Proposal to Analyze and Re-Design Wentworth Wobbler Air Engine

Submitted To:

Professor Richard L. Roberts

February 7, 2011

By

Christoper Guliherme

Gregory Leonardi

Stewart Wing

Eric Sullivan

WENTWORTH INSTITUTE OF TECHNOLOGY

Mech 578

guilhermec@wit.edu leonardig@wit.edu wings@wit.edu sullivane3@wit.edu

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Introduction

Wentworth Institute of Technology is moving to keep up with the times, and in doing so is replacing the lathes and milling machines in the manufacturing lab with computer numeric control (CNC) machines. With these new machines, much of the freshmen syllabi will change, especially the creation of an air engine, or wobbler, which was originally done by hand and assembled over a semester. The CNC machines will take a semester long project and complete it in a few weeks, so a new design is necessary for the wobbler. We are proposing to redefine steps taken to complete the wobbler, while tweaking the design to make it more efficient. By working out the kinks or failures of the former design, incoming freshmen will be able to be on the brink of technology and utilize the most efficient manufacturing processes.

Problem Definition

Freshmen enrolled in the Mechanical Engineering Technology at the Wentworth Institute of Technology have the option of taking an introduction to manufacturing processes course in either their first or second semester, at the end of which an engine (also known as a wobbler) fueled off compressed air is assembled. The current curriculum requires that students machine each part pertaining to the assembly through a variety of manufacturing processes, including casting, lathe turning, hand tapping, and press fitting of aluminum pieces. However, beginning next year, the lathes and mills in the manufacturing lab will be obsolete and replaced by machines run by computer numeric control (CNC) codes. This in turn, would hugely affect the process by which the wobbler is built; therefore a new design is necessary. While this design is being created, an opportunity to work out minor kinks to the current engine becomes apparent, such as galling of pieces and gouging of the piston. With the new CNC process an opportunity also arises to eliminate the possibility of human error in the machining of the parts.

Literature Review

The air engine that is to be designed is built around one concept: simplicity. The design, manufacturing, and mechanical workings must all be extremely simple and logical in order to be used as a viable learning tool. The need for minimalism in the design and limit on manufacturing methods is what will pose the most difficulty in the final design.

Most engine designs of the present day are extremely complex and rely on both electronic and mechanical systems to create an extremely efficient energy generation system. As well, most engines are made out of combinations of many different materials which increase cost and often require many different types of manufacturing. The goal of this engine is to be made out of a minimal number of materials and easy to manufacture.

The new engine design will almost completely be based off the original Wentworth Wobbler design. The biggest advantage to this design over other air engines is the simplicity of the cylinder intake and exhaust. The cylinder on most engines is stationary, and through the workings of various valves and gears, intake and exhaust valves into the cylinder are opened and closed during the revolution of the engine. The Wobblers design makes the cylinder a moving part which rocks back and forth to stationary intake and exhaust ports with the revolution of the flywheel. This design characteristic eliminates the

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need for extra moving parts which would complicate both the manufacturing and the mechanical processes.

The Need

With technology on the rise, both within and beyond Wentworth’s campus borders, comes a need to keep up-to-date with the times. Replacing the milling machines and the lathes in the manufacturing laboratory is necessary as they are “yesterday’s trash”. Multiple professors have expressed the need to solve problems in the current design of the wobbler, and with the necessary redesign for CNC machines, comes the ability to work out those problems without much disruption or hassle. An analysis of the current engine design presents the opportunity to implement changes to make it more efficient and long lasting. Furthermore, the design plans for the engine must be easy to read and comprehend, as freshman students with little mechanical experience will be the ones manufacturing the engine. Opportunities to strengthen team-working ability, time management, and the exercise of independence also arise, thus preparing students for real-life career situations.

The Objective

The final design of the Wobbler engine should be an overall more efficient and sound learning tool. The use of CNC machines will help eliminate human error in the manufacturing process and create precise cuts of the engine parts. This, will in turn, create less error in the final assembly of the engine. The power of the engine will also be increased through the new design. Students building the engine will then both record, through testing, and calculate the power output of the engine.

The longevity of the engine will be increased by manufacturing the engine out of harder and more durable materials. One main point of failure in the original Wobbler is the pistons tendency to gall the cylinder since both parts were made of the same soft aluminum. This problem can be fixed by using two different metals that won’t deteriorate quickly. However, the materials used must still be relatively inexpensive and easy to machine.

In order to make keep the Wobbler as a successful learning tool, the design must be easy to understand and to re-create. The desire for simplicity in the design is so the mechanical processes within the engine will be easy to understand. With few moving parts on the engine and clear assembly plans, the engine should reach these goals. This means all freshmen students in the Mechanical Engineering programs at Wentworth should be able to easily create their own air engine. The final Wobbler Engine design will, ideally, be a terrific learning tool for the Wentworth staff to use with students. Students will be able to look at the plans, and within a few classes have all the necessary pieces for their air engine assembly.

The Work Plan

The work plan for this project is straight forward and simple. First the original design of the air engine must be analyzed for any flaws or process improvements. These can include material analysis, component interface issues, simple hardware selection, machining methods, and etc. Once the analysis is complete, methods of improvement and solutions will be discussed and a clear direction will be set in order to move the project along. Models will be edited and CNC code will be written once all problems are solved completely. With the CNC code in hand, some manufacturing can begin. Fixtures will be

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designed and cut along the way to make sure all components are manufactured accurately. Once all fixtures and manufacturing is complete, A prototype can be assembled and tested. The group will analyze the prototype and decided if there is more room for improvement with the design and manufacturing process. The group will make all necessary changes and complete the project after all work is finished.

Task Name Duration StartPre-Proposal 4 days Thu 1/27/11Formal Proposal 4.25 days Wed 2/2/11Model Original Drawings 5 days Tue 2/8/11Modify Models to Fit Our Needs 5 days Tue 2/15/11

Use Excel to Determine the correct sizing for parts 6 days Tue 2/22/11

Create CNC Codes 6 days Tue 2/22/11Create Drawings for New Parts 6 days Tue 2/22/11

Determine Stock Materials Needed 3 days Fri 2/25/11

make fixtures for machining first prototype 3 days Tue 2/22/11

Machine 1 Prototype of Wobbler 6 days Wed 3/2/11

Refine Design to make machining easier 8.5 days Thu 3/10/11

The Qualifications

This project will require knowledge in design, design analysis, CNC programming, manufacturing processes, material science, and electronics. All together the group has experience in all these areas and will be able to accomplish the goals set for this project. Two of the group members have taken a CNC programing class at Wentworth and all have taken a manufacturing processes course at Wentworth. One group member is currently working with a contacted manufacturing company that uses CNC programming and manufacturing process on a daily basis. All members have taken courses in design methods, design analysis, material science, and electronics. With each member bringing something unique to the group this project will be completed in a timely and efficient manner. All members of the group have done projects on their own time that show the dedication to learning outside the classroom. This group is well qualified to complete the given tasks of this project.

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GREGORY LEONARDI13 Summer Street ~ Topsfield, MA 01983gbleonardi@gmail.com ~ 978-766-8179

EDUCATION Wentworth Institute of Technology, Boston, MA Bachelor of Science in Mechanical Engineering Technology

August 2011 exp. GPA 3.22/4.0 Dean’s List Spring 2008, Spring 2009COURSEWORK Strength of Materials Thermodynamics Electricity and

ElectronicsDynamics Mechanical CAD Apps Mechanical Design ICollege Physics II Differential Equations Machine DesignTECHNICAL COMPETENCIESDesign: Hand Sketching, Detail Drawings, Assembly Drawings, Solid ModelingEngineering: Strength Testing, Gauge Reading, Lathe, Milling, Thermocouple, MicrometerSoftware: Microsoft Word, Microsoft Excel, Microsoft PowerPoint, SolidWorks 2008, AutoCAD, Working ModelENGINEERING EXPERIENCEVAV International, Woburn, MA January 2010 – December 2010Spring Intern

Analyzed new Plumbing and HVAC systems to calculate purchasing orders of equipment.

Evaluated existing conditions of HVAC, Plumbing and Fire Protection to create accurate layouts for retrofit designs.

Edited drawing markups to create professional, precise drawings for customers. On site evaluation of customer premise to establish baseline capacity for existing

HVAC and Plumbing system.WORK EXPERIENCE Sandy Point Sailing Association, Beverly, MA June 2004 - August 2009Summer Head Instructor

Supervised and coordinated a staff of six instructors by creating schedules and communicating expectations to ensure a successful program

Communicated with necessary parties including parents, vendors, employees to resolve conflicts

Reviewed and prioritized maintenance schedules and performance of boats to ensure safety on the water as well as longevity of the boats

LEADERSHIP EXPERIENCE Eagle Scout

Coordinated volunteer group at Topsfield Town Library to implement an improved storage system following Sping flooding

Organized patrol of eight scouts and assigned tasks to help built teamwork skills and instill sense of responsibility

Created monthly schedule of events for patrol to work on basic skills and prepare young scouts to become leaders within the troop

ACTIVITIES America Reads

Work with young children on language skills and reading to reinforce fundamentals of English

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Provide positive model for kids to look up to and emphasize the importance of lower and higher level education

INTERESTS Interested in working in green engineering and alternative energy sources such as wind and

solar energy. Also enjoy Sailing, Snowboarding, Hiking, Camping

Christopher Guilherme550 Huntington Avenue

Boston, MA 02115(603) 553-7886

Guilhermec@wit.eduEducation

Wentworth Institute of Technology, Boston, MABachelor of Science Mechanical Engineering Technology

Exp: Aug. 2011GPA: 3.20/4.0

CourseworkMaterial Science Strengths of Materials Machine Design

Statics Mechanical Design II Computer-Aided Manufacturing

Thermodynamics Fluid DynamicsComputer Programming Differential Equations College Physics II

Chemistry Technical Competencies

Software: AutoCAD 2008, Benchmen, SolidWorks 2010, CamWorks 2010, Partmaker, Microsoft Office Suite

Engineering: Mill-turn, Lathe, 4 and 5 axis Milling Machine, Metal Working, Solid Modeling, Basic CNC programmingWork Experience

Seabrook International, Seabrook, NH Jan. 2010 - Present

Manufacturing/Mechanical Co-op Created manufacturing drawings and models to assist the engineering team Compiled process plans and pricing to help the sales team quote future jobs Programmed, setup, and ran mill-turn and 3-5 axis milling equipment

Bioscale, Cambridge, MA May 2009 - Aug. 2009

Mechanical Intern Assembled and maintained detection and automation systems to improve

performance Communicated with 3-6 engineers to complete a large upgrade to the

detection system Compiled purchase orders by speaking with project engineers about what

was neededHome Depot, N. Hampton, NH

May 2008 - Aug. 2008 Lumber Associate

Acted as an integral member of team of 5-6 associates to receive, cut, and stock wood products

Enhanced customer service skills by helping customers find the right supplies

Advised customers on product specifications to insure that the product met their needs

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Eldaar-Craft Design, Hooksett, NH Mar. 2007 - Aug. 2007

Computer Drafter Prepared HVAC and fire protection plans for clients using AutoCAD Generated existing condition plans to aid with the design of new mechanical

systems Gathered information from clients to better my understanding of what was

wanted Project Work

Remote Control Rock Crawler, Derry, NH May 2007 - Aug. 2007

Modified and constructed an electrical powered 1/10th scale vehicle, driven by remote control, to climb over rough and rocky terrain that most remote control vehicles could not travel over. Completed as an independent project

Air Engine, Boston, MA Sep. 2006 - Dec. 2006

Manufactured and assembled an engine that ran on compressed air and was constructed mostly of aluminum parts fabricated with the use of the lathe, milling machine, and aluminum casting process. Completed for Manufacturing Processes I

Leadership Experience Resident Assistant/Senior Resident Assistant Aug. 2007-

Present Coached youth football, youth lacrosse, and youth basketball Aug.

2002- Present

33 High Street (978)758-0506Chelmsford, MA 01824 Sullivane3@wit.eduEDUCATION:

Wentworth Institute of Technology Boston, MABachelor of Science, Mechanical Engineering Technology August 2011GPA: 3.885/4.000 Dean’s list: Fall 2008-Spring 2009

COURSEWORK:Computer Aided Manufacturing Fluid Mechanics Manufacturing Processes IMechanical CAD Applications I Material Science Thermodynamics IStrength of Materials Statics Differential Equations Mechanical Design I Dynamics Electricity and Electronics

TECHNICAL COMPETENCIES:Engineering: Strength Testing, Welding, Casting, MachiningDevices: Lathe, Milling Machine, Drill Press, Proto Trak CNCSoftware: Solidworks, CAMworks, AutoCAD, Autodesk Inventor, Compress, Vantage,

Microsoft (Word, Excel, PowerPoint, Project)ENGINEERING EXPERIENCE:

Artisan Industries Inc. Waltham, MAMechanical Engineering Co-op January 2010-May 2010

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Eric S. Sullivan

Drafting and drawing of components used in Rototherms, Jet Vacuums, and Rotary Valves

Draft and design two shipping frames for a hydraulic unit and a grinder Edit specification sheets to be sent to customers to obtain information about specific jobs Research components to be used in the frames for clearance and ease of use in the field Order parts and supplies from suppliers using Vantage Assist in calculations of some ASME Code parts Participate in discussions concerning the design and use of the hydraulic unit and grinder Redesign drawing templates in Autodesk Inventor to improve readability

OTHER EXPERIENCE:General Woodworking Lowell, MAAssembly Supervisor January 2006 - Present

Organize and maintain the assembly area to ensure materials are available for production Maintain a steady work flow by helping in the assembly process when needed Monitor the inventory in the stock room to ensure that hardware is available Meet scheduled deadlines by closely monitoring the progress of projects Troubleshoot problems that arise in the assembly process Resolve and mediate any conflict within the assembly area Train new employees on company policies and procedures to improve productivity

Great Brook Farm Carlisle, MA Assistant Herdsman May-Aug, 2001-2005

Assisted herdsman in the care of farm and animals and provided care for cranberry bogs Supervised up to six other workers

ACTIVITIES:U.S. Masters Swimming SnowboardingVolunteer at Lowell Catholic Carnival Society of Manufacturing Engineers

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The Budget

One of the goals for this project is to be able to manufacture the wobbler air engine here at Wentworth. It also needs to be as simple as possible so incoming freshmen can spend minimum time building it and more time analyzing. Our budget in turn is very simple and straight forward. Wentworth is providing all necessary equipment and utilities. Also there will not be any outside services because that would add to the cost and complicity of the project. There is money on reserve to cover any unsuspecting costs and money for miscellaneous items.

Operations Cost Percent of TotalPersonnel $0.00 0.00%

Outside Services $0.00 0.00%Utilities $0.00 0.00%

Equipment $0.00 0.00%Materials $450.00 69.23%

Miscellaneous Expenses $100.00 15.38%Reserve $100.00 15.38%

Total $650.00

Project Budget

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The Projects Future

The redesign of the Wobbler Air Engine is the number one priority for Wentworth within this project. However, professors at Wentworth have also expressed a desire to create a dynamometer that will hook up to the engine to measure its power. The dynamometer would be a simple design of just a coil that will light a light bulb when hooked up, and possibly give a digital readout of torque. It will be powered by attaching a belt to the flywheel of the air engine. Although this goal was originally set to be part of the original project, it is more likely that the dynamometer will not be created until a later time.

This project will be used as the basis of the new Mechanical Engineering programs manufacturing course. The engine can be built in a short period time, and then thoroughly analyzed by the students. This is important since the Engineering program is more analytically based, and concentrates less on manufacturing.

Bibliography

The Air Car. 1/28/2011. http://www.theaircar.com/

How Stuff Works. How The Air Car Works. 2/2/2011. http://auto.howstuffworks.com/fuel-efficiency/vehicles/air-car1.htm

Mike Smyth’s Compressed Air Engines. 2/2/2010. http://home.ctlnet.com/~robotguy67/classic_cars/air_engines/V-Twin/air_engines.htm

Wikipedia. http://en.wikipedia.org/wiki/Pneumatic_motor

Appendix

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