polished recommendation report

TCM 359 Polished Recommendation Report Joe Legan

TCM 359 Recommendation Report

4/10/16

Joe Legan


Executive Summary

The purpose of this report is to recommend one of two designs of a lug wrench for use with an all-terrain vehicle (ATV). The criteria used are cost, weight, strength and dimensions. Of the four criteria, cost and strength are the most important. Design A has an advantage of requiring fewer processes to manufacture as documented in the Dimensions section below. Design B has advantages in all three other criteria, especially cost and strength. For this reason it is recommended that Design B be put into production as it meets all the needs of the ATV manufacturer.


Introduction

The purpose of this report is to recommend one of two different designs of a lug wrench for use with an all-terrain vehicle (ATV). The goal of the design is to create a low cost and light weight design that is suitable for manufacturing. Design A is a traditional style of lug wrench and can be seen in the Appendix as Figure 1. Design B is a T-handle style that can be seen in the Appendix as Figure 2. There are two possible solutions between the designs. The first solution is an extended analysis of Design A followed by a probable change in dimensions to the tool. The second solution is to proceed with lifecycle testing of Design B in preparation for production.

Problem

There are two possible designs for the lug wrench, only one can produced.

Scope

The four criteria provided for the design were that it had to be low cost, lightweight, be able to withstand 70 pound applied force (strength), have a 3 inch stub shaft and a 12 inch lever arm (dimensions).

Discussion

Cost

Design A has a mass of 0.61 kg and at a rate of 0.614USD/kg, each unit would cost $0.37 in material to produce. Design B has a mass of 0.41 kg and at the same rate would cost $0.25 for each unit produced in material cost. This is a savings of $120.00 per 1,000 units produced. The exact mass properties can be seen in the appendix. Cost is of some concern as usual but it is not the most critical criteria. This criteria has a moderate weighting.

Weight

Design A has a weight of 1.34 pounds while Design B has a weight of 0.91 pounds. Design B has a weight savings of just under 68%. Weight of the tool is considered as it could potentially detract from the performance of the ATV. No special weighting is required for this criteria.


Strength

Analysis reveals that Design A will fail under the applied 70 pound force. Design B will not fail. Design A has a Factor of Safety (FOS) of 0.91 while Design B has a FOS of 10 at the lowest point (Legan/MET 310, 2016, p. 5). As the manufacturer of the ATV strives to produce a quality product, they have great concern that the tools they include with their product be of sufficient strength to perform the task required. This criteria is heavily weighted.

Dimensions

Both designs have the required dimensions of a 12 inch lever arm and a 3 inch stub shaft. However Design B has a smaller surface area by 67% making packaging for it easier within the confines of the ATV. Design A can be cast as a single piece requiring no special machining. Design B can be cast as one piece or welded from two independent pieces. No special weighting is required for this criteria.

Table of Criterion Advantage by Design

Criterion Design A Design BCost ($/unit) $0.34 $0.25Weight (lbs) 1.34 0.91

Strength (FOS) 0.91 10.0+Dimensions

(Surface area sq. inches) 33.86 22.75

Conclusion

Summary

This study evaluated two designs for a lug wrench for use with an all-terrain vehicle based upon the criteria of cost, weight, strength and dimensions. Design B has advantages in both cost and strength, the heavily weighted criteria. Design A can be manufactured in few processes than Design B.


Conclusion

Design B has more advantages than A in all respects save the amount of steps to manufacture. Given that tool must meet the criteria of the customer while creating a profit for us the manufacturer, it appears that Design B will be more suitable design with its advantages over Design A Due to these advantages it is recommended that Design B be put into process for lifecycle testing in preparation for production.


References

Legan/MET 310, J. F. (2016). Simulation of modified lug wrench (1). Indianapolis, IN:

SolidWorks Simulation.


Appendix

Figure 1


Figure 2

Design A Mass PropertiesMass properties of Project 1 Final Attempt Configuration: Default Coordinate system: -- default --

Density = 0.13 kilograms per cubic inch

Mass = 0.61 kilograms

Volume = 4.76 cubic inches

Surface area = 33.86 square inches

Center of mass: (inches)X = 4.65


Y = 0.51Z = 0.00

Principal axes of inertia and principal moments of inertia: (kilograms * square inches)Taken at the center of mass.

Ix = ( 0.99, -0.16, 0.00) Px = 0.40 Iy = ( 0.16, 0.99, 0.00) Py = 9.70 Iz = ( 0.00, 0.00, 1.00) Pz = 10.07

Moments of inertia: ( kilograms * square inches )Taken at the center of mass and aligned with the output coordinate system.

Lxx = 0.63 Lxy = -1.43 Lxz = 0.00Lyx = -1.43 Lyy = 9.47 Lyz = 0.00Lzx = 0.00 Lzy = 0.00 Lzz = 10.07

Moments of inertia: ( kilograms * square inches )Taken at the output coordinate system.

Ixx = 0.78 Ixy = 0.00 Ixz = 0.00Iyx = 0.00 Iyy = 22.61 Iyz = 0.00Izx = 0.00 Izy = 0.00 Izz = 23.36

Design B Mass ProperitesMass properties of Modified Lug Wrench Configuration: Default Coordinate system: -- default --

Density = 0.13 kilograms per cubic inch

Mass = 0.41 kilograms

Volume = 3.27 cubic inches

Surface area = 22.75 square inches

Center of mass: ( inches )X = 0.00Y = 0.00Z = 0.97

Principal axes of inertia and principal moments of inertia: ( kilograms * square inches )Taken at the center of mass.

Ix = ( 1.00, 0.00, 0.00) Px = 0.71 Iy = ( 0.00, 0.00, -1.00) Py = 0.72 Iz = ( 0.00, 1.00, 0.00) Pz = 1.40


Moments of inertia: ( kilograms * square inches )Taken at the center of mass and aligned with the output coordinate system.

Lxx = 0.71 Lxy = 0.00 Lxz = 0.00Lyx = 0.00 Lyy = 1.40 Lyz = 0.00Lzx = 0.00 Lzy = 0.00 Lzz = 0.72

Moments of inertia: ( kilograms * square inches )Taken at the output coordinate system.

Ixx = 1.10 Ixy = 0.00 Ixz = 0.00Iyx = 0.00 Iyy = 1.79 Iyz = 0.00Izx = 0.00 Izy = 0.00 Izz = 0.72

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