Presentation is loading. Please wait.

Presentation is loading. Please wait.

1 2.875 Mechanical Assembly and Its Role in Product Design Pencil Sharpener Presentation#1 November 14, 2001 Hernan Joglar John Sharkey.

Similar presentations


Presentation on theme: "1 2.875 Mechanical Assembly and Its Role in Product Design Pencil Sharpener Presentation#1 November 14, 2001 Hernan Joglar John Sharkey."— Presentation transcript:

1 Mechanical Assembly and Its Role in Product Design Pencil Sharpener Presentation#1 November 14, 2001 Hernan Joglar John Sharkey

2 2 Presentation Contents Product Description Company Background CAD Exploded view Parts and Material List Photo of Product Disassembly Product Structural Decomposition Major Sub-Assemblies Critical Mates and Clearances Gearbox Key Characteristics and Datum Flow Chain Assembly liaison diagram Assembly Time Analysis Example Assembly Process Fixtures and Special Tooling Potential Problems and Risks Suggested Assembly Improvements Backups –DFA Gross Motions- Product Structural Decomposition –DFA Fine Motions- Part Liaisons and Mates –Related Product Line

3 3 Battery Operated Pencil Sharpener: Model #16750 (black) –Referred to as a “razor spiral cutter” model –Operation activated by axial force of pencil insertion –Safety lockout feature prevents operation without receptacle –Features 1 year warranty No replaceable parts, Hunt simply replaces defective units Product Assembly Specifications: –29 identified parts, comprising 7 sub-assemblies –35 assembly features and liaisons –Physical dimensions: 4.75” x 3.00” x 2.25” at 6.1 ounce weight Popular with graphic artists and designers –provides clean, sharp pencil points for a wide range of pencil types, including composite pencils Approximately 250,000 units sold last year –Distributed through all major office supply retail stores Staples, Office Depot, Wal-Mart, Target, etc –Typically sells for around $5.00 Boston Stapler Product Description

4 4 Hunt Manufacturing Corporation Founded in 1899 by George Bartol Went public in 1982 after a series of expansions and acquisitions. Corporate headquarters in Statesville, NC Donald L. Thompson became president and CEO in 1996 Product design center located in Statesville, NC Outsources most manufacturing within the United States Boston Series of pencil sharpeners manufactured in China 1300 employees nationwide Sales revenue of $286M in 2000, 1.6% increase over 1999 Main product lines is graphics equipment and office supplies A global leader in the pencil-sharpener market Boston family of pencil sharpeners and staplers accounts for 40% of company sales Other significant products lines include: Exacto razor blades Conte crayons and pastels Bienfang paper, painter markers, foam boards and laminates Seal imaging equipment

5 5 CAD Exploded View [ Model developed using Autodesk Inventer Version 3.0 ]

6 6 Parts and Material List

7 7 Photo of Product Disassembly

8 8 Complete Assembly Battery Compartment Base Motor Gearbox Base screwsPencil guide Bat. Comp. screws Shavings receptacle Sharpener case Bat. Comp. housing Bat. Comp. contacts Bat. install. guide Sharpener base Rubber foot Battery Comp. cover Contacts battery Comp. cover Battery Comp. cover Rubber foot Black wire Gearbox housing Output gear Intermediate gear Driven gear Gearbox cover screw Electric motor Safety lever Lubrication Cutter Unit Gearbox cover Blade nut and bolt Blade Blade holder Gearbox cover contacts Red wire Blue wire General Assembly Sub- Assembly Part Product Structural Decomposition

9 9 Major Sub-Assemblies Gearbox housing Motor rim Gearbox Cover Motor Output gear Intermediate gear Driven gear Motor Gearbox Sub-Assembly Cutter Unit Sub-Assembly Battery Compartment Sub-Assembly Mating features Electric in-out contacts Red and black electric wires Electric contact rivets Input contact Intermediate contact Edge Output contact Safety lever pin Gearbox cover Sub-Assembly Blade Blade holder Nut Bolt

10 10 Critical Mate and Clearance Ratio #1 Shaver Receptacle to Shaver Case Slots Rims

11 11 Critical Mate and Clearance Ratio #2 Base to Sharpener Case Edge Interface Holes Slot along edge Rim along edge Pegs Rim Sliding surfaces Slot Note: Clearance ratio requires Gearbox and battery compartment sub-assemblies to be inserted.

12 12 Slots Rim and snap fit Critical Mate and Clearance Ratio #3 Rims Slot

13 13 Gearbox DFC and Key Characteristics Gear housing cover 2Driven gear block 3Intermediate gear block 4Output gear block 5Top lateral stopping peg 6Top central stopping peg 7Motor Location pegs 8Gear housing 9Motor gear 1Driven gear input pinion 1Driven gear output pinion 1Driven gear stand 1 Driven gear pin 1 Intermediate gear input pinion 1Intermediate gear output pinion 1Intermediate gear stand and hole 1Intermediate gear pin 1Output gear 1Output gear stand 2Bottom lateral stopping peg 2Bottom central stopping peg 2Top part of motor compartment in gear housing 2Hole in gear housing for motor location 2Motor Z X

14 14

15 15 Pitch circle of driven gear Pitch circle of intermediate gear Bottom Stopping pegs Rim Gears top surfaces Driven gear pin Driven gear stand Intermediate gear pin Intermediate gear stand Tangency KC Intermediate gear Gear hole Bottom surface Driven gear Gear hole Bottom surface Pitch circle driven gear output pinion Gear Housing Top surface Top Stopping pegs and contact end Rim Edges Bottom stopping pegs and contact surface Driven gear block Intermediate gear block Top surface Co-planarity KC Bottom surface input pinion Top surface driven gear input pinion Pitch circle input pinion Gear pins Gear stands Simplified Gearbox DFC: Driven to Intermediate Gear Gear Housing cover

16 16 Pencil Sharpener Liaison Diagram and Fasteners Classification c6 p4p7 c3 p5 c22 p6 c2p9 c23 c31 p10 p8 c1 p11 c24 c25 p12 p13 c26 p14 p20 c15 p2 p21 c13c18 c17 c14 p29 c20 c12 p27 p28 c21 c4 c5 p15 c7 c9 c29 c30 p18 p17 p16 c28 c27 c10 c19 c16 c8 p26c32p23 c34 c35 p24 p25 c11 c33 C37 C36 c38 Permanent Liaisons Rivets Adhesive Soldering Liaisons Using Threaded Features Screws Nut & Bolt Other mates

17 17 Throughput requirement based on production volume –250, workdays/year = 1000 units/day – hours/day = 125 units/hour = 2.08 mins/unit Assembly time per Boothroyd Handling and Insertion Times –Handling Time per unit= (sec/unit) –Location Time per unit= (sec/unit) –Reversible Fastening Time per unit= (sec/unit) –Irreversible Fastening Time per unit= (sec/unit) –Total predicted assembly time= (sec/unit) Note: does not include inspection and test time Measured Handling, Location and Reversible Fastening Times –Test#1 309 sec- Test#4 169 sec –Test#2222 sec- Test#5 153 sec –Test#3198 sec Assembly Efficiency –Three “un-necessary parts: Sharpener case, paper guide, and pencil guide – (sec) Assembly Time Analysis

18 18 Example Assembly Process SA 7 Cutter Unit Assy SA 7 Cutter Unit Inspect SA6 Gearbox Cover Assy SA 6 Gearbox Cover Inspect SA5 Battery Comp. Assy SA 5 Battery Comp. Inspect SA3 Battery Cover Assy SA 3 Battery Cover Inspect SA5a Gearbox Assy SA5a Gearbox Solder SA5a Gearbox Test SA5 Motor/Gearbox Assy SA2 Base Assy SA1 Final Assy SA1 Final Inspect Package & Ship sec sec sec sec 5 sec 33.5 sec sec 20 sec 30 sec Note: Test, inspection and packaging times are SWAGS

19 19 Fixtures and Special Tooling Fixtures Riveting fixture. or special tooling, for battery compartment Riveting fixture, or special tooling, for gearbox cover Bending fixture for gearbox cover electrical contacts Bending fixture for battery cover electrical contacts Bending fixture for battery compartment electrical contacts (nice to have) Soldering station and fixture for electric motor (black and blue leads) Soldering station and fixture for battery compartment (black and red leads) Standard Tools and Special Tooling Heat stake tooling for battery compartment electrical contacts Magnetic Phillips head screwdriver (4” length) for battery compartment screw Small wrench, or pliers, for blade screw and nut Wire strippers (22 gage) Wire tinning and pre-form bending Soldering station for gearbox cover Electrical test station for operation of motor/gearbox sub-assembly Lubrication dispenser gun

20 20 Potential Problems and Risk Areas DescriptionProbabilityImpact Personnel injury from razor blade MedHigh Reversed motor polarity wiring (black on +) HighHigh Reversed battery compartment wiring (red on right) HighHigh Solder joint or wire breakage during gearbox insertion LowHigh Solder joint or wire breakage during motor insertion LowHigh Motor pinion clearance thru gearbox hole HighMed Loss of motor location during final assembly HighMed Improper location of battery compartment on gearbox MedMed Part damage from shaver receptacle insertion (snap fit) MedMed

21 21 Suggested Design Improvements DescriptionImpact Reversed motor polarity wiring (black on +) - Use wire connector instead of solder jointMed Reversed battery compartment wiring (red on right) - Imprint wiring polarity on battery compartment injection moldHigh Solder joint or wire breakage during gearbox insertion - Use wire connector instead of solder joint Med Solder joint or wire breakage during motor insertion - Use wire connector instead of solder joint Med Motor pinion clearance thru gearbox hole - Reduce and control gearbox manufacturing varianceMed Loss of motor location during final assembly - Include snap/fit feature between battery compartment and gearboxHigh Improper location of battery compartment on gearbox - Use wire connectors instead of solder joint Med Part damage during shaver receptacle insertion (snap fit) - Training, coupled with control of manufacturing variationsLow

22 22 Backups Part Handling: Gross Motion ( 2 slides) Part Insertion: Fine Motions ( 2 slides) Part Liaisons and Mates Related Product Lines Product Structural Decomposition

23 23 Part Handling: Gross Motion

24 24 Part Handling: Gross Motion (con’t)

25 25 Part Insertion: Fine Motion

26 26 Part Insertion: Fine Motion (con’t)

27 27 Part Handling: Gross Motion (con’t)

28 28 Part Liaisons and Mates in Pencil Sharpener

29 29 Part Liaisons and Mates in Pencil Sharpener (cont.)

30 30 Related Product Line Boston Powerhouse Electric Sharpener Item # , Style # $21.99 each This new powerful, heavy-duty commercial grade sharpener uses X-Acto precision steel cutters and a Pencil- Saver feature to sharpen to a perfect point. Features auto- reset and built-in pencil holder. Boston Electric Auto-Reset Pencil Sharpener Item # , Style # $12.99 each New exclusive design offers modern styling with proven Boston quality, Auto-Reset thermal overload, solid steel cutter and nonskid rubber feet. Boston Battery Pencil Sharpener Item # , Style # $5.99 each Sleek, compact design with powerful razor blade sharpening mechanism. Safety features-Auto on-off switch; sharpener doesn't operate if receptacle isn't secured. Runs on 4 AA batteries (not included). Boston Electric Standup Pencil Sharpener Item # , Style # $19.99 each Features X-ACTO precision cutters for longer life. Unique stand up design stands out on your desk. 2 year warranty.

31 31 Product Structural Decomposition p12 sa5 sa7sa6 sa4 sa3 p3p4p2sa2 p6p5 p15p16p17p18p19p20p21 p23 p24p25p27p28 p22 p26p29 p8p9p10 p1 p14 sa1 p7 p11 p13


Download ppt "1 2.875 Mechanical Assembly and Its Role in Product Design Pencil Sharpener Presentation#1 November 14, 2001 Hernan Joglar John Sharkey."

Similar presentations


Ads by Google