University of Puerto Rico Mechanical Engineering Department Ha-S Hide-Away Shank Screwdriver...

University of Puerto RicoMechanical Engineering Department

Ha-S Hide-Away Shank Screwdriver

Lynnette M. Méndez-Galarza

Jean Carlos Rivera

Mario Rosario Adorno

Reinaldo Santiago Bermúdez

Vijay K. Goyal, PhD -- Faculty AdvisorCourse:

Computer Aided Design

Problem description

• Adult accidents:Dropping the toolMisplace the tool

• Children’s curiosity:Poking body partsPlaying with power

outlets • Compact:

Difficult PortabilityAwkward Storage

Picture: http://clerccenter.gallaudet.edu/AcademicTeams/EC-ed/2001-2002/electric/images/Screwdriver%20EN.jpg

http://clerccenter.gallaudet.edu/AcademicTeams/EC-ed/2001-2002/electric/images/Screwdriver%20EN.jpg

Objectives

• Minimize risk of an accident with a screwdriver.

• Child-proof

• Compact the screwdriver for easy storage and portability

Possible Solutions

First idea - Hide-Away Gear Shank

Possible Solutions

Second idea - Hide-Away Antenna Type Shank

Possible Solutions

Third idea - Hide-Away Shank

Idea Selection

Criteria Score(0-10)

DatumScore

Idea IScore

Idea IIScore

Idea IIIScore

Weight 2 0 -1 -2 -1

Size 4 0 2 2 2Safety 10 0 1 1 2Versatility 7 0 2 2 2Appearance 3 0 1 2 2Additional Features 3 0 1 1 2

Production Cost 3 0 -2 -2 -2

TOTAL 32 0 4 4 7

Total Positive N/A 0 7 8 10

Total Negative N/A 0 -3 -4 -3

Weighted Total N/A 0 30 31 46

*Datum-Regular Screwdriver

Selected Design Specifications

BITBOX

Selected Design Specifications

Optimization Analysis

Minimize weight

cc ggxxggxxxf /*)75(.*/)1(*)(min 22

1222

11

• Everything with a subscript “1” refers to the shank properties

• Everything with a subscript “2” refers to the handle properties


• Method of Lagrange MultipliersConstraints:

LaGrange Equation:

0*5.1

32)(

31

1 yx

Txg

0

*2)(

21

2 yx

P

A

Pxg

03)( 23 Xxg

)5()3(29700979.3

29700729.25

*)75(.142.0*)1(911.0)(x, 242321

231

122

12

12

XX

xxxxxx

05)( 24 Xxg


)5(**

)3(**

29700979.3

**

29700729.25

**

0)75(.1442.0*911.0

0958.719.77

*)75(.284.0)1(*822.1

2444

2333

21

222

31

111

432

12

12

31

241

121211

Xg

Xg

Xg

Xg

XXX

XXXXXX

X


0

0.071

0

0

3

0.142

4

3

2

1

2

1

X

X

!...02)(

!...00)(

!...029502)(

!...020714)(

GOOD! :Defined...194216.0)(

*4

*3

*2

*1

*

GoodXg

GoodXg

GoodXg

GoodXg

Xf

Solution: K-T Conditions

ANSYS Analysis

• Preprocessor

• Real Constants

• Material Properties

• Modeling

• Meshing

• Solution

ANSYS Analysis

Cost Analysis

Part / process PricePolymer 8’ $65.04Stainless Steel Rod (303) - 6’-5/32”R $7.48Stainless Steel Tube (304) - 12”-5/16”R $4.59Bits (16pzs) $3.00Bitbox $5.00Miscellaneous $5.00Turning @ $30/hr $0.50Total of one design $90.61

Cost Analysis

Part / process PricePolymer – 3” $2.00Stainless Steel Rod (303) - 6’-5/32”R $0.30Stainless Steel Tube (304) - 12”-5/16”R $0.80Bits (16pzs) $3.00Bitbox $5.00Miscellaneous $5.00Turning @ $30/hr $0.50Total per screwdriver $16.60

Conclusions

•Optimum value• 3” long• 0.15” radius

•Stresses do not exceed safe limits•Easy storage•Child-proof

Peace of mind now comes in a small, practical and attractive

package: the Ha-S.

(KISS)

Questions or Comments

University of Puerto Rico Mechanical Engineering Department Ha-S Hide-Away Shank Screwdriver...

Documents

Transcript of University of Puerto Rico Mechanical Engineering Department Ha-S Hide-Away Shank Screwdriver...