Hello there.

My name's Mrs. Taylor, and I'm really pleased you can join me for the lesson today.

Our lesson today is Minimising material waste, and this is part of the unit Principles of materials and manufacturing.

The outcome: I can use materials efficiently.

We have four keywords.

Accurate, which means to be correct and precise, with no mistakes.

Efficient: using materials in a way that minimises waste.

Tessellation: arranging identical shapes in a repetitive pattern without gaps or overlaps.

And nesting: arranging varying shapes onto material to make the best use of space.

And in this lesson, we have three learning cycles: minimising waste, stencils and templates, and nesting.

Let's begin.

Minimising waste is important when designing and manufacturing.

There are two main reasons for this: environmental benefits and economical benefits.

Let's have a quick check.

What are the benefits to minimising waste when designing and manufacturing? Is it A, ergonomic; B, environmental; C, functional; D, economical? Pause the video and have a go.

Well done.

Let's check.

That's right, it's environmental and economical.

The environmental benefit of minimising waste is that fewer materials are required and therefore more natural resources remain.

For example, iron ore is mined from the earth and then processed using high temperatures to produce steel.

The environmental impacts of steel production are: iron ore is a natural but a finite resource, which will run out.

Mining damages the environment.

Lots of energy is needed to achieve the high melting temperatures.

And a quick check.

What are the environmental benefits of minimising waste? Is it A, fewer materials required; B, increases energy consumption; C, more natural resources remain; or D, saves money? Pause the video and have a go.

Wonderful.

Let's check.

That's right, it's A, fewer materials are required and C, more natural resources remain.

Fantastic.

Efficient manufacturing uses materials in a way that minimises waste.

The economic benefit of minimising waste is that fewer materials are required and therefore the cost of purchase is reduced.

This also means that businesses can be more profitable.

Efficient manufacturing requires accurate measuring and marking of materials.

Accurate refers to being correct and precise, with no mistakes.

Let's have a check.

Correct and precise is the definition for which word? Is it A, accurate; B, efficient; C, exact; or D, precise? Pause the video.

Have a go.

Let's have a look.

That's right, it's accurate.

When we mark out materials, it is helpful to remember the phrase: measure twice and cut once.

In other words, check the measurements and the marking out before cutting.

If the measurements and markings are checked before cutting, anything incorrect can be altered so materials are not wasted.

Task A.

The first part is to explain why manufacturing businesses need to minimise waste, and then explain the term measure twice and cut once.

Pause the video.

Let's have a look at some of the answers.

Manufacturing businesses minimise waste to save money and be more profitable.

They also minimise waste as this is better for the environment and that's good for their reputation.

Part two, explain the term: measure twice and cut once.

This means checking your measurements and marking are accurate before cutting materials.

Anything which is not correct can be changed before materials are wasted.

Well done.

The second learning cycle is stencils and templates.

Stencils and templates can be used to mark out accurately and quickly.

They can also be repeated easily.

Here's an example of a template, an ellipse template, which you may have seen in your own school.

Let's have a check.

What are stencils and templates used for? A, to mark out quickly; B, to measure material thickness; C, to mark out accurately; or D, to mark out when you don't have a ruler.

Pause the video and have a go.

Well done.

Let's have a look at the answers.

That's right.

That's right, it's A, to mark out quickly and C, to mark out accurately.

Standard stencils and templates can be bought.

These are often for shapes such as circles, ellipses, or letters.

Sometimes it is necessary to make a template for a specific task.

These can be made from cardboard, paper, or polymer.

Each piece of this lamp arm has a part circle shape at the end to allow for movement.

A circle template was used to mark this one out before it was cut and fabricated.

We can now watch a video of the lamp moving.

Paper template pieces are used to mark out fabric.

These are known as pattern pieces.

A quick check.

What can stencils or templates be made from? Is it A, fabric; B, paper; or C, polymer? Pause the video and have a go.

Well done.

That's right, it's B and C.

Both paper and polymer can be used to create stencils or templates.

Here is a sheet of A4-sized material and a template.

Here is a sheet of A4-sized material and a template.

Please note, the images are not drawn to the same scale.

We have an A4 sheet sized.

We have an A4-sized sheet of material which is 297 millimetres by 210 millimetres, and a template which is 40 millimetres by 40 millimetres.

How many templates could be cut from one piece of A4 material? We could work this out by placing a template on the paper and counting how many times it would fit.

The answer is 35.

However, this isn't the most practical method because we might not have all the materials to hand.

A quicker way to work this out would be to use a calculation.

Calculate the width of the material divided by the width of the template.

So the width of the A4-sized material is 297, and the width of the template is 40.

So we do 297 divided by 40, which equals 7.

425.

And then the height of the material divided by the height of the template.

So we have 210 as the height of the A4-sized material and 40, the height of the template.

210 divided by 40 equals 5.

25.

Then round down to the nearest whole number and multiply the total number of templates across the width with the total number of templates across the height.

So 7.

425 becomes 7, and 5.

25 becomes 5.

7 x 5 = 35.

Here is task B.

Part one, calculate how many of this template could be marked out on the material, which is A3 sized.

The template is 50 millimetres by 50 millimetres, and the A3 material is 297 by 420 millimetres.

And part two, explain the benefits of using a template.

Pause the video and have a go.

Well done.

Let's look.

Jacob explains his answer.

I calculated the width of the material divided by the width of the template, which was 420 divided by 50.

This equals 8.

4.

And then the height of the material divided by the height of the template, which is 297 divided by 50, and this equals 5.

94.

I then rounded down to the nearest whole number and multiplied the total number of templates across the width with the total number of templates across the height so that 8.

4 becomes 8 and 5.

94 becomes 5.

So the calculation is 8 x 5, which equals 40.

Brilliant.

And part two, explain the benefits of using a template.

Using a template saves time as you can draw around it quicker than measuring and marking each one with a ruler.

It is also more accurate as each of the shapes are going to be the same.

Well done.

The third learning cycle is nesting.

Here is a hexagonal piece of card.

How many hexagons could you cut out of one piece of A3 card? It depends how the hexagons are positioned.

Here we can see two examples.

It depends how the hexagons are positioned.

We could place one in the centre of the sheet of material, but that would be wasteful, or we could position them like this.

This is an example of tessellation, where the same shape is positioned in a repetitive pattern without gaps or overlaps.

The advantage of tessellation is that more of the material is used and less is wasted.

Tessellation is, let's have a check.

Tessellation is A, different shapes are positioned in a repetitive pattern without gaps or overlaps; B, the same shape is positioned in a repetitive pattern without gaps or overlaps; or C, the same shape is positioned in a random pattern.

Pause the video and have a go.

Great.

Let's check.

That's right, it's B.

The same shape is positioned in a repetitive pattern without gaps or overlaps.

Well done.

Sometimes there are shapes which cannot be tessellated as they are not identical to each other.

However, manufacturers still need to use material efficiently.

The diagram on the right shows the blue shapes that are needed, but much of the grey material is wasted.

Nesting is when varying shapes are arranged onto material to make the best use of space.

The shapes haven't been resized, just rearranged to use the material more efficiently.

CAD software can be used to produce nesting.

Let's have a check.

What is nesting in relation to material usage? Is it A, resizing shapes to fit the material, or B, arranging varying shapes to make the best use of space? Or C, cutting shapes from materials randomly? Or D, using CAD software to design patterns for decoration? Pause the video and have a go.

Well done.

Let's look.

That's right, it's B, arranging varying shapes to make the best use of space.

This is a design for a tree decoration which slots together and will be cut from three millimetre sheet material.

Firstly, we can nest the pieces so they will require less space and be more efficient.

Then we can position the nested template on the material as close to the edge as possible.

Sometimes it is even possible to position the template in between previous cutouts.

Task C.

These are the pieces for a model stool which slot together with a circular seat on the top.

Draw the three pieces on paper.

Part two, cut them out with scissors.

Three, nest the pieces.

Four, what is the smallest piece of material needed to cut all of these pieces from? And five, explain what nesting is and how this helps manufacturers to minimise waste.

Pause the video and have a go.

Fantastic.

Let's have a look at some of the answers.

Here we have two of the pieces drawn on paper.

Part two, all three pieces have been cut out of paper.

And now part three, they have been nested together.

And part four, the smallest piece of material where all the pieces can be cut is 170 millimetres by 165 millimetres.

And part five, nesting is arranging varying shapes onto material to make the best use of space.

It is similar to tessellation, but more difficult as the pieces are different shapes.

Manufacturers use nesting to plan the material use and minimise waste.

Well done.

Here is a summary of our learning today.

Efficient material usage has environmental and economic benefits.

Accurate measuring and marking out reduces material wastage.

Stencils and templates can be used to mark out accurately and quickly.

They can also be repeated easily.

Tessellation and nesting are ways of minimising waste by positioning the parts to be cut so as many as possible can be cut from each sheet.

Well done and thank you for joining me today.