that we looked at earlier, you might want to have a look at the demonstration video again, to drill the hole in through the wood.

And then you want to tidy up, sweep away that sawdust to make sure that you've got a tidy working environment for the next part of the lesson.

So that leads us to your task, then.

So first of all, you're going to use those steps of drilling the holes safely to mark out and drill two holes in the off-cut square section piece of wood that you have with you.

You need to make sure that you have drilled two holes, one that's roughly central and one that's a little bit off-center, or at either end of the piece of wood.

The holes need to be the same width as a dowel, so that means choosing the correct drill bit so that when you insert it, it has a very secure fit and it's not going to move anywhere.

Once you've done that, insert the dowel that was cut for the axle into one of the holes, and insert the small piece of dowel on the opposite side of the wood to make the handle.

They should both fit tightly.

Okay, pause the video while you have a go at that task and come back when you're finished.

Okay, welcome back.

How did you get on? Did you manage to assemble that first part of our cam mechanism correctly? Just check that you have got two holes, that you made two holes, one kind of central and one off-center, towards the end of the piece of wood, that the two holes were the same width as the dowel that you are using, so that meant choosing the correct drill bit, and that you were able to insert those two pieces of dowel, the longer axle piece on one side and the shorter crank handle piece on the opposite side.

If you've done that correctly and it looks like the diagram there, then you have made the axle and crank for your cam mechanism.

Well done.

Time for the last part of today's lesson, then.

So this is where we get to assemble those cam components to make that full cam mechanism ready for our automaton.

So let's have a look at how we're going to do that.

With all the correct components, so that's those individual parts, we can assemble a cam mechanism and insert it into a box frame.

So we should have a pre-built box frame ready to use for this task, and we should have our axle that we made earlier on in the lesson.

These are not to scale, they're just to show you the component parts that you will need for this part of the lesson.

You'll also need the cam disc that you may for your mechanism.

So you may have one, two, or three, depending on your design, and you'll also need those three followers that we made earlier in the lesson.

So that was the three pieces of dowel with the cardboard circles attached.

And remember, they needed to be thick cardboard circles so that they make good contact with our cam discs.

You're going to measure out and pierce a hole in the centre of the cardboard panel at each end of your box frame.

So these are the side pieces of your box frame.

You're going to mark out the centre of that panel, and you're going to pierce, with a sharp pencil or a tool, a hole through the centre of that cardboard panel.

So those are the side panels of your box frame.

The hole should be slightly larger than the width of the dowel that you used, creating a loose fit, and that will allow that axle to rotate inside that hole without getting stuck.

So we don't want a tight fit here.

We want a loose fit.

You're going to then pierce three holes in the top panel of your box frame.

So you can do this safely by putting some sticky tack underneath, holding some sticky tack underneath the cardboard panel, and using that sharp pencil from the top to push through and pierce a hole.

So you're going to need three holes if you use three followers.

If you only used one or two followers and cams in your design, then you'll only need one or two holes.

So make sure you match the holes to the number of cam and followers that you have in your design.

These holes should also be slightly larger than the dowel, because we're going to also need a loose fit on here, and it's going to allow those followers to move up and down freely in that hole without getting caught.

So these are going to be quite wide holes compared to the ones we were making in the wood earlier.

So true or false, quick check, the holes for the axle are on the top panel of your box frame.

Is the axle going to go through that top panel? Is that true or false? Pause the video and have a think.

Okay, what did you think? Of course it's false, because the axle is positioned horizontally through the side panels of your box frame.

Those top holes are where the followers are going to be.

Well done if you got that right.

So once you have those holes in place, then you're going to insert the axle through one side of your box frame.

So there shouldn't be anything on your axle at the moment, other than the handle that we attached earlier.

You're going to insert it through one side first of your box frame, through that hole that you've pierced in the side panel.

You're then going to position your cam discs onto the axle.

So while it's still loose inside the box, you're going to attach thread on those cam discs that you made earlier.

And then you can push the axle through the opposite side of your box frame in the hole that you paste on the opposite side.

So that should keep the axle in place and the cam disc should sit inside your box.

So you can see from this picture, there's two of the cam discs on the axle inside the box.

So you might have one, two, or three, depending on your design.

So that axle should be in place and the cam disc should be in place on the axle as well.

We're going to make some slides now.

So remember, these are the parts of a cam mechanism that support the followers and keep them in the right place.

And to make those slides, we're going to roll up some small rectangular pieces of card.

So just any type of thin card, recycled card will do for this.

Cut a small rectangle and roll it into a tube shape.

And you're going to push these into the holes in that top panel that we made earlier.

It might be a little bit of a tight fit.

You might need to widen the hole or tighten the tubes to get it in.

The tubes will start to unravel as you put them in, but that will create the tight fit.

So that's fine.

You shouldn't need to glue them in place.

They should automatically expand and fit into your hole once you get them in.

You're then going to insert the followers that you made earlier up through the holes.

So you need to go in through the side of your box frame and push them up through the holes that you've just put those slides in, and that's where they're going to be positioned.

Now, they need to be above the cam discs, and that 90-degree angle of having the cam disc on the axle directly underneath the follower is what's going to create that connection that will allow it to move the way we want it to.

So the follower needs to be a directly above each of the cam discs that you have on your axle.

So you might need to do a little bit of tweaking.

You might be able to move those cam discs up and down a little bit on the axle to make sure they stay in the right place.

So let's just go over those steps before you have a go yourself.

So first of all, you're going to mark all the holes that you need, one in each of the side panels and one, two, or three in the top panel for each of your followers.

You're going to pierce a hole in those side panels using a sharp pencil, and pierce the holes in the top panel in the same way.

You could do that safely, remember, by using a piece of a ball of sticky tack that you hold underneath the hole and you push through from the opposite side.

Then you're going to insert the axle and the cams, put those in the right place.

Then you're going to make those slides by rolling up the cardboard tubes and pushing through the holes in the top panel.

And then you're going to insert those followers directly above the cam discs.

And when you put your box frame the right way round, those followers should remain in position if they are directly above the cam discs, the cam discs will stop them from falling out.

So those are the steps for assembly that you are going to need.

Quick check before we start, then.

The followers sit where compared to the cam discs? Do they sit below the cam discs, above the cam discs, or beside the cam discs? Pause the video.

Have a think.

Okay, what did you think? Well done if you said above.

So those followers need to sit directly above the cam discs if they're going to be affected by their movement.

So your task then is to follow the steps for assembling your cam mechanism and insert it into your box frame.

It might be a little bit of tweaking to do to get it all to fit and work properly, but that is your task first of all.

So you need to check you have pierced the holes in the top and side panels, that you've positioned those cam disc onto the axle in the correct place, and you've positioned the followers directly above the cam disc to stop them from falling down, but also to make sure they're in the right position to make the right movement.

Pause the video while you go through those steps and come back when you've done.

Okay.

How did you get on? Hopefully you managed to get through all those steps and you managed to pierce holes in the top and side panels of the box frame, you positioned your cam disc on your axle in the correct place, and you positioned the followers directly above those cam discs in your box frame as well.

So we're nearly at the end of today's lesson.

It's been an exciting practical lesson where we've got to assemble some of the components of our cam mechanism ready for our automaton box design.

But what have we been learning about along the way? Well, we've learned that assembling those axles at a 90-degree angle will allow for a more accurate connection to the cam.

So we've learned that if they're not in the correct position, they're not going to work as we intend them to.

Components can be adjusted.

So you might have to have made some adjustments in that task in order to make yours work correctly.

And we've also learned that more than one cam can be added to the same axle.

So we may have a different number of cams than your partner or friend has done on theirs.

Designs sometimes require loose fit joints like we had with the holes for the axle and the followers.

And sometimes they require a tight fit joint, so where we connected the pieces of dowel to the drilled holes in the wood, they needed to be a tight fit.

And choosing the correct drill bit ensures that we get that correct fit, especially in a rigid, solid material like wood, we need to make sure we use the correct drill bit for that.

And drilling techniques need to be conducted safely.

So if we're going to drill a hole, we need to do it correctly, we need to do it safely, so that we end up doing what we wanted to do and we also end up doing it safely.

We don't hurt anybody or ourselves.

So lots of learning today's lesson.

Hopefully you've managed to get through all that.

I will see you again in another lesson, but it's goodbye for me for now.

Thank you for joining me.