Engineering Solutions

Curriculum Context

This lesson is designed for Year 11 students studying General Engineering in Australia, aligning with the Australian Curriculum: Technologies – Senior Secondary Pathways, Engineering Principles and Systems (Units 1 and 2). The focus is on conceptualising and developing innovative solutions to real-world problems, compliant with curriculum standards.

Specifically, this lesson addresses:

• Strand: Processes and production skills
• Content description: Investigating and defining problems, iteration during prototyping, and production to evaluate solutions for engineered systems (ACDE11-12).
• Skill focus: Engineering thinking, testing materials/forces, and designing mechanical components.

---

Lesson Overview

Topic: Designing a Mechanical Grabber Arm

Objective: Students will prototype a mechanical grabber arm using inexpensive materials to lift a small object (e.g. a plastic ball or similar).
The lesson aims to develop problem-solving, collaboration, and practical prototyping skills. Students will explore principles such as mechanical advantage, levers, and forces in their designs.

---

Prior Knowledge

Students should have a basic understanding of:

• Types of levers (first, second, third class).
• Simple machines and basic mechanics concepts.
• Brainstorming and iterative design.

---

Learning Objectives

By the end of this lesson, students will:

1. Define and model a mechanical system to solve a specific challenge.
2. Apply engineering principles to construct a simple grabber arm prototype.
3. Use critical thinking to evaluate the effectiveness of their designs based on performance.

---

Materials Required (Per Group)

• Cardboard sheets
• Wooden skewers or icy pole sticks
• Rubber bands (various sizes)
• String
• Paper clips
• Hot glue gun and glue sticks (teacher-supervised)
• Masking tape
• Small plastic balls for testing (approx. 5cm diameter)

---

Lesson Structure

1. Introduction (10 minutes)

• Hook (2 minutes): Start with a brief demonstration of a simple mechanical grabber arm (pre-built by the teacher). Use this to pose the question:
  "How can we design and build a tool to improve lifting small objects in situations where we can't use our hands?"
• Background Context (5 minutes): Discuss real-world applications, such as robot arms in manufacturing or mobility aids for people with disabilities.
  • Highlight Australia’s contributions to robotics/engineering to foster relevance.
• Objective Setting (3 minutes): Clearly explain today’s goal—designing and creating a working prototype of a mechanical grabber arm using limited resources. Display the materials.

---

2. Brainstorm & Sketch Ideas (15 minutes)

• Brainstorm (5 minutes):
  • In table groups of 4, guide students to brainstorm ideas:
    What kind of mechanisms can achieve a grabbing action? What type of levers would apply?
    • Encourage open-ended thinking but ensure focus on concepts such as:
      • Movement linked to levers.
      • Efficient force transfer.
• Sketch Design (10 minutes):
  • Students individually sketch their grabber arm design ideas using provided materials.
  • Emphasise labelling components (lever points, force application, fulcrums).
  • Use guiding prompts on the board:
    How will your design move? Which part will grip the object?

---

3. Prototype Construction (30 minutes)

• Distribute materials to groups. Work collaboratively to build prototypes based on their sketched designs.
• Guidance during construction:
  • Ask guiding questions:
    What forces are involved? How will you make the jaw of the grabber move?
  • Ensure safety when handling scissors, tape, or hot glue guns.
• Encourage iterative improvement:
  • Test as they build and tweak their designs.
  • Demonstrate simple concepts if groups face challenges (e.g. how a rubber band stores elastic energy).

---

4. Testing & Evaluation (10 minutes)

• Testing (5 minutes): Use a “grabber challenge” to test each group’s prototype:
  • Place the plastic ball within a small container at varying locations on a table.
  • Measure how effectively the grabber functions (e.g. grasping securely and lifting without dropping).
• Group Reflection (5 minutes):
  • Discuss each group’s results briefly.
    • What worked well? What didn’t? Why?
  • Encourage suggestions for how they could improve their designs in the future.

---

5. Debrief & Wrap-Up (5 minutes)

• Recap key learning points:
  • Connection of engineering principles to real-world applications (levers, forces, motion).
  • Importance of iteration in design.
• Highlight how today’s activity relates to future topics, such as CAD-based prototyping or advanced robotics.
• Assign a short reflection task for homework:
  Write 100 words about one way mechanical grabbers are helping people or industries.

---

Assessment Strategies

1. Observation: Take notes during group work on students’ participation, problem-solving, and teamwork.
2. Prototype Success: Evaluate the functionality of designs during testing.
3. Reflection Task: Assess students’ understanding of applications and learning from the activity.

---

Differentiation

• Support for struggling students: Provide pre-drawn lever diagrams and additional scaffolding (e.g., small group discussions).
• Extension for advanced learners: Challenge them to consider additional factors such as weight limits or energy efficiency in their designs.

---

Teacher Reflection Post-Lesson

1. Did students engage with the engineering principles effectively?
2. Were the materials and time sufficient for successful prototype building?
3. How could group management or testing refinement improve outcomes?

By providing a hands-on prototyping experience, this lesson gives students an engaging way to learn key engineering concepts while fostering creativity and teamwork aligned with the Australian Curriculum.