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College of Engineering & Science - Louisiana Tech University

Mechanical Engineering

Mechanical Engineering Senior Design Project

Joseph H. Barnwell

Mechanical Engineering Senior Design Contest

May 5, 2007

The 2007 Barnwell Senior Design Contest for Mechanical Engineering students was held in conjunction with the 2007 COES Senior Design Conference. There were sixteen Mechanical Engineering design teams who competed for at total of $1,500 in cash prizes. Here are abstracts of their design presentations.


Quick Connect 4

Team Members: Errin Combest, Megan Dagate, Stephen Feazell, and Matt Jones
Project Sponsor: Aeropres Corporation

Aeropres Corporation is located in Sibley, Louisiana and run by Mr. James McKeever, a Tech graduate. Aeropres is the largest distributor of ecologically safe propellants. Aeropress responsibilities include sandblasting cylinders, vacuuming and filling the cylinders, and shipping these cylinders to customers. The current process for connecting the vacuum and fill lines at the Aeropres facility involves threaded connections, which are tedious and time-consuming for the operator. The purpose of our project is to design a quick connection for use with the vacuum system. The fitting should be one piece and incorporate a valve that prevents flow when a cylinder is not connected. The fitting should have a minimum working pressure of 350 psig and be compatible with dimethyl ether (DME), a propellant distributed by Aeropres. After completing the conceptual design phase, further research revealed a product patented and manufactured by WEH of Germany and distributed by FasTest, Inc. of USA that was adaptable for the desired service. After selecting this design, Quick Connect 4 and FasTest, Inc. worked very closely in selecting appropriate materials for the quick connect. After closely reviewing the quote and operations manual from FasTest, Quick Connect 4 ordered the connection. During the following weeks, Quick Connect 4 performed a time motion study at Aeropres to optimize the current vacuum and filling processes, and the team carefully developed a testing procedure in anticipation of the quick connects arrival . At the senior design conference, Quick Connect 4 will discuss the design process and present the testing results.


SAE Mini Baja: Hydraulic Drive System

Team Members: Charles Colvin, Obinna Ugwuegbu, Reginald Draper, Jeremy Gourdon

The miniature baja vehicle that we are producing within the Society of Automotive Engineers at Louisiana Tech University must be able to propel itself in some manner by a 10 horsepower Briggs and Stratton internal combustion engine. In the past the drive system has been designed as a mechanical linkage; this year the Society of Automotive Engineers at Louisiana Tech University has mandated that the internal combustion engine must be located in the front of the vehicle and a hydraulic drive system must be used to power the vehicle. The hydraulic design system is intended for propulsion of the mini baja vehicle and also as a learning experience for engineers at LaTech.

The closed loop hydraulic drive system has been designed to produce a vehicle that will travel at 30 mph on land and be maneuverable in water. The drive system will use actuators such as: a tri-hull design with a center, in-board propeller driven with a 750 rpm Eaton J-2 motor and a wheel motor driving the back wheels that outputs 3250 inch-lbs of torque. The hydraulic system is controlled by a control valve operated with a throttle pedal. A selector valve is located under the steering wheel so the driver may select land or water propulsion. The hydraulic system is designed for 16 GPM at 3000 psi operating flow and pressure respectively utilizing a 2-Stage Haldex pump.

The drive system will be tested on April 12-15 2007, at Ocala, Florida at the SAE competition. The tests include an incline test, speed test, water maneuverability test, technical safety inspection test, and an endurance test.

Nomis Trigger-Lock Mechanism

Team Members: Nick McGrew, Jeff Jordan, Chris Williamson, and Roman Fields
Project Sponsor: NOMIS, Inc.

The goal of this senior design project was to develop a trigger-lock mechanism to be used in conjunction with a previous senior design team's optical sighting system. Basically, last year's design team determined that a user could ‘mark' a target with their laser optical system. This system would recognize when the laser-equipped rifle was on or off the selected target. This year's design team's goal was to modify the firing actuation of the rifle mechanically so that it would require a signal from the sighting device to initiate the firing sequence. A trigger block was designed that, even after the trigger was pulled, would actually wait until the rifle was on target before firing. This design would effectively reduce missed targets due to rifle movement and other such variables. The overall design specification required that the firearm would operate normally when the system was off. The manufacturer's safety remained unchanged and was still fully operational. Both of these systems would be mounted onto a Remington 700 bolt-action rifle. The project sponsor wanted the Remington rifle to be used because of its availability and popularity. The sponsor also wanted the design to be easy to manufacture with little or no specialized parts. This meant that off-the-shelf components were to be used wherever possible. This design requirement would also help to keep manufacturing costs down. The NOMIS trigger-lock mechanism designed by Team Surefire fulfills all of these performance requirements.


Golf Cart Weed Eater

Team Members: Daren Yeowell, Wesley Gray, Brynan Arnold, and David Burleigh
Sponsored by: Fairway Carts

The idea of the golf cart weed eater was conceived by Mr. Larry Tims of Fairway Carts in Minden, Louisiana. While discussing course maintenance with a golf course owner, the benefits of having a vehicle mounted weed eater were pointed out. Mr. Tims later built a rough working prototype of the system with little or no engineering analysis used in the design of the system. The original model was belt driven by a 2.3 horsepower motor, it contained two pulleys and used a rigidly attached skid, and the whole system was permanently mounted on the rear of the cart. With the success of the original prototype, Mr. Tims recognized the potential of his idea. Consequently, he approached Louisiana Tech University for assistance in the development of a fully engineered golf cart weed eater.

To reach a justified final design, the project went through the following phases: Engineering Design Specification, Conceptual Design, Parametric Design, Preliminary Design, and Final Design. The engineering design specification phase was used to serve as a guide throughout the project on factors such as safety, portability, and performance. After the completion of the previously mentioned phases, a final design was decided upon which includes the following features: 2.3 hp electric motor, adjustable skid, safety cut off switch, break away boom, four string cutter head, front mounting, and the ability to be used on multiple carts.

Quick Connect Fill Valve for Aeropres Corporation

Team Members: Matt Ferrel, Patrick Mears, Ian Haneline, Jeff Davis

This industrially sponsored project goal was to design a quick connect type fitting for use with the Aeropres vacuum system. The quick connect must connect to the Neriki Gas Valve which is the valve Aeropres uses to fill their smaller tanks.

The quick connect should take no longer then five seconds to attach and must not damage the threads or gas valve during operation. The device needs to incorporate a shut-off valve that prevents flow when the device is not connected to a cylinder and must not hinder operation of the knobs on the Neriki Gas Valve.

Aeropres intends to use the device to fill tanks with aerosol propellants. The propellants are made from propane, butanes, dimethyl ether (DME), difluroethane (R 152a), or combinations thereof. Due to the nature of the gases, the device must be non-sparking.

The fitting should have a minimum working pressure of 450 psig and compatible with the previously listed materials.

The A-Team's design utilized the back side of the valve to provide support for a device that would clamp the POL connector into the Neriki Gas Valve. The prototype is called the Mercy Connect and is a completely original design. The A-Team manufactured nearly every part on the device from raw materials. The prototype exceeds all expectations listed by Aeropres in testing and suits the needs of the company.

Ashrae Design Team

Team Members: Michael Hochstetler, Ryan Peters, Phillip Magill

The purpose of the ASHRAE Design Competition was to design and select a heating, ventilation, and air conditioning (HVAC) system for a selected building. The project selected for this year was a four story building in Lower Manhattan that was renovated for the use of a research company called ImClone. The warehouse space that was once used by the United Parcel Service was converted into office space and laboratory facilities used for cancer research.
ASHRAE will be evaluating the projects on initial costs, operating costs, reliability, flexibility, maintainability, and sustainability with emphasis on a green design. With these criteria in mind, we selected a system that will include a water chilled cooler and variable air volume (VAV) air handling systems. The water chilled cooler and VAV system is slightly more expensive initially, but is more reliable and energy efficient, which helps the environment and lowers the monthly costs.

With the help of Purtle and Associates, and mechanical engineering consultant firm in Shreveport, we were able to gain access to load calculation software that is currently in use in the HVAC industry. The results of this software indicated a total load of 345 tons, which we divided into seven air-handling units. We were also able to select a chiller and water tower to accommodate the 345-ton total load.

ASME Human-Powered Potable Water Still

Team Members: Brandon Mik, Daniel Ray, Jonathan Friedmann, Paul O'Meallie

ASME required that a device be built that would distill water over the course of an hour using only human input as a form of power. The purpose of this project is in response to the 3rd world countries that are lacking clean water, as well as Katrina victims who were surrounded by water but could drink none of it. To accomplish this task, our team has built a device that uses an exercise bike to utilize human mechanical input to turn an alternator that generates electricity. This electricity is then run through a heating element to generate thermal energy to boil the water. The vapor will run through a condenser to be returned to liquid water. After the water has exited the condenser, it will be cooled to approximately room temperature and will be clean and ready to drink.

Team TLA: Human-Powered Water Still

Team Members: Joe Fortenberry, Matt Drake, Will Smith, Patrick Doiron

"Water, water everywhere and not a drop to drink."
Coleridge, "The Ryme of the Ancient Mariner"

In certain disasters, people are left without a source of clean drinkable water, much akin to the situation of the ancient mariner. In such cases there is typically plenty of water around, but is somehow undrinkable due to pollutants, or even the presence of salt. In these circumstances, there is generally no electricity available to boil water in order to remove the pollutants. As a result, the American Society of Mechanical Engineers (ASME) has formulated a design competition to develop a potable water still that utilizes only human power.

To meet the requirements set forth by ASME, team TLA has designed a still that converts mechanical human power directly to heat through friction. The project utilizes friction between a steel and copper plate with a normal force between the plates of approximately 100lbs provided by four compression springs. This boiling assembly rests on a bicycle frame, on which the back wheel is replaced with custom machined shafts to transfer the mechanical energy from the pedals to the rotating plates.

Team Waterboy: Human-Powered Water Still

Team Members: Ross Chauvin, Ryan Daigle, Jesse Herrera, Matthew McCoy

Due to recent events, it has been shown that victims of disasters who are faced with no electricity and no safe drinking water have no method of converting polluted water into potable water. A project is needed to design, prototype, and test a human powered water still that is both safe and easy to use, as well as being cost effective.

The project team will design, build, prototype, and test a human powered water still for use in emergency situations. The team will evaluate customer and company requirements, develop alternative still concepts, configure a still alternative, establish feasible design variable values, prototype configurations, and test the final configuration.

"Build a device which will heat water to reach boiling temperatures, and then condense the steam generated to get potable water." This is the basis of our design project as set forth by the ASME guidelines. The goal is to prove whether or not it is feasible to produce potable water from a human powered water still. In recent times of disaster such as hurricane Katrina a device such as this was needed more than ever when victims were stranded on rooftops surrounded by flooded polluted waters and not a drop of drinking water available. Going beyond times of disaster, this device would prove beneficial to third world countries which do not have running drinking water along with no electricity.

The initial criteria set forth by ASME are listed as such:

Team DVII: American Society of Mechanical Engineers (ASME)

Team Members: Chris O'Rear, Michael McDaniel, Rocky Portillo, Jane Petrus

The challenge is to design a potable water still that has the capabilities to purify water using only human power. The competition allots one hour for the team to distill 200mL. The method chosen by Team DVII includes using the rear tire of a bicycle to spin an automotive generator. The generator will create electrical energy, which will supply voltage to a heating element made of nichrome wire. The nichrome wire will be placed inside the boiling chamber, where the water will be boiled. After boiling, the condensation will collect in the cooling coil and fall into the collection chamber.

Team members plan on competing in the Student Professional Development Conference on April 13-14, 2007 in Tulsa, Oklahoma. We would also like to express gratitude to our sponsors for their financial support: Intralox, L.L.C., Petrus Feed and Seed, and the Louisiana Tech Student Government Association. We also appreciate all the professors at Tech who have given us advice and assistance throughout our project.

SAE Mini Baja: Frame and Buoyancy

Team Members: Chris Corkern, Cory Sipes, Rocky Guirlando, Evan Marshall

The purpose of the mini Baja project was to design and fabricate a frame and buoyancy system that utilizes real world engineering skills. The specifications for the mini Baja were given by the Louisiana Tech University chapter of the Society of Automotive Engineers and the University of Central Florida competition rules. The frame was constructed of 4130 alloy steel and designed to take up minimal three dimensional space surrounding the biggest driver. The frame was generated by the 3D modeling program NX-4. Finite element analysis was conducted on the frame by using the program ANSYS. The buoyancy system was constructed with two goals in mind: the ability to withstand off-road travel conditions and the ability to keep the vehicle afloat with stability in two directions (pitch and roll). The buoyancy system was generated in the 3D program Solid Edge and inserted into NX-4 to complete the modeling setup. The floatation device consists of polyethylene foam wrapped in fibreglass with a vinyl polymer coating applied on the surface. With the frame and buoyancy system built to our desired specifications, the mini Baja should be able to withstand any off-road conditions.

SAE Mini Baja: Suspension

Team Members: Jory Coon, Kevin Booth, David Smith

Design Problem: Our Group was chosen to design a front and rear suspension system for the Mini Baja car Design Competition. This Mini Baja car will endure many different obstacles and will be entered in many different events that will test its suspension as well as other things to the limits. The suspension must be very versatile, in that the car will weigh approximately 500 lbs and it must be able to accommodate drivers from 120 lbs up to 280 lbs.
Intended purpose or use: The purpose of the suspension on this Baja car is to not only allow it to stick to the contours of any obstacle it may encounter, but also to plush the ride of the driver and soften the impact of anything the car may encounter. The track the Baja car will be competing on will have jumps, holes, turns, and any other thing that could be thrown at a car to test it to the limits.

Unintended purpose: Ability to have the shock mount positions changed allowing extreme ground clearance for a possible mud bog competition.

Special features: Should be plush enough to allow a soft ride for the driver as well as allow for the handling characteristics described above.

SAE Mini Baja: Brake Team

Team Members: Jonathan Fasullo, Donal Johnson, Heather Bradley, Gene Bentley

The braking system is an essential part of every vehicle and is needed for the safety of every driver. Design details of the hydraulic braking system for the 2007 Mini Baja vehicle are revealed within this report. The design of the system was originally for a 780 pound vehicle that operates on both land and water. Discussed in the first section of the report are the feasible conceptual designs based on the SAE regulations and driver safety considerations made by the design team. These concepts were then weighted to see which design would meet the engineering design specification. When considering the braking system configuration, six components were analyzed: brake pedal mount, rotor selection, master cylinder configuration, brake line type, final braking device (i.e. drum or disc brake), and brake light setup. In each category the cost, efficiency, effectiveness, performance, and availability were considered and weighed. In the final section of the report, the testing methods used to determine the efficiency of the designed brakes are discussed. In each test, stopping distance and time were monitored. These sections of the report combine to complete the entire design process of the 2007 Mini Baja braking system.

Mars Rover Thermal System Trade Study and Alpha Prototype

Team Members: Amy Cain, Joseph McMahan, Bryan Powell, Heath Myatt

This senior design project consists of two projects. The first part of the senior design project is to conduct a trade study on an appropriate Mars rover thermal system. The second part of the trade study consists of the design and construction of an alpha prototype. The Martian surface reaches temperatures from a high of 0°C during the daytime to a low of -90°C at night. A diverse collection of existing thermal systems are considered and compared for their ability to control the rover internal temperature in the Mars environment. The systems considered are the Swales Cryogenic capillary pumped loop, a regulated insulation system, Hewlett Packard's Compact Thermosyphon, and the miniature loop heat pipe currently used by NASA. A comparison reveals the potential for a well designed miniature loop heat pipe to be used on future Mars rovers. The second part of this senior design project involves designing and building an alpha prototype of the miniature loop heat pipe. A miniature loop heat pipe is designed for the Martian environment. A second miniature loop heat pipe is designed for an earth environment and is testing purposes. Tests are performed on the alpha prototype in order to qualify the concepts behind the design.

CNC Milling Machine

Team Members: Michael Wissing, Justin Keen, Thomas Doiron, Chad Murphy

The purpose of the CNC project is to develop and engineer a portable CNC milling machine. The machine requirements are to have a portable machine that could be easily transported and fully operate at any given time. The final design of the CNC machine consists of converting a typical mini-drill press into a CNC machine. The machine will have 3-axes travel allowance with the help of an attached 2-axes milling table. Three 200oz-in stepper motors will be used to operate the 3-axes movement. Two stepper motors will be attached to the lead screws of the milling table and the other stepper motor will be attached directly to the drill press on the vertical lead screw. The stepper motors will be controlled directly by a computer that is constructed by our design group. The main operating program for the CNC computer is TurboCNC. A laptop will be connected to the CNC computer to run TurboCNC. The coding used to run TurboCNC will come from NX 4.0(licensed by Louisiana Tech University) as a form of G-code. The G-code is a coded breakdown of the milling operations for a 3-D object designed in NX 4.0. With the correct G-code an exact replica of an object designed in NX 4.0 will be built on our CNC milling machine. Our machine is designed to handle a part size 4 to 5 in3, but will be able to produce larger objects if needed. Overall, the design project is intended to create a milling machine that will be given back to Louisiana Tech University. The CNC machine will be capable to operate in any classroom environment and/or as a student recruitment tool for Louisiana Tech University.

Hydro-Formed Seal for a Service Lateral

Team Members: Chad Blanchard, Sabir Hussain, Allen Minner, Zamir Hussain

Residential and commercial water mains distribute potable water to end users through service laterals that connect the users plumbing system to the water main. During their service life, the main pipes are subject to physical damage and chemical deterioration. In many cases, the integrity of the pipe has been compromised to the point that functionality must be restored by lining the pipe with a high-density polyethylene (HDPE) pipe of a smaller diameter. In industry, "rehabilitation" is the term used when referring to this restoration process.

Rehabilitated water mains require a cost effective method for reestablishing leak-free service lateral connections. Desirable methods would not include digging due to the time consumption and huge expenses involved. Using a robot, an inexpensive method for precisely cutting a hole through the HDPE liner at the location of the service lateral has been produced. This method is conducted from within the HDPE pipe, eliminating the method of digging. Once the hole is drilled by the robot, a gap between the liner pipe and preexisting pipe exist, increasing the risk of contamination of the water supply. The team has been commissioned to design a means of sealing this gap, preventing water leakage between the liner pipe and preexisting pipe. The process is to be carried out by a pipe robot from inside the HDPE liner and the seal must be formed by a hydro-forming process.