1. Design for Analysis Computer Integrated Manufacturing
Airplane Propeller
Design for Analysis
Computer Integrated Manufacturing

2. Objective
Apply DFA guidelines in order to improve the design efficiency by :
Reducing the part count
Reducing manual handling and insertion times
Improving current part design

3. Airplane Propeller Main Function Parts description
Provide repulsive force by blades rotation which have variable pitch
Parts description
14 main parts excluding fasteners
Exploded view

5. DFA Analysis Initial DFA Analysis Part # # Of operations Manual code
Handling time
Insertion code
Insertion time
Total time
Operation cost
Theo min parts
Part name 1 99 9 00
1.5
10.5
0.04
motor 2 02
2.5
11.5
0.05
tail cone 3 4 05
1.84 08
6.5
33.36
0.13
shaft seal 01
1.13 51
10.13
drive pin 5 31 14
0.06
clutch plate 6
inner hub 7 97 30 21
0.08
blade 8
1.43 18
10.43
clutch support washer
93.87
0.38
clutch spring washer 10
clutch washer 11
0.03
yoke 12 39
9.5
yoke screw 13 98
outer hub
pitch adj knob
262.72
1.05 26
Total
Design Efficiency

6. Applying DFA guidelines Reducing part count
9 clutch Spring washers
Serve as a shock absorbent
Close ended spring

7. Applying DFA guidelines Reducing part count
Combine Outer hub & Pitch adjustment knob in one part

8. Applying DFA guidelines Insertion
Re-design of yoke screw; addition of cone point end to facilitate alignment
Addition of mating hole at the bottom of knob

9. Applying DFA guidelines Part Symmetry
Improving alpha symmetry for Yoke to minimize handling time

10. outer hub and adjustment knob
Improved DFA Analysis
Part #
# Of operations
Manual code
Handling time
Insertion code
Insertion time
Total time
Operation cost
Theo min parts
Part name 1 99 9 00
1.5
10.5
0.04
motor 2 02
2.5
11.5
0.05
tail cone 3 4 05
1.84 08
6.5
33.36
0.13
shaft seal 01
1.13 51
10.13
drive pin 5 31 14
0.06
clutch plate 6
inner hub 7 97 30 21
0.08
blade 8
1.43 18
10.43
clutch support washer
2.63
0.01
spring 10
clutch washer 11
3.13
yoke 12 38
7.5
0.03
yoke screw 13 06
5.5
outer hub and adjustment knob
0.00
Part eliminated
159.11
0.64
Total
Design Efficiency

11. Conclusion Almost 40% Improvement in Total Assembly Time
39% reduction in Operation Cost
4% Increase in Design Efficiency
Before
After
Total Time
263 Seconds
159 Seconds
Operation Cost
1.05
0.64
Design Efficiency