1. An Electronic Food Timer
Technology & Design
GCSE Coursework
An Electronic Food Timer
RA Moffatt WELB
Technology Education Centre WELB

2. An Electronic Egg Timer
Situation:
A number of cooking operations are dependant upon
some type of timing device to ensure that the food is
prepared to the required standard.
Design Brief:
Design a contemporary ‘Egg Timer’ appropriate for a
domestic environment;
Identification & Analysis:
An electronic system is required incorporating a timing device
Some type of interesting product/casing design to house the electronics system and battery?
An output device – light / audible tone?

3. An Electronic Egg Timer
Recognition of Constraints:
My design, communicating and manufacturing
capability, knowledge and skills;
The type of manufacturing processes available;
Materials accessible;
Tools, machines and equipment;
Function and ease of use
Hygiene – ease of cleaning
Location of PCB and battery

4. An Electronic Egg Timer
Investigation & Research:
Design inspiration!! Where do I start?
Observe and analysis existing timers – mechanical, electrical - reverse engineering;
Research for ideas – internet, magazines, books etc
Reference to existing ideas or stimuli should demonstrate how these materials have influenced your thinking around the problem or stimulated the thought process / ideas?
Designing using Mood Boards & reference materials
Student: An knowledge of construction and manufacturing techniques and processes will be of benefit
when considering appropriate ideas / concepts when designing for manufacture.
Teachers should model (designing) demonstrate how we think, see shapes and form, use reference materials and mood boards to generate ideas. Also, show how an idea/concept can be developed in design detail and showing constructional details i.e. how the parts intend to fit together. Showing how the pcb, battery are located and secured?

5. An Electronic Egg Timer
Design Opportunities: Designing for Manufacturing
How will the parts fit together?
How will the PCB be mounted?
How will the battery be mounted securely and accessed?
How will the potentiometer be located?
How will the base be fitted?
How will the time be registered?
What type of output device will be required and where will it be located?
How can we include detail into the design to enhance the aesthetics?
Designing for manufacturing – students should show graphically how the parts fit together; use notes / annotation
to help explain your ideas / thinking!

6. An Electronic Egg Timer
Design a former from any one of the given block shapes that is appropriate for the vacuum forming process. The form should be suitable as a casing design for an Egg Timer.
The dimensions of the wooden blocks will be calculated by the teacher and this is the starting point for the student.
Knowledge of the vacuum forming process is important before starting to design.
Where possible use 2-3mm rigid polystyrene sheet to accommodate complex shapes which also provides rigidity and a feeling of quality.
Designing for Manufacture:

7. An Electronic Egg Timer
Suggested Idea 1
Suggested Idea 1

8. An Electronic Egg Timer
Former turned on the
Wood Lathe
Vacuum formed using
rigid polystyrene sheet
Suggested Idea 2

9. An Electronic Egg Timer
Inset - egg holder made from acrylic sheet. A basic CAD / Solid Works exercise.
Internal egg rack
Show sketches of your ideas for a base?

10. An Electronic Egg Timer
The electronic Egg Timer may have a dual function i.e. used to hold six hens eggs. The student could also design this feature.

11. An Electronic Egg Timer
The semi-sphere may be used as a basic geometrical shape for vacuum forming. Alternatively, you could blow mould acrylic sheet.
An interesting feature added to this form could be a design opportunity for the students.
A semi-sphere may be used as a basic geometrical shape for vacuum forming. This casing will house the electronic PCB and battery. Design an interesting feature that could be located to the base to show the different time delays.

12. An Electronic Egg Timer
Using graphics or model using CAD, to sketch different ideas for a feature which would add to the aesthetics - of this basic design;
The additional feature provides a design opportunity which should be quite controllable to manage for both the teacher and student.
How will this part be located?
How will the different time delays be indicated?
Pictorial view
Front view
Suggested Idea 3

13. An Electronic Egg Timer
Contemporary kitchen timers
Additional features!
How will the PCB & Battery be mounted?

14. A B An Electronic Egg Timer Inspiration!
How will part (A) fit-into part (B)?
How & where will the potentiometer be fitted?

15. B A An Electronic Egg Timer Suggested Idea 4
A simplistic design that should be quite easy to achieve. If, the height is reduced this shape can be
vacuum formed. The lower half could be turned from wood and inserted into the plastic tube if vacuum forming this height proves to be a problem. Part A could be turned in wood. The potentiometer could be inserted / interference-fit in the wood. However, a pre-set can also be used for this circuit design. A
Suggested Idea 4

16. An Electronic Egg Timer
potentiometer
Fitting the potentiometer?
base

17. An Electronic Egg Timer
Show details using graphics of how the potentiometer could be fitted to this design?
Suggested Idea 4 developed

18. An Electronic Egg Timer
A suggested idea that requires development and simplified for manufacture.
Suggested Idea 5

19. An Electronic Egg Timer
Fabrication: in acrylic plastic the top heated in the oven & then formed over a male / female former.
1) How will the base be attached to access the battery?
Suggested Idea 6

20. An Electronic Egg Timer
Suggested Idea 6 fabricated in acrylic plastic

21. An Electronic Egg Timer
The top may be made from birch plywood steamed and bent over a former or fabricated.
Contrasting woods may be an option?
Suggested Idea 6 fabricated in wood

22. An Electronic Egg Timer
This shape could be fabricated from 3mm acrylic sheet and the top press moulded over a former.
This form demands higher level precision and accuracy regarding manufacturing skills.
Suggested Idea 7 fabricated

23. An Electronic Egg Timer
Acrylic sheet heated in the oven and press-moulded
Acrylic sheet heated in the oven and Press – Moulded using a male and female former.
This process produces a quality form!
Male and female former
Outcome after trimming
Press Moulding

24. An Electronic Egg Timer
Finished & assembled

25. An Electronic Egg Timer
Sides glued using Tensol.
Suggested Idea 8 fabricated

26. An Electronic Egg Timer

27. An Electronic Egg Timer
PCB, printed circuit board
How will the pcb be mounted?
One student’s completed Egg Timer design.
The egg was turned on the wood lathe and then vacuum formed using rigid polystyrene sheet. The base was cut on the
band saw and sanded using the linisher or belt sander.

28. An Electronic Egg Timer
A GCSE student’s design outcome!