• 2.3 Project Design (1/4): Ask, Imagine, Plan

    • Learning Objectives:

      After this lesson, students can

      • know and apply the steps of engineering design cycle;
      • use SCAMPER skills in design ideas creation;
      • know the requirement and specification of the term project;
      • know some properties of MDF, a kind of manufactured wooden board.

    • 1. DESIGN CYCLE

    • There are many versions of design cycle. The following is a very simple one.


      1. ASK: Identify the problem
      2. IMAGINE: Brainstorm ideas
      3. PLAN: Design a solution
      4. CREATE: Make a model
      5. IMPROVE: Test and evaluate 

    • 2. SCAMPER (a concept generation tool for brainstorming)

    • SCAMPER is a quick, easy and direct form of creative brainstorming. You use the tool by asking questions about existing products, using each of the seven prompts above. These questions help you come up with creative ideas for developing new products, and for improving current ones.


      • Substitute
      • Combine
      • Adapt
      • Modify
      • Put to another use
      • Eliminate
      • Reverse

      (for more details) (Infographic)

      Example:

    • 3. DESIGN FACTORS

    • Design factors are the controllable factors that are suitably varied in order to obtain the desired performance.

    • 4. PROJECT: WIND DRIVEN TOY CAR

    • SPECIFICATION

      Dimensions

      • smaller than 17 cm (W) x 17 cm (H)
      • can be stored in the store room shelf


      Material / Components

      • MDF (mainly), A4 sized, 5mm thick (1 piece)
      • Popsicle sticks
      • Wooden blocks
      • Wooden rods
      • Drinking straws
      • Other recycled / reused material, e.g. plastic bottle caps (provided by students)
      • 3V dc motor (1 piece)
      • AAx2 battery case (1 piece)
      • Plastic propeller fan (1 piece)
      • AA batteries (NOT provided)

    • 5. MATERIAL: MDF (MEDIUM-DENSITY FIBREBOARD)

    • There are 3 categories of wood:
      1. Natural wood
        1. Hardwood
        2. Softwood
      2. Manufactured boards

      MDF is a manufactured board. It is a man-made wood. It is made from recycled wood that has been shredded to make small wood particles. They are then glued together with PVA glue and pressed and baked to make large sheets of MDF.

      MDF is often used in school projects because of its flexibility.


      How MDF is made?



      Advantages of MDF

      Now that we know what MDF is composed of, we are sure you want to know how good or bad it is.

      • MDF is generally cheaper, when compared to plywood
      • The surface of MDF is very smooth and makes for a great base for painting
      • Thanks to the smooth edges, it is easy to cut and carve designs out of MDF
      • It is denser and stronger than particle board


      Disadvantages of MDF

      Like every other material, MDF also comes with its set of cons:

      • MDF soaks up water and other liquids like a sponge and swells, if not sealed well
      • Since MDF is a dense material, it is very heavy and difficult to deal with
      • Being made up of fine fibre, it does not hold screws very well
      • MDF easily suffers damages and sags, if not handled with care

      Comparision of MDF with Other Woods

    • Further study: Some basic wood joints



      Because of the propeties of MDF, Butt joints will be used and the boards are joined by white glue.


    • 6. PROJECT EXAMPLE(S)

    • An Example (by Tinkercad)

    • 7. HOMEWORK

    • HW2.3.1 Design Cycle & SCAMPER (for Group 2 & 1) 測驗卷
      受限制的 無法使用，除非滿足下列任一條件：
      • 您屬於2A/2R GROUP 2。
      • 您屬於2S/2M GROUP 2。
      • 您屬於2T/2Y GROUP 2。
      • 您屬於2A/2R GROUP 1。
      • 您屬於2S/2M GROUP 1。
      • 您屬於2T/2Y GROUP 1。
    • HW 2.3.2 Draw your rough design on an A4 paper.
      • With necessary dimensions labelled.
      • The sizes and shapes of different parts should be reasonable.
      • Satisfy the project requirements.
      • You MAY need to submit it later.