IT · Semester 1 · Chapter 3 · Book pp. 57–76
Plan, Create and Present
วางแผน สร้างสรรค์ และนำเสนอ
Non and Namwan have their designs. Now they plan the work, build the crusher and start the rules, test whether each one really solves the problem, improve them, and present everything they did.
Learning objectives จุดประสงค์ของบทเรียน
By the end of this chapter you can:
- Plan the work before you start building.
- Choose tools that suit the job, and use them correctly.
- Test, evaluate and improve your work.
- Present your results in a suitable way.
In this chapter: 3.1 Planning · 3.2 What to know before you build · 3.3 Testing, evaluating and improving · 3.4 Presenting
Apply it: vetiver grass
Real problems, big or small, are only solved after testing and improving many times. King Bhumibol (Rama IX)’s royal project spent more than 10 years researching vetiver grass to stop soil erosion. Its long roots grow straight down and knit together, holding the soil and keeping water in it. They are also home to soil microbes, which makes the soil healthy again.
📖 Review before you start
In M.1 you learned that materials share some properties and differ in others, such as hardness, toughness, elasticity, and how well they carry heat and electricity. Choose materials that suit the job. Tools come in many kinds (for measuring, cutting, joining and drilling); some are simple, others have mechanisms, electrics or electronics and need more skill. Whatever tool you use, it must suit the material and the job, and be used safely.
🧑🔬 The Doctor asks
How can we build our work quickly, with as few mistakes as possible?
3.1 Planning the solution การวางแผนการแก้ปัญหา
Before you build or start the method, plan the work step by step. It saves time and cuts mistakes. Break the job into smaller tasks, list the activities for each, and give each one a time and the person responsible. (If you do not know the exact time, estimate a range.)
You can show a plan in different ways, such as a flowchart of the steps or a schedule.
Non’s schedule (days)
| Task | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|---|---|---|---|---|---|---|---|
| Prepare materials and tools | yes | yes | |||||
| Make the crushing plate | yes | ||||||
| Make the lever | yes | ||||||
| Assemble all the parts | yes | ||||||
| Test it | yes | yes | |||||
| Improve it | yes | yes | |||||
| Paint and finish | yes |
Namwan’s schedule (days)
| Task | 1–3 | 4–6 | 7–9 | 10–12 | 13–15 | 16–18 | 19–21 | 22–24 | 25–27 | 28–30 |
|---|---|---|---|---|---|---|---|---|---|---|
| Meet the shops to explain the project | yes | |||||||||
| Tell students how the project will work | yes | |||||||||
| Measure the rubbish in the bins before the rules start | yes | |||||||||
| Use the rules | yes | yes | yes | yes | yes | yes | yes | yes | ||
| Evaluate: measure the plastic again and compare; ask students and shops about problems | yes | yes | yes | yes | yes | yes | ||||
| Use the results to improve | yes | |||||||||
| Sum up and write the report | yes |
💭 Think about it
If Namwan drew her plan as a flowchart, what would it look like?
🛠️ Activity 3.1 · Plan the work
From Activities 2.3 and 2.4, plan your work: the steps, how long each takes, and who is responsible. Show it in any form you like.
3.2 What to know before you build สิ่งที่ควรรู้ก่อนลงมือสร้างชิ้นงาน
Once the plan is ready, you follow it. Work with wood, metal, plastic or chemicals means thinking about safety: choose the right tool, use it the right way, and wear the right clothes.
Saws
Saws have different shapes, teeth and materials because they are made for different jobs. Choose the right one, and learn to use it properly.
| Saw | Used for |
|---|---|
| Hand saw เลื่อยลันดา | General wood cutting |
| Back saw เลื่อยรอ | Cutting joints and fine finishing work |
| Pruning saw เลื่อยโค้ง | Cutting small branches |
| Coping saw เลื่อยฉลุ | Cutting patterns that need precision |
| Bow saw เลื่อยธนู | Cutting fresh or dry branches, or logs into pieces to move or build with |
⚠️ Using a saw safely
- Choose a saw that suits the job.
- Hold the handle in one hand. With the other, hold the frame or steady the work so the blade stays straight and does not wobble or twist.
- Do not press too hard or saw too fast, or the blade can snap. Use just enough force to move the saw forward smoothly.
- Fix the blade tightly to the handle so it cannot come loose.
- Dress for the job: safety goggles against broken metal if the blade snaps, and safety shoes against heavy objects.
💡 Did you know? Why saw teeth differ
Each tooth has three angles: the cutting angle (A), the edge that cuts; the rake angle (B), which pushes the sawdust out; and the clearance angle (C), which cuts friction between tooth and work and keeps the edge sharp. Saws for hard materials have a wider cutting angle (50° instead of 45°), so their teeth are stronger.
Non builds the crusher
First the crushing plate. It is made of steel, so it is strong and heavy enough to press the rubbish down. The steel parts are joined by welding.
Next the bin clamp: hollow steel cut to the width and curve of the bin edge, bolted to the lever. The joint between the clamp and the lever is welded so it moves freely and the lever goes up and down easily.
Namwan starts the rules
- She meets the canteen shops: no more single-use cups (shops buy reusable ones), no more straws, and 2 baht off for students who bring their own cup.
- Signs and school announcements tell students the details and the start date.
- Before the start, she measures how high the plastic rubbish is in the busiest bins, so she can compare before and after.
- The rules start on the planned day.
🛠️ Activity 3.2 · Do the work
Follow your plan. Photograph the finished product and list the tools you used for each part. If you solved the problem with a method, photograph the work as it happens and describe the steps briefly.
3.3 Testing, evaluating and improving การทดสอบ ประเมินผล และปรับปรุงแก้ไข
A test shows whether the product or method solves the problem you set. Start by setting test criteria: clear, linked to the problem, concrete and measurable. Then compare the results with your goal. If they fall short, use them to improve the work.
Some things cannot be tested for real because it costs too much. You cannot smash a house to test its strength! Instead you test it on a computer, or test parts of it, such as the strength of the steel, so people can be sure the house will not fall down.
The Rockwell hardness test presses a diamond tip into the steel (diamond is very hard) with a set force for a set time, then measures how deep the dent is. A deep dent means soft steel. Modern machines show the hardness as a number straight away.
If the work still has faults after testing, go back and improve the design, change the materials and so on, then test it again against the same criteria, until it solves the problem.
Testing Non’s crusher
His problem scope was to crush bottles and cups so the bins have more room at lunch. His criteria:
- How far does the rubbish really go down, compared with the 12 cm in the design?
- How well does it work: how many bins of rubbish fit in one bin, and is it easy to use?
- Fair test: the same amount and type of rubbish each time (plastic cups and bottles), and new, uncrushed rubbish each time.
Test 1 · How far the rubbish goes down
Three people each crushed rubbish filled to ¾ of the bin, once. The rubbish went down 7 cm, 9 cm and 8 cm, so it did not reach the 12 cm in the design.
🔴 Problem found: cups slip through the plate
Some plastic cups slipped out through the gaps in the crushing plate. Non closed the gaps by welding in more steel bars, parallel to and across the old ones.
Retest: the rubbish went down 12 cm, 11 cm and 13 cm. On average, that matches the design.
Test 2 · How well it works
Three people crushed ¾ of a bin, added more rubbish up to ¾, crushed again, and kept going until it would not crush any more. They fitted 1.5, 1.8 and 1.2 bins of rubbish: on average 1.5 bins in one bin.
All three said it was easy to use, the lever was not too heavy, and it was a good height so their arms did not get tired. But the clamp slipped off the bin edge while they used it.
🔴 Problem found: the clamp comes off
Nothing held the clamp when the lever was pushed forward, so Non added a clamp on the top edge of the bin in two places.
Tested again, the crusher worked well and the clamp stayed on. The rubbish went down 10–12 cm each time, it held 1.5 bins on average, and users found it easy. Then Non painted it and finished the details.
Testing Namwan’s rules
| Test | Result | Evaluation |
|---|---|---|
| Measure the plastic rubbish in the bins and compare before and after the rules | The rubbish was lower by 5 cm (week 1), 5 cm (week 2), 7 cm (week 3) and 8 cm (week 4) | The rules reduced plastic rubbish in the school |
| Ask students and canteen sellers: do they understand the aim, are the rules hard to follow, any problems? | They understand the rules are there to cut plastic, the steps are easy, and there were no problems | Students and sellers cooperate well |
Plastic cups and bottles went down steadily for 4 weeks, and most people understood the aim without any trouble. The rules worked, so Namwan keeps them going and checks them regularly. If a problem comes up, she will use the results to improve them.
🛠️ Activity 3.3 · Test your work
After Activity 3.2, set test criteria that match your problem scope. Record how you tested, the results, your evaluation, and how you could improve the work.
3.4 Presenting การนำเสนอ
A presentation helps others understand every step of how you solved the problem: what the problem was, the data you gathered, the design, the building, the tests, how you improved it, and any problems along the way. It is also a chance to share what you learned and get ideas to develop the work further.
- Set the topics and limits. Write the topics in the order you will talk about them, then add the details.
Fig 3.10Planning the topics: the problem, how it was solved, the test results, the improvements - Choose the media and format. Think about the time (if it is short, keep it short and clear) and the
audience (pictures for children; graphs or tables for adults). You could use a poster, a talk with slides, or an
infographic, still or animated.
Fig 3.11An infographic of King Bhumibol’s New Theory Agriculture: divide the land 30:30:10:30, for a pond to store water and raise fish, rice fields, the house and animal pens, and fruit trees, vegetables and herbs to eat and sell - Use clear language and tell it step by step. Stress the key points. Ask and answer questions to keep people
interested, and invite suggestions to improve the work.
Fig 3.12Presenting by talking to the class
💡 Did you know? Presentation apps
Programs and apps, free and paid, help you make animations and infographics. Many have ready-made templates. More: ipst.me/9129
Chapter summary สรุปท้ายบท
- Planning the steps and time before you build cuts mistakes and saves time and resources.
- Choose materials, tools and equipment that suit the job, and use them correctly and safely.
- Before testing, set criteria so the test has a clear, measurable goal. Compare the results with the problem; if it is not solved, use the results to improve the work.
- Then present the whole process, including problems along the way, and listen to suggestions so you can develop it further.
🎤 End-of-chapter activity · Present your solution
Present everything your group has done. Decide (1) the topics, (2) the format, and (3) record the questions, comments and suggestions from your audience.
Mini-quiz
Source: IPST (สสวท.) Basic Science and Technology textbook, Technology (Design and Technology), Grade 8 (M.2), Chapter 3. Figures are from the textbook; text translated and adapted by Guru Jazzy.