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Public Health Bike Blender
The Environmental Resources Engineering Program at Humboldt State University that have been given the opportunity to create a bicycle powered blender for the Northcoast Region of the Network for a Healthy California. Team Evergreen met with Michelle Postman, a representative of the Network, to discuss and oversee the project. Team Evergreen consists of three members enrolled in Engineering 215: Carlos Carma, Jessica Bruce, and Brian Wallace.
Engineering 215 is a class that focuses on group dynamics, time management, customer satisfaction, and intricate engineering design. The class provides training in Auto CAD, Excel, Word, Powerpoint, and requires students to learn how to use a graphic design program on their own. 50% of the grade in Engineering 215 is a group design project. This page is dedicated to the project of Team Evergreen, named Smooth Ridin'. The class is given 12 weeks to complete a sixty page design document implementing the five steps of engineering design.
These design process is as follows:
- Define the Problem.
- Research previous solutions and aspects of the problem.
- Provide alternate solutions to the problem
- Choose a solution
- Design and implement the solution
Problem Statement and Criteria
Team Evergreen's objective is to design a human powered blender that is portable, practical, and efficient. The Network for a Healthy California (Northcoast Region) plans on teaching how to practice living a healthy lifestyle using physical activities.
The bicycle powered blender must meet the following criteria:
- The bike should fit on a car bike rack.
- The system should be easy to move across a parking lot.
- The blender must be in front of the operator and easy to see.
- The table should be as lightweight as possible.
- The bike must support riders age eight and older and persons up to 300 pounds.
- The seat must be adjustable.
- The apparatus must look professional.
- The bike blender must last up to five years with monthly usage.
- The design and production of the project should not exceed $325.
Description of Final Project
The final design should include:
- Cruiser Bicycle
- Bicycle Trainer
- Vortex Blender
- 56" flex shaft
- Cutting-board Table
- Adjustable Seat
- Zip ties
- Screws, nuts, and bolts
- Scrap steel
- Custom fitting for flex shaft attachment on trainer
- Custom internal shaft inside of Vortex blender
The apparatus is made from a yellow cruising bicycle that has a bicycle stand connected to the rear axle to elevate the rear tire keeping the bicycle stationary. The challenge of the design process was choosing how to get the blades to spin by pedaling and rotating the tire. A 63” Fordom flex shaft was chosen because of its ability to bend rotational energy. A flex shaft is a device that transfers rotary motion over a limited distance and bends to a desired shape. The flex shaft is represented by (A) in Figure 1. Using the back tire to provide the rotational energy minimizes the amount of alteration to the original bicycle. The flex shaft runs from the trainer apparatus to the bottom of the blender, where it is attached by a screw inside the base of the blender. The screw can be turned by one half turn of an allen wrench to remove the flex shaft from the bottom of the blender. The flex shaft is attached to the bicycle with yellow zip ties that match the color of the bicycle and keep the flex shaft away from the pedals. A bicycle trainer is a stand that holds the bicycle’s back tire elevated in the air and providing resistance for indoor exercise by pressing a wheel against the tire. The trainer needed to be modified because the flex shaft cannot reach the blender when the trainer is on the ground. The rotating mechanism attached to the trainer’s wheel in Figure 1 represented by (B) was used to attach the flex shaft. The original rotating mechanism has an axle that was attached to a large red disk, which was removed. In place of the red disk a threaded custom fitting was attached for easy setup to the flex shaft. The flex shaft is twisted counterclockwise to fit the custom fitting. The flex shaft must be aligned with the axle before it can be attached. Half of the bicycle trainer was adapted to the apparatus, which was attached to two steel frames that support the bicycle. The trainer is positioned above the tire to minimize the distance between the tire and the blender represented in Figure 1 (B). A steel stand was welded as shown as C in Figure 1, and bolted onto the original trainer’s frame. The trainer wheel that presses against the tire, (shown as B in Figure 1) can be adjusted up and down by rotating a screw with a large black handle. It can also be adjusted by pushing down on the spring-loaded device labeled (B) up and down. The blender used above the table is a Vortex Hand Crank Blender, which is made up of two main parts; the blender and the base. The base (shown in Figure 1 as D) originally contained gears, but they were removed to make room for a custom axle. This custom axle transfers the rotational energy from the flex shaft to the top of the base where the blender is attached and is one of the strongest parts of Smooth’ Ridin, because it is made of a strong metal and is protected inside of the base.
Photos and Video
Team Evergreen was able to save money through donations and finding used parts from forums such as craigslist.org. The retail costs of parts are contrasted with what Team Evergreen got to pay on the table below.
|Part||Retail Cost||Price Paid|
|63" Fordom Flex Shaft||$63.00||$63.00|
|Vortex Hand Crank Blender||$29.99||donated|
|Team Magturbo III Trainer||$270.00||$40.00|
|Bike Seat Quick Release||$4.99||donated|
The Vortex Blender, custom fittings, and the steel stands for the trainer were donated by Marty Reed (Mechanical Specialist) at Humboldt State University. The Bike Seat Quick Release was donated by the Life Cycle Bike Shop (Located in Arcata on G).
Team Evergreen put a lot of time into the design and documentation of their project, shown below a diagram (the numbers represent hours):
Discussion and Next Steps
Team Evergreen has provided the Network for a Healthy California - Northcoast Region with a product that meets goals set by client criteria. The bike blender is light enough to be lifted onto a bike rack, and can be easily transported because of the two part system. The bicycle selected was a cruiser bicycle, which is heavier than other models, so if this project was done again a lighter framed bicycle would be a better solution.
Marty Reed - Equipment Technician
Lonny Grafman - Project Supervisor
Bart Orlando - Project Consultant
Michelle Postman - Client and Representative for a Network for a Healthy California (Northcoast Region)