Group 29 - Homelite Line Trimmer
Addressed herein is the reverse engineering of the UT 15151 Homelite® VersaTool™ line trimmer undertaken by group 29 of MAE 277, SUNY-Buffalo, for the Fall 2009 semester. Documentation of the development of the semester-long project entails a record of an evolving engineering process distilled into five discrete, successive "gates", designated as the following:
- Gate I: Request for Proposal, which contains details germane to the Work Proposal, Project Management and the Initial Product Assessment;
- Gate II: Preliminary Project Review, which consists of Causes for Corrective Action and the Product Dissection Plan;
- Gate III: Coordination Review, which includes a Component Summary, Design Revisions, a Solid Modeled Assembly, and an Engineering Analysis apposite to the vital mechanics of the product;
- Gate IV: Critical Project Review, which provides a step-by-step account of the product's reassembly, articulated in Product Reassembly Plan;
- Gate V: Delivery, which marks submission of the final edition of the technical report in its entirety.
Motivation for this maiden enterprise evoking application of fundamental engineering principles to technical communication, analysis and design arose from the stimulus of MAE 277 coursework, as alluded to earlier, with the Reverse Engineering Team Project amounting to a substantial percentage of the course material and overall grade. Apart from this, genuine and sustained enthusiasm about reverse engineering physical machinery, together with sound responsibility in attending to delegated work, thereby enabling submittal of deliverables per deadline, proved to be the lone additional catalyst necessary for constructive progress during the course of the project.
What follows is the summation of a collective effort at reverse engineering the UT 15151 Homelite® VersaTool™ line trimmer within a period of approximately four months.
For the duration of the Fall 2009 semester at SUNY-Buffalo, group 29 of MAE 277 immersed itself in a Reverse Engineering Team Project centered on the UT 15151 Homelite® VersaTool™ line trimmer. Throughout the project’s development, the group’s collective toil adhered to a structured agenda as set forth by the presiding instructor of the course. As such, the body of components constituting the project, and the group’s management of the tasks involved therein, lends itself to the following overview.
In keeping with the coordination of labor as facilitated by the group’s Gantt chart, product dissection was anticipated to last ten days, mainly owing to conflicting personal schedules among members. This inconvenience and difficulty in securing mass group work, however, amounted to a rather serendipitous boon; that is, were all members to convene at an arranged time at the product dissection lab furnished by the School of Engineering and Applied Sciences, confusion and congestion of workflow would have proved inevitable. In a word, having the five members of the group simultaneously laboring on either the disassembly or the reassembly, or perhaps both, would have spelled mere detriment to the work on the product, in light of the of spatially restrictive environment of the facility wherein labwork was conducted.
Much to the benefit of the group in terms of time management, physical disassembly of the product was completed in two intervals over the course of two consecutive days (i.e., three hours on the first day, and one hour on the following day). This allowed for acceleration of the work schedule and earlier "start dates" on tasks of respective gates than had been projected in the Gantt chart.
Multiple layers of the reverse engineering project gained form and order posterior to completion of the product's disassembly. Namely, in an effort to devise a methodical approach to analyzing the product with respect to expressly defined criteria, including from a standpoint that assessed design involving functional, marketable, manufacturing, and economic variables, the group channeled the enterprise into sub-sections of each gate. More precisely, to guide and ensure sustained concentration and preserve a positive morale and work ethic within the group, the group generated a Causes for Corrective Action as the need arose, particularly following the Request for Proposal (i.e., Gate I) and the unexpectedly expeditious disassembly during the Preliminary Project Review (i.e., Gate II). In addition to this managerial component, the group detailed its disassembly using such organizational media as charts, annotated with relevant text and corresponding visuals, enabled by the services provided gratis by the Wiki Media platform.
Advancing beyond the illustrated and descriptive exposition supplied in the Preliminary Project Review, the group's technicians, both the mechanically knowledgeable and those well versed in modern software-based applications designed for computer-aided drafting and solid modeling purposes, tackled the product documentation and analysis of the Coordination Review (i.e., Gate III). Delegated among members so as to ensure concurrent development of the sub-sections, various responsibilities involved (i) compiling a charted list (located in the Component Summary) of the components identified during the disassembly; (ii) conception of three design revisions to the product (found in the eponymous sub-section, Design Revisions); (iii) three-dimensional rendering of the component assembly (located in the Solid Modeled Assembly sub-section) judged indispensable to the product's means of operation; and an Engineering Analysis for which the group availed itself of the solid geometry and component assembly visualized in the Solid Modeled Assembly sub-section.
Design revisions, further expanded in their respective subsection, were arrived at and realized by imposing such outweighing factors that underscored economy of weight, curtailment of costs to both the manufacturer and ultimately the consumer, and a manufacturing-oriented pragmatism to ensure the recommendations proved technically feasible while not comprising the former two criteria. Together with the Engineering Analysis, the outcome of which substantiated the conjectured location of potential product failure, the suggested design revisions are anchored to the central concern of ameliorating the exterior of the product; this concern remains warranted and tenable, however, only as long as the group avoids undue adjustment to the internal mechanics, mechanisms, and components that may unfavorably affect the competitive retail and market value of the product.
As coda to the preamble of the technical report addressing the reverse engineering of the UT 15151 Homelite® VersaTool™ line trimmer, product reassembly (which constitutes the Critical Project Review, or Gate IV) received a day's-worth of manual labor, again defying expectations projected in the Gantt chart, which was originally conceived at the incipient planning stage of the enterprise that serves as the subject matter of this report.
In the following content, the project's development and results thereof are presented in the logical sequence and coherent manner as expressed in the preceding lines of the Introduction.
Gate I: Request for Proposal
Below are arranged, in sequence, links to the subsections constituting the Request for Proposal.
Date Submitted: October 10, 2009
Gate II: Preliminary Project Review
The following links entail the Causes for Corrective Action and the Product Dissection Plan of the Preliminary Project Review.
Date Submitted: October 30, 2009
Gate III: Coordination Review
The links below lead to the subsections (Component Summary, Design Revisions, Solid Modeled Assembly, and Engineering Analysis, respectively) comprising the Coordination Review. Access to the subsection References to Supplementary Material is provided in the Engineering Analysis, the content of which corresponds with the noted references to outside literature and kindred online sources of the former.
Date Submitted: November 30, 2009
Gate IV: Critical Project Review
The following links to the Product Reassembly Plan constituting the Critical Project Review.
Date Submitted: December 7, 2009
Gate V: Delivery
This signals the completion of the Reverse Engineering Team Project on the UT 15151 Homelite® VersaTool™ line trimmer. All content represented herein constitutes the technical report of group 29 as was formally concluded and submitted on the final delivery date.
Date Submitted: December 14, 2009
List of Tables and Figures