Design for X (DFX) Design for Manufacture. 1/2 Oz., 90 PSI. (X is a Variable Name)

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Bartholomew Sparks
5 years ago
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2 Phases of Design ) Customer Requirements 2) Specification Development 3) Conceptual Design 4) Detail Design 5) Specification of Production 6) Manufacture 7) Recycle

3 Design for X (DFX) (X is a Variable Name) Design for Manufacture /2 Oz., 90 PSI

4 Manufacturing Process (

5 AL Mill Roller Crane

6 Design for Environment Design for X (DFX)

7 Design for X (DFX) Design for Maintenance Design for Safety

8 Design for X (DFX) Design for Assembly

9 Design for Assembly Methods consists of a design review by Design and development personnel Production personnel The technique imposes Discipline Objectiveness

10 Aspects of Design for Assembly DFA is applicable to Products consisting of parts Mainly for mechanical parts (not electronic circuits) Dimensions lie between those of watches and cars Requires -2 days to perform for a product Can be performed in the various stages in the design process and repeated

11 Assembly Operations Storing Positioning Orientating, Aligning Handling Identifying, Picking-Up, Moving Joining Adjusting Securing Inspecting

12 Assembly Standardization Standardization of operations Use of existing equipment and tools Use of standard tools

13 Number & Sequence of Operations Number of assembly operations Sequence (preassembly, parallel assembly)

14 Automated Assembly Difficulty/Cost of automation Freedom from possible assembly errors Avoidance of damage to components

15 Assembly Workers Avoid special training of assembly staff Maintain safe working conditions Observe ergonomic standards

16 Questions Raised During DFA Is it possible to eliminate part of the process? Can the product be assembled if the part is integrated with another part? What is the cost to correctly orient and position a part? What does it cost to complete the assembly of the part?

17 Questions Raised During DFA During product operation, does the part move relative to other parts? Consider only gross motions Small motions can be accomplished by deformation (such as elastic hinges). Must the part be of a different material than other parts?

18 Pneumatic Piston Assembly - Screw (2) (steel) 2 - Cover (steel) 3 - Spring (steel) 4 - Piston stop (nylon) 5 - Piston (aluminum) 6 - Main block (plastic)

19 Design for Assembly Worksheet Part I.D. Number Number of times the operation is carried out consecutively Two-digit manual handling code Manual handling time per part Two-manual insertion code Manual insertion time per part Operation time (sec) (2)*[(4) + (6)] Operation cost ( ) 0.4 * (7) Figures for theoretical minimum parts Estimation Name of Assembly TM = Total manual assembly time CM = Total cost of manual assembly NM = Theoretical minimum number of parts TM CM NM

20 Pneumatic Piston Assembly - Screw (2) (steel) 2 - Cover (steel) 3 - Spring (steel) 4 - Piston stop (nylon) 5 - Piston (aluminum) 6 - Main block (plastic)

21 Worksheet for Pneumatic Piston Part I.D. Number Number of times the operation is carried out consecutively 2 Two-digit manual handling code Manual handling time per part Two-digit manual insertion code Manual insertion time per part Operation time (sec) (2)*[(4) + (6)] Operation cost ( ) 0.4 * (7) Figures for theoretical minimum parts Estimation 0 0 Name of Assembly Pneumatic Piston Main Block Piston Piston Stop Spring Cover Screw TM = Total manual assembly time CM = Total cost of manual assembly NM = Theoretical minimum number of parts TM CM NM 3 * N M d e s i g n e f f i c i e n c y = = T M 0.29 Minimum Operation Time

22 Redesigned Pneumatic Piston - Snap on cover and stop (plastic) 2 - Spring (steel) 3 - Piston (aluminum) 4 - Main block (plastic)

24 Worksheet for Redesigned Piston Part I.D. Number Number of times the operation is carried out consecutively Two-digit manual handling code Manual handling time per part Two-digit manual insertion code Manual insertion time per part Operation time (sec) (2)*[(4) + (6)] Operation cost ( ) 0.4 * (7) Figures for theoretical minimum parts Estimation Name of Assembly Pneumatic Piston (re-design) Main Block Piston Spring Cover & Snap TM = Total manual assembly time CM = Total cost of manual assembly NM = Theoretical minimum number of parts TM CM NM 3 * N M d e s i g n e f f i c i e n c y = = T M 0.90

25 Design for Automated Assembly (Concepts) Layered design Clamshell base Sequential assembly Uni-directional Self-alignment Chamfer/countersink Posts/locating stops Combine detail parts Screws & washers Plastic moldings Castings Symmetry Direct drive systems Helical or gear vs. Belt/pulley Common fasteners Minimize screws Snap fasteners Minimize springs Molded Compression coil Extensive coil Minimize cables Integrated packaging Solid connectors

26 Example of Layered Assembly Snaps Snaps

27 Compliance and Assembly Avoid Better Best No Chamfers Bottom Part Chamfered Bottom Part Chamfered Both Parts Chamfered

28 Self Alignment of Parts This part could be oriented in any direction These parts can be oriented only one way Hole to accept swaged part Hole to accept notched part D shaped hole

29 Nesting of Parts This part could be placed in any orientation and not be secured This part has a nest to orient and help it secure

30 Nonfunctional External Feature for Orientation This slot would be hard to detect Pin to help orient slot Chamfer to help orient slot

31 Symmetry Orientation Required Preferred

32 Tangling These parts can tangle easily The same parts redesigned, will not tangle

33 Tangling (continued) Parts that interconnect will not feed Springs with open loops will tangle A fillet will keep the parts from interconnecting Springs with closed loops will not tangle

34 Methods to Avoid Jams ( of 2) This results in shingling Direction of Flow Base causes leading edge to be lower than trailing edge A nonfunctional corner can eliminate this problem

35 Methods to Avoid Jams (2 of 2) Mating surfaces with sharp edges can cause jams Rounded corners can prevent jams A groove can prevent jams by centering the part

36 Substitutes Avoid designs that require fasteners for Fasteners Design parts that snap together

37 Joining Moving Parts without Fasteners C-Clip Snaps Chamfered Surface

38 Fasteners Preferred: Have flat vertical sides for vacuum pickup Socket Head Fillister Head Hex Head Round Side Avoid Slant Side Round Head Flat Head

39 Cables and Connectors Example of a slave circuit board Avoid: Components that are connected with cables to circuit board Preferred: Components that are plugged on a slave circuit board

40 Cables and Connectors Example of a secured cable If the use of a cable cannot be avoided. Have the cable plugged into a dummy connector to locate the cable end. Then a robot can locate the connector and plug it in.

41 Avoid: Three motions required for insertion Slot Motion and Preferred: Only one motion required Design Snaps

42 Design for ME20 Assembly Keep it Simple Easy Access to All Parts (So they can be replaced) Easy to Set Triggers Start Assembly Now

Lecture #8. Design for Manufacturing DfM. ME 2110: Creative Decisions and Design

Lecture #8. Design for Manufacturing DfM. ME 2110: Creative Decisions and Design Lecture #8 Design for Manufacturing DfM Phases of Design ) Customer Requirements 2) Specification Development 3) Conceptual Design 4) Detail Design 5) Specification of Production 6) Manufacture 7) Recycle