Engineering Commons^™

Maitreya Desalination, Riley Taft, Hudson Kispert, Brendan Dizon

Mechanical Engineering

This document relays the design and manufacture of a dual power input Reverse Osmosis desalination unit. It's power sources are electric drive and human power via recumbent seated cycling. Fresh water outputs range from 4 - 7 GPH for human power inputs of 150 - 280 Watts depending on the selected gearing ratio from the derailleur.

Parametric Bicycle Yoke, Colin Reay, Walter Minehart, Robby Harrigan, Jordan Olson

Mechanical Engineering

This report outlines the entire design, fabrication, and validation process of a parametric yoke design that addresses the packaging problem of the bottom-bracket chainstay junction in modern bicycle frames. The goal was to create an elegant, space-efficient solution that is accessible to the Cal Poly Bike Builders Club. The report includes documentation of the three-part fixture system, manufacturing process, and testing results for the yoke.

Our yoke design outperforms traditional round-tube weldments in torsional and vertical stiffness. Additionally, all manufacturing fixtures and machining operations function as intended, resulting in a finished yoke that meets all required tolerances in under an …

Bespoke Bicycle Enclosure, Thomas Link, Kyle Mcafee, Marc Monier, Hunter Walden

Mechanical Engineering

Brian Higgins is an American veteran with retinitis pigmentosa who relies on cycling for transportation. The motivation for this project is to design and manufacture a refined prototype bicycle attachment to support him while biking in the rain and cold. The attachment will serve to enclose him for optimal protection from inclement weather, while maintaining sufficient mobility for daily cycling. Mr. Higgins’ bicycle is equipped with an attached sensor system which assists his visual impairment by using an ultrasonic sensor. Therefore, the attachment cannot adversely affect the function of the sensor system. The project timeline is set at approximately 7 …

Adjustable Head Tube Angle Headset, Glenn Petersen, Ben Harper, Josh Martin, Dylan Prins

Mechanical Engineering

This final design review report describes the design, manufacture, and test process of a bicycle headset capable of quickly and easily adjusting the effective head tube angle. The evolution of mountain bike geometry has forced bike designers to compromise between climbing and descending performance when choosing a head tube angle. A headset capable of quickly adjusting the effective head tube angle would allow riders to optimize their bike’s geometry for different stages of riding. This report details the research, idea generation, concept development and selection, design, manufacturing, and testing of our adjustable head tube angle headset.

Bicycle Headset With Adjustable Spring Rate, Andrew W. Drees, Jonah Masumoto, Camden R.S. Boshart, Matthew B. Mounteer

Mechanical Engineering

Fork flop can play an important role in the performance of a mountain bike. This phenomenon of fork flop is known as the tendency that the front wheel of a bike wants to flop over to one side when moving slowly. The fork flop experienced on a bicycle changes with the geometry of the bike, but our team sought to change the fork flop experienced through an adjustable internal spring design that attaches to the bicycle instead. From our research, we decided to utilize torsion springs as the method for mitigating fork flop. We also decided to use load cells …

Bicycle Wheel Aerodynamics Predictions Using Cfd: Efficiency Using Blade Element Method, Drew Vigne

Honors Undergraduate Theses

The cycling industry has long relied on expensive wind tunnel testing when designing aerodynamic products, particularly in the context of wheels which account for 10 to 15 percent of a cyclist's total aerodynamic drag. With the recent advent of Computational Fluid Dynamics (CFD), the industry now has an economical tool to supplement the wheel design process; however, the complex nature of rotating spoked wheels requires high resolution meshes to model at acceptable fidelity. This research investigates an alternative CFD method that lowers the computational cost of modeling aerodynamic bicycle wheels by modeling spokes using Blade Element Method (BEM). Two CFD …

Efficiency Analysis Of Harvesting Solar Energy To Perform Mechanical Work, Haden S. Bragg

Undergraduate Theses and Capstone Projects

The majority of the world’s electricity is generated using fossil fuels; in fact, the United States Energy Information Administration (EIA) states that the U.S. used fossil fuels to generate 62.7 % of its electricity in 2019 [1]. The goal of this research was to create a system that could perform mechanical work using only renewable resources. We built a solar charging station that uses two solar panels to generate electricity and an electric bicycle whose battery can be charged using the charging station. The efficiency for the type of solar cell used in this project is well established. Therefore, in …

Human Powered Vehicle Trainer, Nicholas Hung Nguyen, Gregory Reece Bridges, Jacinta Garcia, Mitchell Sidney Smith

Mechanical Engineering

This Final Design Review (FDR) document describes the final design and completed prototype of a Mechanical Engineering senior project team at California Polytechnic State University, San Luis Obispo. The project goal is to create an adjustable human powered vehicle training bike for George Leone that allows a rider to gain confidence with the unique reclined bike geometry ahead of the World Human Powered Speed Challenge at Battle Mountain, Nevada. This document outlines the customer’s needs and technical research performed which together determine the project’s scope and engineering specifications. Next, we present the initial idea generation process and its results, along …

Fluid Power Vehicle Challenge - The Incompressibles - Final Design Report, Nicholas Gholdoian, Russell Posin, David Vitt, Alex Knickerbocker, Kyle Franck, Julian Rodkiewicz

Mechanical Engineering

This report provides a comprehensive description of the research, analysis and design work that The Incompressibles have completed thus far in the senior project process. This document includes all the work that The Incompressibles have completed for the team’s Preliminary Design Review (PDR), Critical Design Review (CDR), the work leading up to the 2019 FPVC competiton and the competition results. This report includes the initial research that the team completed for the fluid power competition, first iterations of designs, final iterations of designs, manufacturing results and processes, and finally testing and results from competition. With a new design for the …

Recumbent Bicycle Balancing Aid, James Hager

Williams Honors College, Honors Research Projects

For our senior design project, our team will be consulting to create a balancing aid system intended for the recumbent bicycle shown below in Figure 1. The owner of the bicycle is Robert Henderson, a former United States Navy sailor from Northeast Ohio who picked up biking and skiing while he was stationed in Maine in the late 80’s. While there, he took to the mountains on the rugged terrain and brought this passion of biking back home to share with his wife, Johanna once he completed his service to his country. Biking became an integral part of the …

Single Arm Recumbent Bicycle, Alexander Borsotti, Ryan Westermann, Sean Liston

Mechanical Engineering

The goal of this report is to outline and cover the scope of work for the Single Arm Recumbent Bicycle Senior Project. The report will give an introduction of the problem, a background of the existing research or products relating to our project, the objectives of our project, our project management plan, our final design, manufacturing, testing, our project management, and final recommendations for improving the final design. The team is being supported by the Quality of Life Program, a non-profit organization that works to improve the lives of those injured in duty while serving our nation.

Up until now, …

Bicycle Power Meter, Andrew Mcguan

Computer Engineering

A power meter is a cycling training tool used to record the power a rider is outputting. This is very useful to athletes who regularly do bike workouts, because the power output is a consistent measure of the rider’s effort level, and is not affected by outside factors such as wind or road gradient. If a cyclist does a workout with the intent to carry a certain speed for a certain amount of time, a strong headwind will slow them down and make them work harder to maintain the same speed, defeating the goal of the workout. When a power …

Team Joseph's Bike Trailer, Keely Thompson, Curtis Wathne, Ryan Meinhardt

Mechanical Engineering

This final design report shows the results of this senior project’s design process of creating a custom bike trailer for Team Joseph. As done in the Scope of Work, Preliminary Design report, and Critical Design report, current products, relevant technologies, and American Society for Testing and Materials (ASTM) standards are fully researched and benchmarked to aid in the design selection process. Customer requirements are looked at and developed into engineering specifications. A detailed design was created for CDR to show to Team Joseph, and manufacturing and testing plans were laid out. This final design report adds the final design revisions …

Development Of Empirical And Virtual Tools For The Study Of Bicycle Safety, Brent Kostich

Masters Theses

Bicycles have been used as a form of non-motorized transportation for several hundred years. Recently, their use in the transportation realm has been reinvigorated because of growing population densities and efforts to improve environmental sustainability. However, a large deterrent for public use of the bicycle is concern over its level of safety in the transportation environment. The goal of this thesis is to develop two complementary research tools that advance the study of bicycle safety factors.

First, an instrumented probe bicycle (IPB) is constructed from the ground up. The bicycle is outfitted with an array of sensors that are integrated …

Cal Poly Compost Chomper, David Anthony Jungquist, Cory James Parmenter, Joseph Mark Mcgill

Mechanical Engineering

The purpose of this final design report is to detail the design, manufacturing, and testing of a bicycle powered compost cutter for use by the Captain Raymond Collin’s Elementary school. Students in the garden program are tired of manually chopping up garden waste into small enough pieces to be composted effectively. Project Sponsor and Master Gardener, Susan Deogracias had the idea to create a pedal powered compost cutter which would save time and improve moral for the aspiring gardeners.

This report details the ideation process the team went through in defining the compost cutting system. Engineering methods are documented for …

Wheelieking Trainer Project Report, Harold Hall Iii, Nathaniel Fox, Thomas Niemisto

Biomedical Engineering

In this report we will detail the design and implementation process of the WheelieKing Trainer project, a device that helps people learn how to do wheelies on a bicycle by preventing backward falls. Formal project requirements are specified, followed by the ideation and iteration process to meet those requirements. The components and methods used to create the device are described in detail. The results of the development process and usage test results of the device are included. Appendices at the end of this report include references, supporting analyses, and project management and timeline details.

Pedal-Powered Drivetrain System, Geremy J. Patterson, Callaghan Fenerty, Bradley Welch

Mechanical Engineering

No abstract provided.

Bike Lock Combining Strength And Flexibility, Zachary Uhrich

All Undergraduate Projects

What can be done when someone is riding a bicycle in a large metropolitan area, and when they reach their destination they find that there either is no bike rack, or the rack is already full. For bikers who prefer the security of a standard U-lock, this means having to leave to find another rack elsewhere or leave your bike unlocked. This situation is the why there is a need for a bike lock which can combine the security of a U-lock, with the flexibility and size of a chain. This project solves the problem by using a hardened steel …

Mechanical Testing Of Fused Filament 3-D Printed Components For Distributed Manufacturing, Nagendra Gautam Tanikella

Dissertations, Master's Theses and Master's Reports

Fused filament fabrication (FFF)-based open-source 3-D printers offer the potential of decentralized manufacturing both in developing and developed countries. Unfortunately, a severe lack of data and standards relating to material properties and printed components limit this potential. This thesis first investigates the mechanical properties of a wide-range of FFF materials and provides a database of mechanical strength of the materials tested. The results demonstrate that the tensile strength of a 3-D printed specimen depends largely on the mass of the specimen, which provides a means to estimate the strength of 3-D printed components. Then this information is used to evaluate …

Design Of An Automated Vehicle Detection System For Bicycles: Fireworks Cycling Sensor, Jason Cheng, Peter Kim, Tory Morgan, Clayton Young

Industrial and Manufacturing Engineering

Abstract

This report explores the necessity for increased cyclist safety in urban settings, leading to the birth of a product which aims to drastically reduce the risk of accidents while heightening the sense of safety overall. The project outlines and details the product development process of a consumer-friendly vehicle detection system, with a holistic scope which includes technical rapid prototyping and coding, team dynamics, decision making process, and change management. Two formal prototypes were developed before a functional final product was identified and constructed, each iteration drastically improving practicality and efficiency of detection. The final product underwent extensive testing in …

Cable Drag Test, Alex Powers, Brandon Sadiarin, George Rodriguez Iv, Torey Kruisheer

Mechanical Engineering

The Smooth Shifters is a team composed of Alex Powers, Brandon Roy Sadiarin, George Rodriguez, and Torey Kruisheer. We are four senior mechanical engineering students at California Polytechnic State University (Cal Poly) in San Luis Obispo, California that are working on a senior design project for Specialized Bicycle Components, Inc. located in Morgan Hill, California. We will be under the advisement of Professor Sarah T. Harding of the mechanical engineering department at Cal Poly.

Specialized, one of today’s leading bicycle companies, is in need of a test setup that measures brake and shifter cable drag. High performance cyclists using time …

Veloelectric: Creating A Device That Harvests Energy From Bicycles, Austin Hall, Daniel Stohr, Tj Fox

Mechanical Engineering

Long distance mountain bikers, bike-packers, and many bikers in developing countries rely on electrical devices for safety and communication. These specific groups of people operate in areas with little to no electricity, and often times have no power to sustain their devices. The purpose of this Cal Poly senior project, VeloElectric, was to design, build, and test a kinetic energy harvester for bicycles that can be used to charge common mobile devices via USB. This senior project team created a device that attaches directly to a bicycle and uses vibrations to generate energy, which in turn powers a variety of …

Parker Hannifin Chainless Challenge 2014-15 Senior Design Project, Matt Pallotta, Nathan Klammer, Kemper Whaley, Jack Rechtin

Mechanical Engineering

California Polytechnic State University has been invited to compete in the Parker Hannifin Chainless Challenge Competition in 2014-15. Cal Poly has chosen a team of mechanical engineering students to take part. We have named our team “Bike Under Pressure” and all references as such refer to the team.

The challenge is to build a bicycle which does not have a solid mechanical connection between the power input of the rider to the power output of the wheel(s). After conducting research into different previous designs and brainstorming designs of their own, Bike Under Pressure developed two conceptual designs. One design featured …

Bikeshare Business Model For Cal Poly- San Luis Obispo, Justin Benson, Andrew Neil Gatchalian

Industrial and Manufacturing Engineering

With the increasing admittance of students into colleges and universities across the nation, the need for alternate modes of transportation is becoming more pressing. College and university campuses, as well as small cities, in which there is a college or university, are being overloaded with student cars. In San Luis Obispo specifically, parking on campus as well as downtown can be extremely difficult to find. Traffic is also getting progressively worse, especially at the hour when class begins/ends and student arrive to or leave campus. Financial reasons are yet another deterrent for students at Cal Poly. Parking permits, gas, and …

Loaded Shift Tester Sram, Nick Cox, Sam Shaffer, Michael Polka

Mechanical Engineering

This report details the design, manufacturing, and testing of a loaded shift tester for the SRAM Bicycle Corporation. The machine is used to perform developmental and qualification tests on various bicycle drivetrain components. Using SolidWorks, the design team created a solid model of the machine on the computer, then ordered and manufactured the parts required to build it. The machine was tested to ensure that all the parts worked together, and was finally delivered to SRAM when it was deemed ready.

Bicycle Wheel Test Machine, Dylan Harper, Kevin Hom, Ross Williams

Mechanical Engineering

In recent years, the cycling industry has witnessed huge advancements in bicycle components and materials. The age old goals of speed and low weight are still present today, but the pursuit of these goals may be reducing the structural stability of various components integral to wheel performance, including the wheel hub bearings. These bearings are invaluable to bicycles but little is known about how the forces and loads applied to a bicycle affect the performance of these bearings. Broken axles and hubs are indicators of significant stresses within the hub, but little is known about how the resulting deformation affects …

Aerodynamic Analysis And Drag Coefficient Evaluation Of Time-Trial Bicycle Riders, Peter Nicholas Doval

Theses and Dissertations

Evaluation of drag coefficient often requires wind tunnel experiments and can be prohibitively expensive if not impossible for large objects or systems. Computational Fluid Dynamics (CFD) aerodynamic analysis offers an alternative approach and can be used as a very effective design tool in many industries: automotive, aerospace, marine, etc. The main objective of this research is to investigate feasibility of using non-contact digitizers for developing finite element models of large objects for subsequent CFD analysis. The developed methodology is applied to investigation of time-trial bicycle rider efficiency. Companies competing in this class of racing spend millions trying to optimize bicycle …

Aerodynamic Test Platform For Human Powered Vehicle (Hpv), Spencer Wangerin, Spencer Lillywhite, Colburn Davis

Mechanical Engineering

The Aerodynamic Test Platform (ATP) for the Cal Poly HPV Club is a system that was designed by Cal Poly mechanical engineering students to measure aerodynamic characteristics of a human-powered vehicle (HPV). The HPV team desired a system that could quantify the lift, drag, and other aerodynamic qualities of a full scale HPV at various orientations in oncoming airflow. Established methods for determining aerodynamic characteristics include computational fluid dynamics (CFD) and wind tunnel testing of scaled models. The ATP was devised to simulate the test results given by a full-scale wind tunnel without requiring a wind tunnel large enough to …