Lesson video

Hello, thank you for joining me for your Design and Technology lesson.

My name is Mrs. Conway and I will be guiding you through your learning today.

So today's lesson outcome is I can explain the function of a laser cutter and use this knowledge to manufacture products.

Our keywords then are laser cutter, nets, and lamination.

I'll go through each one of these in a little bit more detail as we work through the lesson.

So the first thing we're gonna look at then is laser cutting.

So a laser cutter uses a high-powered laser beam to precisely cut or engrave materials like board, timber, metal, some polymers, and fabrics.

And here I've got an example of a laser cutter.

You may have one of these in your school or your workshop at school, and it will look slightly or may look slightly different to the example there.

There's lots and lots of different brands of laser cutters.

Now a laser cutter works by directing a powerful laser beam through mirrors or fibre optics to a lens.

That then focuses the light onto a material.

And here you've got an example of the inside view of a laser cutter, and you can see at the top you've got the laser head and at the bottom you've got the cutting tray or sometimes called the bed of the laser cutter.

Now depending on the machine settings, the laser cutter either cuts through the material or engraves onto its surface, and you as the designer or manufacturer can decide what you want it to do.

Let's look a little bit more closely at how an actual laser cutter works.

So first of all, we have the laser beam.

Now the laser beam is a powerful, focused light that's called a laser, and that's made inside the machine.

It then reflects off mirrors, and you can see the mirror just labelled there on the diagram.

And that mirror then basically moves it to the correct location.

Next, you then have a lens which focuses the laser at the point on the material where the engrave or the cut will actually take place.

And then you also have a small stream of air which blows just to keep things clean and also cool, and that's called the air assist, and you can see that shown there on the diagram.

That's the material at the bottom there and that is where that focused laser is hitting the material.

The focused laser then melts and vaporises the material to produce a cut or an engrave.

And powerful extraction is also used to remove gases and particles from within the laser cutter as well.

So if you've ever heard a laser cutter working in your school and you've heard that really big kind of whirring noise, that's the extraction working to remove all those particles from within the laser cutter.

Okay, quick check for understanding on that then.

What focuses the light onto the material in a laser cutter? Is it A, a mirror; B, the lens; or C, a prism? Pause the video here and just take a moment to think about your answer.

Okay, and the correct answer was B, a lens.

Well done if you got that right.

Now laser cutting is an example of CAM, and that can be available within schools and also for smaller batch manufacturing as well.

So laser cutting, however, can also be used on an industrial scale, cutting things such as sheet metal for car bodies as shown in the picture there, or components for aircraft and spacecraft.

Laser cutting is also used in construction as well for cutting things such as large steel beams or even to actually manufacture some medical devices as well, such as things like stents as shown in the picture or pacemakers.

Okay, another quick check for understanding then.

What can a laser cutter be used for in industry? Click any that apply to this.

So A, car bodies; B, gears inside gearboxes; C, plastic bottles; or D, medical devices.

Pause the video here and just take a moment to think about your answer.

And the correct answers are A, car bodies, and also D, medical devices.

Well done if you got that right.

Now, what are the benefits of using a laser cutter? If you'd like to take a moment to think about if you can work any of these out for yourself, please feel free just to pause the video and take a moment to think about this question.

Okay, so Lucas has come up with a bit of an idea for this.

So Lucas has suggested, "It can cut out very detailed shapes with finished edges, which makes it great for creating neat, high-quality parts." Alex has also suggested an idea as well.

"Because the laser cutter doesn't touch the material directly, there's less chance of damage and the cuts are very precise." Both of these are great benefits of using a laser cutter.

So Sam has also suggested an idea.

"Parts can be tessellated, which helps reduce waste, saving money and reducing material environmental impact." So Sam's thinking is that actually the parts that are being cut out can be tessellated, so put really closely together.

That will hopefully then reduce any waste and really just help cut down on kind of saving money and also that environmental impact.

And Laura's also suggested something.

"Laser cutting is often used in schools, factories and design studios because it saves time and also produces consistent outcomes." That's a really big benefit to laser cutting as well.

Okay, it's gonna be over to you now.

I'd like you to work on these two tasks.

So the first thing is using notes and diagrams I'd like you to describe how a laser cutter works.

The second task, I'd like you to explain why laser cutting would be a suitable process to make the Christmas decoration shown in the image there.

Okay, pause the video here to have a go at these tasks and good luck.

So the first thing I asked you to do was, using diagrams, describe how a laser cutter works, and your diagram will hopefully look a little bit like the example there, so just compare yours to mine and see if you've missed any of the key parts out.

Your description then.

Let's just look at an example, and again, compare yours to this and see if you've got the key points included in your answer.

"A powerful focused light called a laser is made inside the machine.

The laser reflects off mirrors to move to the correct location.

A lens focuses the laser at the point on the material where the engrave or cut will take place.

A small stream of air blows to keep things clean and cool.

The focused laser then melts and vaporises the material to produce a cut or engrave.

And powerful extraction is used to remove gases and particles from within the laser cutter." So as I said, just check your answer against this and see if you've got all the key points.

The second thing I asked you to do then was to explain why laser cutting would be a suitable process to make the Christmas decoration.

So let's look at example answer and again compare yours to this.

So, "By laser cutting the decoration, you can achieve a detailed design that will be cut out accurately.

Because the laser doesn't actually touch the material, the material will not be damaged and it will result in a high quality product.

The laser cutter can also cut the decoration quickly so that many of them can be made in a batch quickly and efficiently." Obviously, anything that is done quickly and efficiently is really good when it comes to commercial sales.

Okay, as I said, just compare your answer to that one and check if you've got the key points.

If you've got anything else on top of that, brilliant.

Right, next we're gonna look at manufacturing with a laser cutter.

Now, to make 3D prototypes using CAD on a laser cutter, designers need to consider how to turn a 3D design that they have done maybe by drawing it or by using a piece of CAD software into 2D shapes, because we are working very much in a 2D format when using a laser cutter.

Now there are different approaches a designer can take, but two possible ways are nets and also lamination.

Now a net is the flattened out shape of an object, such as a box.

So here is a box and this is what the net of that box would look like.

Now the net would be drawn out on a CAD application and then cut out on the laser cutter as a 2D shape before then being assembled into the 3D box.

The other alternative then is lamination.

Now lamination is the process of building objects by stacking and bonding multiple layers of material.

So, if for example you have this 2D shape here drawn using CAD, there would be multiple copies of the same shape that are cut out on the laser cutter and then those would then be glued together, so coating like these layers.

So here are those multiple shapes of that 2D CAD drawing being cut out on a laser cutter.

Quick check for understanding on that then.

What is the process of building objects by stacking and bonding multiple layers of material called? Is it A, casting; B, nets; or C, lamination? Pause the video here just to take a moment to think about your answer.

And the correct answer? It was lamination, well done if you got that right.

Now, lamination results in a really strong and solid product.

So here we've got those 2D shapes.

We have got all of those layers being cut out and they have been glued together, and that results in quite a solid outcome.

It's got a lot of strength in that, that lamination actually builds strength.

Now to turn a 3D design into 2D shapes, kind of going backwards from your 3D drawing or your 3D CAD, you first need to decide on the method of construction.

So in this example, Sofia has decided to make her product using lamination.

So this is her product, we're looking at a speaker here, and she's decided to use lamination to create it.

Now the way she's actually gone about this then is she's used a laser cutter and used 2D shapes to build it up.

I'd like you to have a little look at this.

Can you work out which shapes you would need to draw on 2D CAD to be able to create this product? Have a little think about this and feel free to pause the video here to do so.

Okay, so let's look at the shapes that we're going to need.

Now the first thing we're gonna need is the main body of the speaker, as that's made up of layers of the same shape, and this is roughly what that shape was.

So you've got the rough kind of outline of that main body of the speaker, and there was also two holes in it as well where the actual speakers were sitting.

So what we would need to do with that is actually put those and bond those shapes together, creating that lamination to build that 3D strong, solid object.

Multiple copies of the shape would be cut out on the laser cutter before glueing the layers together on the surface of each panel.

Now Sofia also has the additional decorative element to her design on the right-hand side of the product, and hopefully you can just see that, there's kind of like rectangular shapes on the end.

And this is what these would look like, so we're looking now on a different kind of angle of looking at these, so flat, that is what that shape would look like.

And again, this would also have to be cut out on the laser cutter.

So these would be drawn and cut out separately to the main body shape.

So how would Sofia work out how many copies of the shapes she would need? Pause the video here and just take a moment to think about that question.

So Sofia would need to decide the dimensions of her product first.

And Sofia has decided that her product will be 200 millimetres deep.

She would then decide what thickness material she's going to use to cut each layer.

And Sofia has decided she's going to use 9-millimeter laser ply.

Now she's actually now got all the information she needs to be able to work this out.

She would then need to divide the depth of the speaker by the thickness of the material to work out how many copies or layers she would need to have cut on the laser cutter.

So the depth of the product, as I said, is 200 millimetres.

Sofia has decided it is 200 millimetres.

That would then be divided by the thickness of the material, and if you'll remember, the thickness of the material she chose was 9-millimeter.

That would mean that she would need 22.

2 total copies or layers of her cutout.

Now Sofia would round down and cut out 22 layers of her shape.

This is only 22.

2, so she would round that down.

So she'd cut out 22 layers of her shape in the 9-millimeter laser ply.

Quick check for understanding on that then.

If Sofia actually wanted her product to be 300 millimetres deep, instead of the 200, so 300 millimetres deep, and was using 12-millimeter-thick ply, how many copies of her shape would she need then? A, 22; B, 25; or C, 29? Pause the video here and just take a moment to think about your answer.

And the correct answer? It was 25, well done if you got that right.

Now Sofia would fit as many templates of her shape onto one sheet in her CAD file.

This is called nesting, or sometimes tessellating.

Now it would depend on the size of the bed of the laser cutter as to how many she could fit on, as laser cutters tend to all have different-sized beds.

She would then need to export her design either as a DXF or an SVG file before importing it into a programme that can then communicate with the laser cutter.

Sofia would then need to adjust the speed and power on the laser cutter so that they are correct for her chosen material and also her material thickness.

Now the speed is the speed that the laser travels over the surface of the material, whereas the power is the intensity of the laser.

And those do have to vary if you have thicker or thinner material or different types of material.

Your laser cutter will usually have a manual or instructions as to the kind of power and speed to use for different materials and material thicknesses.

Over to you then to complete a task.

I'd like you to prepare your prototype for manufacture by drawing out the 2D elements that you would use to make up your 3D design.

Now if you're using an alternative CAM process, prepare your components accordingly.

So the first part of this would only really work if you've chosen to use a laser cutter.

But if you're using any other form of CAM process, just prepare your components in whatever way is appropriate for that process.

Pause the video here to have a go at this task and good luck.

So Andeep has decided he can use the laser cutter for his art storage box, and so he's decided to draw some panels for his art storage box.

So let's just remind ourselves of Andeep's design, this was his final design.

And these are his 2D CAD panels that he's going to laser cut.

Now you can see on these he's actually already prepared them with the comb joints around the outside.

Now he decided to make it in panels, so rather than using a net or lamination, he's actually going to create panels and then join them together using those comb joints.

So these are actually just the side panels of the box, he would have a lot more to make on top of this, but it's just showing you the examples of the side panels for now.

Have a little look at yours.

Do you think you've included all of the components and all of the elements for your design? Have you got enough copies if you're doing something like lamination, for example? If you're doing a net, you might wanna test it out on paper first just to make sure the net's the correct measurements, the correct dimensions, and that it's going to go together correctly.

Okay, let's summarise today's lesson then.

So today we've been looking at laser cutting.

Now a laser cutter uses a high-powered laser beam to precisely cut or engrave materials such as board, timber, metal, some polymers, and fabric.

And a laser cutter works by directing a powerful laser beam through mirrors or fibre optics to a lens, which then focuses the lens onto a material.

To make 3D prototypes using CAD on a laser cutter, designers need to consider how to turn a 3D design into 2D shapes.

And lastly, there are different ways in which a laser cutter can be used to create a 3D product from 2D shapes.

Examples of this are things like nets, lamination, and Andeep also showed you using panels.

Those can then be joined together.

Thank you so much for joining me for your lesson today and well done for all of your hard work.

I will see you soon.