Phase 2: Conceptual Design (Contd.)

Students are being asked to design a simple device to crush aluminium cans. A student design team purposes four solutions to the problem. Below are the concepts developed.

DESIGN IDEA 1

1. Handwriting machine

2. Design making is programmed

3. Machine works on programmed circuit

DESIGN IDEA 2

1. Designing machine

2. It is manually operated

3. When user starts rotating the wheel, marker goes on to make patterns.

DESIGN IDEA 3

1. Egg CNC machine

2. It works on Electricity supply

3. Object rotates, marker makes vertical designs.

DESIGN IDEA 4

1. Digital Printing Machine

2. Machine works on electricity supply

3. Prints o the object is made using high temperature.

Below are identified and prioritised objectives:

1. Safety
2. Ease of use
3. Portability
4. Use of standard parts
5. Cost

Assign weightage for the stared objectives:

Objectives	Weightage
Safety	7
Easy to use	6
Portability	8
Use of standard parts	7
Cost	7

PUGH Chart:

Objectives	Design idea 1	Design idea 2	Design idea 3	Design idea 4
Safety	+	+	++	Datum
Ease of use	+	_	+	Datum
Portability	+	+	+	Datum
Use of standard parts	_	_	++	Datum
Cost	_	++	_	Datum
+score	28	29	42	---
-score	7	13	7	---
Total	21	16	35	---

The best concept selected is Concept 3.

Subsystems list:

Object placement(Material alignment): Displaying on screen or by indicating with LED whether the object is alligned in proper position or not.

Making designs: This involves system and user interaction. System allows user to make choose of pattern and colours.

Refillment of sources(ink,marker,crayon): As the sources ends the machine will alerts the user and have the function of refilling that it by self.

Justifications:

Design Idea No.	Objective	Score	Justification
1.	Safety	9	The machine is programmed and it does not cause any harm to the user or object in any way
	Ease of use	7	The machine is automatic and human interaction is not involved
	Portability	9	The machine is made of wooden blocks which is comparatively light in weight making it portable
	Use of standard parts	5	Except the circuit there is no any standard parts
	cost	6	Few parts of the machine are expensive. For example circuit for programming
2.	Safety	8	It is human operated and considerably safety to use
	Ease of use	4	Since the machine is manually operated so the machine is user friendly
	Portability	9	The material used is only cardboard thus the machine is light weight and portable
	Use of standard parts	3	There is no any use of standard parts
	Cost	9	Cardboard is easily available and making the machine cost efficient
3	Safety	9	The machine is automated and does not cause any harm to the object or the user in anyway.
	Ease of use	7	Since the machine is automated, human intervention is minimum thereby making the machine easy to use.
	Portability	9	The machine is light in weight and smaller in size, which makes it easy to be carried from one place to another.
	Use of standard parts	8	There is use of standard and efficient electric components (motor).
	Cost	6	Since the used parts are costly and are not easily available.
4	Safety	7	The machine is digital and pre programmed and requires no much human work.
	Ease of use	6	Requires manual work to attach the template on the object and to adjust the object in the machine.
	Portability	8	The machine is compact and easy to carry anywhere.
	Use of standard parts	7	Use of heater which produces heat through electricity.
	Cost	7	Since the machine is digital and uses electric heater, so the machine is expensive.