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Group 13: Rowing bike redesign

Abstract

The rowing bike project is four wheeled bike that is powered by rowing the handle bars.  Melissa Draper of Cookeville High School has requested that this bike be made for all children but specifically children that may have trouble with balance or using their legs. The bike’s intention is to fulfill these requirements and provide fun and exercise for anyone.

Seal Team 13: Matt Bolden, Caleb Fish, Thad Simerly, Tyler Seal

Problem Statement

The rowing bike when received did not have functional steering, made grinding sounds inside of the gearbox, and did not move forward when the rowing handles were pulled or pushed. This bike was not functional.

Design Specifications

Requirements for a finished product on the rowing bike are be able to move when rowed. It is preferred that the bike have a good balance of input at the handle bars to output at the wheels so that kids of all strengths will be able to use it. Steering is preferred but not required along with brakes.

Background Research

Our group did research on the past groups that have worked on this rowing bike and talked about why that group’s design worked or why it didn’t. We also researched rowing bikes of many different types manufacturers to help find design input.

Concept Design 1

Our concept 1 is to take the current (non-functioning) design of the rowing bike and make it functional by making the steering work and improving the gear box design by redesigning the slot that the float gear sits in and replacing several components to make the past group’s design work.

Concept Design 2

Our concept 2 is to redesign the entire bike using the pros and cons of the current bike as a basis for building a new one so that we can more easily make improvements without major and time consuming modifications to the current bike. This style would be similar to a steam engine with a ratcheting wheel at the rear axle for safety. This design would drastically decrease the room for error on this bike by turning a complicated, non-working design, into a simplistic working design.

Concept Design 3

Our concept 3 involves a one directional ratchet design. This will be attached to the existing bike frame and axel. This will allow for the user to still have the ability to row the bike like the original design. This design though is simpler and more time and cost effective. There are overall less parts that will have to be designed.  The existing bike may have to be modified in order to house this new assembly.

Selected Concept Design

We selected concept design 1.

Overview of Selected Design

The decision of choosing a option to run with for the redesign was a tricky one. There were many components that had to be considered. Some of these included the simplicity and ease of operations that would have to be accounted for while doing this. One of the major things that we considered here is availability of time. We are all hoping to be engineers one day, which means that we all have complex schedules that do not line up very well, so we had to understand that a lot of the tedious work here will have to be done remotely, but at the same time as a group we will all have to work together to get this project done on time. Which is why we chose to redesign the existing gear box. By doing this the team feels that we will have a cost and time effective manner to meet the project deadline. We already have broken down the problems of the bike in its current state have have designed a attack plan.

Engineering Analysis 1

The goal here was to check and do calculations on previous assumed steering column inputs to check for the resulting angles.

Engineering Analysis 2

Here we made our modifications to the existing gear box and discussed the problems with the previous groups.

Engineering Analysis 3

In this analysis we discuss how to fix the steering design. We simply will modify the existing steering by changing some of the existing components.

Bill of Materials

Instructions for Safe Use

Sit in the seat with your seatbelt on and place your feet on the pedals.  Then grab the handle bars with both hands and slowly pull back.

Semester

2021 Fall