Design For Manufacturing and Assembly.

1. "DESIGN FOR MANUFACTURING AND
ASSEMBLY"
1DFMA

2. 1.DESIGN FOR MACHINABILITY
2.DESIGN FOR ECONOMY
3.DESIGN FOR CLAMPABILITY
4.DESIGN FOR ACCESSIBILITY
TOPICS:
5.DESIGN FOR ASSEMBLY
DFMA 2

3. What is Design for Machinability ?
DESIGN FOR MACHINABILITY:
“It is design of part or
product which is
considered the ease with
which part or product
can be machined“.
DFMA 3

4. DESIGN FOR MACHINABILITY[2]:
STANDAR-
DIZATION ASSEMBLY
CHOIS OF
WORK
MATERIAL
ACCURACY
AND
SURFACE
FINISH
Design for
Machinability
SIZE AND
SHAPE OF
WORK
MATERIAL
DFMA 4

5. DESIGN FOR MACHINABILITY[2]:
DESIGN GUIDLINES:
1) STANDARDIZATION:
 Utilize standard component.
 Utilize standard pre-shaped
workpiece .
 Employ standard machined
features.
DFMA 5

6. DESIGN FOR MACHINABILITY[2]:
DESIGN GUIDLINES:
2) CHOICE OF MATERIAL:
 Choose material with
minimum cost.
 Utilize raw material in the
standard form supplier.
DFMA 6

7. DESIGN FOR MACHINABILITY[2]:
DESIGN GUIDLINES:
3) SHAPE AND SIZE OF MATERIAL(General):
 It can be machined on one machine tool.
 workpiece should be gripped so that it can be rigid to
withstand machining force.
 The tool, toolholder, work and workholding device would not
interfere with one another.
 Auxiliary holes or bores should cylindrical and with standard
L/D ratio.
DFMA 7

8. DESIGN FOR MACHINABILITY:
DESIGN GUIDLINES:
DFMA 8

9. DESIGN FOR MACHINABILITY[2]:
DESIGN GUIDLINES:
3) SHAPE AND SIZE OF MATERIAL(Rotational):
 Cylindrical surface should be concentric and plane surface
are normal to the component axis.
 Avoid internal features for long component.
 Avoid very large or very small L/D ratio.
DFMA 9

10. DESIGN FOR MACHINABILITY[2]:
DESIGN GUIDLINES:
4) ASSEMBLY:
 Ensure that each operating machined surface on a component
has a corresponding machined surface on mating component.
 Ensure that internal corners do not interfere with a
corresponding external corner on the mating component.
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11. DESIGN FOR MACHINABILITY:
DESIGN GUIDLINES:
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12. DESIGN FOR MACHINABILITY[2]:
DESIGN GUIDLINES:
5) ACCURACY AND SURFACE FINISH:
 Specify the widest tolerance and roughness surface that
would give the required performance for operating surface.
DFMA 12

13. What is Design for Economy ?
DESIGN FOR ECONOMY:
“Design for Economy is the
orientation of the designing
process to reduce life cycle
cost while satisfying customers
demand“.
DFMA 13

14. DESIGN FOR ECONOMY[6]:
DESIGN FOR
ECONOMY
DESIGN FOR COST DESIGN TO COST
 Design for cost is the continues
use of engineering process and
technology to reduce life cycle
cost.
 Engineering driven process.
 Design to cost is the iterative
redesign of project until the
content of project meets a given
budget.
 Iterative by nature.
 Management driven process.
DFMA 14

15. DESIGN FOR ECONOMY:
What internal organization has the most influence over
price, quality and cycle time!!!
30-40%
60-70%
0%0%
Designing = 60-70%
Manufacturing = 30-40%
DFMA 15

16. DESIGN FOR ECONOMY[6]:
METHOD FOR DESIGNING FOR COST
1)VALUE ENGINEERING:
 Uses function cost analysis to reduce cost.
2)COST TABLE
 Uses function cost analysis to reduce cost.
3)RESPONCE SURFACE METHODOLOGY:
 Collection of mathematical and statical techniques that are
useful for the modeling and analysis of problem to reduce
cost.
DFMA 16

17. DESIGN FOR ECONOMY:
DFMA 17

18. DESIGN FOR ECONOMY[6]:
4)TAGUCHI METHOD:
 Improve the implementation of Total Quality Control to
reduce cost.
5)MULTIDISCIPLINARY OPTIMIXATION:
 it is optimization technique to reduce cost.
6)KAIZEN:
 Improvement in quality of product to reduce cost.
7)JUST IN TIME:
 Cost is reduced by reducing inventory.
METHOD FOR DESIGNING FOR COST
DFMA 18

19. What is Clampability ?
DESIGN FOR CLAMPABILITY[4]:
"Capability of
being clamped"
DFMA 19

20. DESIGN FOR CLAMPABILITY[4]:
What is Design for Clampability ?
“It is defined as the ease
with which part or product
can be clamped with other
part easily“.
DFMA 20

21. DESIGN FOR CLAMPABILITY[5]:
DESIGN GUIDLINES:
1) Self fastening
2) Self locking
DFMA 21

22. DESIGN FOR CLAMPABILITY[5]:
DESIGN GUIDLINES:
3) Modular design
4) Using standard part
5) Symmetric parts
6) Extra features for clamping
DFMA 22

23. DESIGN FOR CLAMPABILITY:
Example:
 The workpiece to be machine on lathe machine should
cylindrical shape, so that it can easily clamped on chuck.
DFMA 23

24. What is Design for Accessibility ?
DESIGN FOR ACCESSIBILITY[5]:
“Design for accessibility is
a process by which
products are design with
ease of accessibility in
mind“.
DFMA 24

25. Example:
DESIGN FOR ACCESSIBILITY:
DFMA 25

26. DESIGN GUIDLINES:
DESIGN FOR ACCESSIBILITY[5]:
1) Indicate orientation
2) Part do not tangle or stick to each other.
3) Prevent nesting
4) Insertion from top is preferred.
5) Use standard part
DFMA 26

27. DESIGN GUIDLINES:
DESIGN FOR ACCESSIBILITY[5]:
5) Deep channels should be sufficiently wide to provide access.
6) Proper spacing
7) Prevent obstracted access.
8) Provide adequate access and visibility.
DFMA 27

28. DESIGN GUIDLINES:
DESIGN FOR ACCESSIBILITY[2]:
DFMA 28

29. DESIGN FOR ASSEMBLY[2]:
What is Design for Assembly ?
“Design for Assembly is
the method of design of the
product for ease of
assembly“.
DFMA 29

30. DESIGN FOR ASSEMBLY:
Example:
DFMA 30

31. DESIGN FOR ASSEMBLY:
DFAANALYSIS WORKSHEET:
DFMA 31

32. DESIGN FOR ASSEMBLY[2]:
1) Use minimum part.
2) Design part with self-locating features.
3) Design part with self-fastning features.
4) Use modular design.
5) Use base part to locate other parts.
DESIGN GUIDLINES:
DFMA 32

33. DESIGN FOR ASSEMBLY[2]:
DESIGN GUIDLINES:
6) Design part for retrieval, handling and insertion.
7) Use symmetric component.
8) Use top-down assembly.
DFMA 33

34. DESIGN FOR ASSEMBLY:
Old Design New redesign
Example of redesign:
DFMA 34

35. DESIGN FOR ASSEMBLY[2],[5]:
DFA Process:
STEP-1
Product information:
1)Functional requirement
2)Function analysis
3)Identify parts that can be standardized
4)Determine part count efficiencies.
STEP-2
Determine your practical part count.
STEP-3
Identify quality(mistake proofing) opportunities.
DFMA 35

36. DESIGN FOR ASSEMBLY[2],[5]:
STEP-6
Identify opportunities to reduce secondary operations.
STEP-7
Analyze data for new design.
STEP-5
Identify insertion (locate and secure) opportunities.
STEP-4
Identify handling (grasp and orientation) opportunities.
DFA Process:
DFMA 36

37. DESIGN FOR ASSEMBLY:
New Redesign for DFA:
DFMA 37

38. REFRENCE:
[1] Assembly automation & Product Design.G.Boothroyd, Marcell dekker, Inc.1992.
[2] Product Design for Manufacturing & Assembly.G.Boothroyd and
P.Dewhurst.Inc.1989. Marcell Dekker.Inc.1994.
[3] Engineering Design. George E.Dieter, Linda C. Schmidt.
[4] https://en.m.wikipedia.org/wiki/Design_for_assembly.
[5] National Programme On Technology Enhanced Learning. nptl.ac.in
[6] Design for cost (Article).Edwin B.Dean, R.Unal (1991).
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