IT · Semester 1 · Chapter 2 · Book pp. 29–56

Design First

ออกแบบกันก่อน

Non and Namwan each found three ways to solve the overflowing-bin problem. Now they must pick one, design it properly, and show their idea to other people before they build anything.

Learning objectives จุดประสงค์ของบทเรียน

By the end of this chapter you can:

Analyse and choose the data you need, thinking about conditions and resources, to find a way to solve the problem.
Design a product or method that matches that solution.
Present your solution so other people understand it.

In this chapter: 2.1 Analysing solutions · 2.2 Creating design options · 2.3 Designing the solution · 2.4 Building a model

Apply it

Design matters, both for making something that solves a problem and for turning your ideas into something concrete that others understand. A design cuts mistakes and becomes the plan you build from. Think of product designers, and of architects drawing a building before anyone builds it.

📖 Review before you start

In the engineering design process you identify the problem from the situation, then gather ideas from reliable sources, including the data and conditions you need. That leads you to choose and design a solution.

💭 Think about it

To design a product or a method, what do you think you need to know?

Next: 2.1 Choosing an approach →

2.1 Analysing ways to solve the problem การวิเคราะห์แนวทางการแก้ปัญหา

Any problem can be solved in more than one way. Comparing the ways by their conditions and technological resources shows which one is possible and suits the situation best.

The 7 technological resources ทรัพยากรทางเทคโนโลยี

#	Resource	What it means
1	People คน	The users and makers of the technology. Their knowledge and skills are used to think, decide and carry out the whole process.
2	Data and information ข้อมูลและสารสนเทศ	Data from many sciences, experience, local wisdom and study. Data from reliable sources is analysed and turned into correct information you can decide with.
3	Materials วัสดุ	Each material has different properties, so choose one that suits the conditions of the work.
4	Tools and equipment เครื่องมือและอุปกรณ์	Make the work easier, faster, more accurate and correct. Think about their limits and whether you can use them.
5	Energy พลังงาน	Moves people and things and makes the product work. It is usually electricity, so it is often left out, but count it if electricity is a limit.
6	Capital ทุน	Money, budget, property, buildings and places. Some solutions cost a lot, so think about value for money.
7	Time เวลา	If the problem must be solved quickly, you may need a different solution from a long-term one.

Usually you only count the main materials of the product. Things like paper, stationery and printer ink are left out. Not every problem uses all seven resources.

Non’s analysis: the rubbish crusher

Resource	1. Lever	2. Scissor mechanism	3. Hydraulics
People	Know levers and moments	Know scissor mechanisms and sensors	High skill, e.g. electrical mechanics
Data	Levers and moments	Scissor mechanisms and sensors	Electrical mechanics
Materials	Strong, rust-proof	Strong, rust-proof	Strong, rust-proof crushing plate
Tools	Basic tools	Basic tools, sensors, solar panel	Tools and a hydraulic system
Energy	Your own push	Solar power turned into electricity	Electricity drives the hydraulics
Capital	Materials for the lever frame	Solar panel, sensors, control circuit	A hydraulic system
Time	Simple, quick to build	Not complex, quick to build	Complex, slow to build

This analysis fits Non’s situation (his budget, knowledge and skills). Yours may be different.

Lever: simple, quick and cheap to build. It uses your own push, but the lever makes that push easier.
Scissor: not complicated, but it has many moving parts, takes longer to build, may break down, and needs costly parts such as sensors and wiring.
Hydraulics: works very well, but needs special knowledge and skills, and is complex and slow to build.

✅ Non’s choice: the lever crusher

It is simple, he can build it himself, and he only has to pay for the lever frame and the bolts. It needs a person to push, but the lever reduces the force needed to crush plastic bottles.

Namwan’s analysis: reducing rubbish

Resource	1. Rules for shops and students	2. Leaflets and posters	3. Recycling bank
People	Director, team, teachers, students, shops	Team	Director, team, members (students, teachers, parents), scrap shop
Data	Rules that worked in other schools	Examples of eye-catching posters	Recycling banks that worked elsewhere
Materials	–	Paper	Account books and ledgers
Tools	–	Computer, printer	Scales, computer, printer
Capital	–	Printing	Fund to buy rubbish; a bank office and a store
Time	About 1 month	About 3 months	About 1 term

Rules: cheap and can work on time, but everyone must keep cooperating, and the director must approve because it involves the shops.
Posters: cost more (even more if you pay for nice ones), are not a rule, so students may ignore them, and work more slowly.
Recycling bank: organised, and rewards motivate students, but it has many steps and needs many people, and it does not directly cut the plastic in school.

✅ Namwan’s choice: rules for shops and students

It costs less, takes less time, has simple steps, and cuts plastic rubbish as well as the other ways do.

🛠️ Activity 2.1 · Analyse and choose a solution

Analyse the technological resources of the solutions from Activity 1.4 in a table like the ones above. Choose one, and give your reasons.

Next: 2.2 Design principles →

2.2 Creating design options การสร้างทางเลือกในการออกแบบ

With a solution chosen, you design the product or method. Use the principles of product design and your creativity, and make more than one design. Then pick the one that best fits the problem and its conditions.

2.2.1 Principles of product design หลักการออกแบบผลิตภัณฑ์

#	Principle	What to check
1	Function หน้าที่ใช้สอย	The most important. The product must do the job it was made for, to solve the problem or meet the need.
2	Safety ความปลอดภัย	Dangers from using the product, system or method can hurt the user. Toys, for example, must not have small parts or sharp edges.
3	Structure ความแข็งแรงของโครงสร้าง	Choose a structure strong enough for how and where the product is used.
4	Ergonomics ความสะดวกสบายในการใช้งาน	Fit the human body: comfort, the order you use it in, and limits that cause tiredness, like a chair the wrong height or a shelf out of reach.
5	Aesthetics ความสวยงามน่าใช้	An attractive shape, form, colour and surface draws users and can affect how they feel.
6	Maintenance การบำรุงรักษา	Parts that need changing or repairing should be easy to reach, and spare parts easy to find.
7	Cost ราคาหรือต้นทุน	Estimate the price before you plan, so the design fits the budget: fewer parts, fewer kinds of material, simple production, no special tools.
8	Material and process วัสดุและกระบวนการผลิต	Use materials whose properties match the job, not more than needed, with simple production, preferably made or found locally.

**Fig 2.1**Ergonomic design: a computer screen that adjusts to suit the user

Designers should also think about packing and transport, and the effect on the environment: designs that save energy, natural or recycled materials, and production with the least waste.

2.2.2 Creativity and design ความคิดสร้างสรรค์กับการออกแบบ

Creativity is thinking about a problem widely, in many directions, in new and useful ways, and mixing old ideas into new ones. Four examples from the book:

1. A thornless durian, bred by a farmer in Laplae, Uttaradit: easy to hold and open, and worth more

2. A parasitic wasp lays its eggs in pests such as caterpillars and fruit flies, so the pests die: pest control without chemicals

3. An eco-friendly coffee cup: an edible cookie cup instead of a plastic cup that is hard to break down

4. Pencils made from old newspaper: less wood is cut, and the paper is used again

More design ideas: ipst.me/9136

Next: 2.3 Showing your design →

2.3 Designing the solution การออกแบบแนวทางการแก้ปัญหา

You turn your idea into something concrete by sketching, drawing a diagram, drawing a flowchart, or writing the steps. All of them sum up your idea and show it to other people.

1. Sketching การร่างภาพ (for products)

A sketch shows the details of each part: its shape, form and how it works. A 2D sketch shows width and length. A 3D sketch shows width, length and height.

A lamp drawn in 2D (left) and in 3D (right)

Write the sizes on the sketch and keep the proportions close to the real thing. If the real object is twice as long as it is wide, draw it twice as long too.

💡 Did you know? Three kinds of 3D drawing

Oblique: the front is drawn flat, the side goes back at 45°. Good for objects with a detailed front

Isometric: both sides at 30° to the horizontal. It looks like the real shape

Perspective: lines meet at a vanishing point (VP), like seeing it from a distance. The most realistic

2. Diagrams การเขียนแผนภาพ (for methods)

A diagram shows the steps of a method in pictures, from the start to the result.

**Fig 2.2**Crossing a canal on bamboo: 1 find a bamboo clump and pick a stem, 2 cut it, 3 lay it across the canal, 4 walk across on it, 5 reach the other side

**Fig 2.3**Making salt: sea water passes through ponds where mud, then silt and sand, then gypsum (CaSO₄) settle out. In the last pond the water evaporates for 10–15 days, leaving salt (NaCl)

3. Flowcharts การเขียนผังงาน (for methods)

A flowchart shows the order of the steps from start to finish, with standard symbols.

**Fig 2.4**Going from home to school: Start → take a motorbike taxi to the end of the lane → Is the traffic jammed? Yes: take the skytrain. No: take the bus → walk into school → End

Non designs the crusher

Before he designs, Non collects the data he needs:

Where: the bin stands in the seating area near the canteen

Bin size: 55 cm high, 52 cm across the top, 39 cm across the bottom, a 3 cm rim, 3 mm thick

He also needs the users’ height: M.2 boys at his school are 155–165 cm tall. Then he draws three designs.

Design 1: a handle wide enough for both hands, a double-bar lever 100 cm long for stability and less force, a clamp shaped to the bin rim, and a round plate that covers the bin

Design 2: a single-bar lever to save cost and weight, and a clamp long enough to grip the bin edge

Design 3: a single-bar lever, a pivot plate that sits on the rim, a clamp that hooks under the rim, and a round plate easy to cut and join

He chooses design 3: it uses less material than design 1, so it is cheaper; its clamp grips as firmly as design 2; and it presses just as hard.

Design details. Lever and handle: 1-inch hollow steel pipe, welded. Plate: 3 mm steel sheet with a 2.5 cm-wide rim cut into a circle, and a frame of 2.5 cm steel pipe inside. Clamp: square hollow steel cut to fit the bin edge

⚙️ How it works

Pushing the handle with force F1 makes the plate press down with force F2. Using the lever rule F2 × L2 = F1 × L1:

F2 = (L1 ÷ L2) × F1 = (100 cm ÷ 25 cm) × F1 = 4F1

So the rubbish gets 4 times your push. The plate is set to press the rubbish at ¾ of the bin’s height so the plastic underneath is squashed too, and it pushes the rubbish down 12 cm, which frees up enough space.

L1 = 100 cm, L2 = 25 cm, and the plate presses the rubbish down 12 cm

💡 Did you know? Design software

Free and paid programs draw designs accurately and realistically, and changes are quick to make.

Programs for 2D design (top left), 3D design (top right) and flowcharts (bottom)

Namwan designs her rules

Stop plastic cups. Shops stop single-use plastic cups and use washable cups for anyone without their own. Users return the cups to a set place.
Stop plastic straws. Shops stop giving straws, and people drink from the cup.
Use your own cup. Students bring their own cups. At first, a drink in your own cup is 2 baht cheaper. The school provides a place and equipment to wash cups.

Canteen plan: the shops, the entrances, the place to return used plates and spoons, and the new place to return used cups (green)

Start → meet the team about the rules and how to use them → use the rules (stop plastic cups, stop plastic straws, students use their own cups) → evaluate (less plastic rubbish?) → End

🛠️ Activity 2.2 · Design a product or method

In your group, design as many options as you can for your product or method, and explain the key points of each. Choose the one that best meets your needs, and give your reasons.

Next: 2.4 Building a model →

2.4 Building a model การสร้างแบบจำลอง

With a sketch, diagram or flowchart ready, build a model first. You use it to study, check and present your idea: does it look good, does it work, is it strong, is it easy to use? At this level you will build two kinds:

Kind	What it is for	Materials
Shape model แบบจำลองแสดงรูปร่าง	Shows or studies the shape of the product. Quick to make.	Easy to fold, cut and join
Working model แบบจำลองการทำงาน	Tests how the parts work, such as a circuit or a mechanism. The shape does not matter.	Cheap and easy to find

**Figs 2.5–2.7**A shape model of a house; a working model that tests an electric circuit; a working model that tests hydraulics

💡 Did you know? Other models

Test models check whether a design works as planned, like crash-testing a new car before it goes on sale.
Computer models simulate how something works or test what affects it, like wind on a building or air flowing over a car.

Computer models: wind on a building, and air flowing past a car

Non’s working model

Non wants to test whether the clamp grips the bin as designed. He uses art board and bamboo sticks because they are cheap at the stationery shop near school and easy to cut to shape, and an old bucket with a rim like the real bin.

**Figs 2.8–2.9**The working model of the bin clamp, and testing how it works

The clamp held the bin firmly. When he pressed the lever, the plate moved straight down and stayed inside the bin. Next he will plan and build the real crusher.

💡 Did you know? 3D printers

A 3D printer makes models and products straight from a computer design, even complicated shapes, and they are no longer expensive. See one working: ipst.me/9138

Namwan did not build a model: each rule was already detailed enough to plan. (She could still try her rules out in a small group first, such as using her own cup and no straw.) Some methods do need a model to show how they work, such as a car-park layout, a hospital’s route for collecting medicine, or a New Theory Agriculture farm.

A model of a New Theory Agriculture farm

🛠️ Activity 2.3 · Build a model

Build a model of the product or method you designed in Activity 2.2, to study its shape or test how it works.

Next: summary and quiz →

Chapter summary สรุปท้ายบท

Comparing solutions by their conditions and technological resources shows which one is possible and suits the problem best.
Designing before you build gives you the details you need to make the product or carry out the method, shows your idea to others, and becomes the template for the next steps.

🎤 End-of-chapter activity · Present your design and model

Each group presents its solution, with sketches and the model, so others understand it.

Mini-quiz

1. How many kinds of technological resource does the book list?

2. Which design principle is the most important?

3. A chair that is the wrong height for sitting a long time breaks which design principle?

4. Which 3D drawing shows both sides at 30° to the horizontal?

5. Which is the best way to show the steps of a method, such as going from home to school?

6. Non’s lever compressor: lever 100 cm, plate 25 cm from the pivot. The rubbish gets how many times your force?

7. Non built a model from card and bamboo sticks to test whether the bin clamp works. What kind of model is it?

8. Why did Namwan choose “measures for shops and students” over the recycling bank?

Source: IPST (สสวท.) Basic Science and Technology textbook, Technology (Design and Technology), Grade 8 (M.2), Chapter 2. Figures are from the textbook; text translated and adapted by Guru Jazzy.