Geared-up Final Design Labeled.jpg
FA info icon.svg Angle down icon.svg Project data
Authors Jenna Bader
Dashiel Bivens
Team U^s
Completed 2011
Made Yes
Replicated No
Cost USD 407.59
Instance of Pedal powered generator
OKH Manifest Download

This page represents "Team U^s's" bike-powered energy project for Flock House. "Team U^s" is a group brought together through Engineering 215 Intro to Design, taught by Lonny Grafman at Cal Poly Humboldt.

Introduction[edit | edit source]

Flock House[edit | edit source]

As urban populations continue to grow at exponential rates, sustainable living practices must progress to meet basic human needs. The need for sustainable living practices inspired our client, Mary Mattingly, to create the Flock House mobile art project. Evolving beyond the limits of the typical urban development, Flock House pods have the capability of migrating and inhabiting any unused space. From the sides of buildings to sidewalks, the exact location is only limited to the imagination. The "Flock Pods" are intended to be renewable homesteads. Most food and energy needs will be generated through the "Flock Pods" internal system, and the rest through community support. To meet the energy needs of the inhabitants, each pod is geared with a bike powered energy source (Geared Up From the Feet Up), and a Flock House Handcar Generator. Launching on May 1st, 2012, the first Flock House pod will move through New York's Lower Manhattan neighborhood (view the entire schedule).

To learn more about the project you may visit the Flock House web page, and for more information on the other projects incorporated in Flock House visit the Appropedia web page.

Team U^s[edit | edit source]

Team U^s consists of four students: Jenna Bader; Dashiel Bivens; Jacob Rowe; and Karen Stufkosky, enrolled in Cal Poly Humboldt's Engineering 215 Intro to Design taught by Lonny Grafman. The team was challenged with the task of developing a bicycle powered generator capable of generating 100+ watts while enabling the use of all types of bicycles. This project is intended to increase the general public understanding of renewable energy and allow for any cyclist to take part in generating energy.

Problem Statement & Criteria[edit | edit source]

Criteria Weight Description
Power Output 10 Must generate at least 100 Watts
Ease of Use 10 Simple to set up

Fits all bicycles with 25-29" tires Rider can generate power for 20 minutes

Consistency 9 Works every time
Durability 8 Must withstand the weather and daily use
Portability 7 No more than a single person needed to move
Aesthetics 6 Visually appealing
Safety 5 Safe for rider to use and bystanders
Cost 5 Does not exceed budget of $375.00

Problem Statement[edit | edit source]

The Flock House needs a power source that is easy to use for all ages, accommodates most varieties of bicycles, educates, and is able to generate enough power to meet the needs of the two inhabitants.

The Objective[edit | edit source]

The objective of Team U^s is to design a portable, detachable, and re-creatable bicycle-powered generator using recycled materials for Flock House, the meta-project. If possible, multiple bicycle docks would be connected to power the Flock House pod for its inhabitants and to use as a learning tool to educate visitors about alternative energy generation.

Geared-Up From the Feet-Up[edit | edit source]

fig 4:Final Design CAD (By Dashiel Bivens)

Cost and Materials [edit | edit source]

Geared-up Finalhoursus.jpg
Material (Your Cost) Quantity Cost
Charge Controller 1 $111.54
Trainer Stand 1 $67.35
DC Motor 1 $63.08
Bicycle Pedal Crank Arm (seek used if possible) 1 $25.00
Plexiglass (4 pieces) 1 $20.00
Extension Cord (25 Feet) 1 $14.84
Plexiglass 1 $13.88
Bicycle Pedal (seek used if possible) 1 $9.99
Derailleur 1 $9.99
Heat Sink 1 $9.99
BMX Bike Chain 1 $9.98
Bike Sprocket 1 $7.66
Blocking Diode 1 $6.98
Light Bulb Socket 1 $6.00
Hinges 2 $5.99
12 Volt Light Bulb 1 $5.84
Cabinet Magnet 2 $4.00
Wire Connectors 2 $4.38
Chain Lubricant 1 $3.49
Fuse Holder 1 $2.19
Scrap Wood (seek recycled pieces) 4 $2.00
Square Bolt +Washer +Nut 1 $1.69
Scrap Metal (From scrap yard) 6 $1.00
Fuse 1 $0.73
Total Cost $407.59
Material (Our Cost) Quantity Cost
Charge Controller 1 $111.54
Trainer Stand 1 $67.35
DC Motor 1 $63.08
Extension Cord (25 Feet) 1 $14.84
Plexiglass 1 $13.88
BMX Bike Chain 1 $9.98
Bike Sprocket 1 $7.66
Blocking Diode 1 $6.98
Hinges 2 $5.99
12 Volt Light Bulb 1 $5.84
Wire Connectors 2 $4.38
Fuse Holder 1 $2.19
Square Bolt +Washer +Nut 1 $1.69
Fuse 1 $0.73
Derailleur 1 Donated
Cabinet Magnet 2 Donated
Plexiglass (4 pieces) 1 Donated
Heat Sink 1 Donated
Bicycle Pedal Crank Arm 1 Donated
Bicycle Pedal 1 Donated
Light Bulb Socket 1 Donated
Scrap Wood 4 Donated
Chain Lubricant 1 Donated
Scrap Metal 6 Donated
Total Cost $316.13

Final Design[edit | edit source]

Geared-Up From the Feet-Up is designed to power the Flock House efficiently with the highest power output possible while still being simple enough for most riders to generate power.


This design is built using an adjustable bicycle trainer stand, a DC motor, a charge controller, BMX bike sprockets, a single-speed BMX chain, a derailleur, and electrical components necessary to power a 12 volt battery all enclosed in a plexiglass box.

Mechanical System

Mechanical System (Photo By: Jenna Bader)

The cyclist locks the rear-wheel axle of their own bike into the bike stand by rotating the knobs on the side of the stand. The bike stand can accommodate most bikes with a rear axle diameter of less than 8 1/2" and tire sizes between 25"-29" in diameter by means of an adjustable roller below the bike tire.

The roller rotates a single-speed bike chain which is attached at the end of the roller and then to the motor. Because the stand is adjustable to different tire diameters, and our motor is screwed into place on a base board, it is necessary to use a tensioner its job. We repurposed a used derailleur to act as a tensioner for the chain. This adds ease of use to the system.

Electrical System

Electrical System (Auto CAD By: Karen Stufkosky)

The electronics used in the Geared-Up design are a 36 volt DC motor, a 15 amp fuse and fuse holder, a 40 amp blocking diode, and a 12/24 volt charge controller all wired in series to a 12 volt deep-cycle battery using 12 gauge copper wire. There is also a 12 volt DC light bulb screwed into a light socked which is wired in parallel through the charge controller, used to expend our excess load from the charge controller after charging the battery.

The charge controller was a necessary component in our design because we had to ensure a happy battery that will be charged continuously to power the Flock House. Deep cycle 12 volt batteries like the one we used, like to be charged at a constant input of 13-15 volts. If an eager rider generating power on our system were to produce more volts than the charge controller is set to, the light bulb will start to light up. Optimal battery charging occurs at a "sweet spot" where the rider can constantly pedal their bike easily, and the light barely flickers. This flickering light means that the battery is being charged at 13 volts and you are barely generating an excess amount of wasted energy beyond that limit.

The blocking diode ensures the direction of electrons flowing from the generator to the battery, rather than electrons flowing from the battery to the motor when a rider stops pedaling. The diode is rated at 40 amps ensuring optimal safety to the rider because our motor is only rated at 13 amps.

In case of electrical mishaps, the 15 amp fuse will likely blow. This ensures safety to our system and to any persons around the electrical components.

Results[edit | edit source]

The final design of Geared-Up From the Feet-Up had a variable energy output range. A person riding on the bicycle for 5-10 minutes can produce power ranging from 50-140watts depending on the fitness level of cyclist.

During our development process, several issues arose that increased the complexity of our final design.

  • The rear bicycle tire must have constant tension against the roller. If the roller was not tight enough against the tire, the roller would burn rubber from the traction caused by slipping. With the roller pressed hard into the tire, the friction was minimized and the powering revolutions of the roller were maximized.
  • The custom designed gear system was hard to test because so many pieces were variable. The BMX sprockets had to be custom fit to our roller and motor each time in order to test the appropriate gear ratio for the system. This was a difficult phase because each sprocket had to be welded to a custom-fit piece of steel in order to attach to the rods.
  • The electrical circuit needed to be set-up in a way that the electrical components would not overheat.
  • The bicycle stand had limitations that we had not foreseen. The stand works well for a range of tire diameters because it is widely adjustable at the roller base. However, the width of the axle locks are limited to a small range of rear wheel axle diameters up to 8 ½ inches wide. We did not anticipate the wide variety of styles on bicycles including modern quick release tire mounts and bulky accessory customizations like bag holders/baskets.

Discussion[edit | edit source]

DIY[edit | edit source]

For Details on how to build your own How to build Geared-Up From the Feet-Up <----click the link

Special Thanks[edit | edit source]

Check the website out!

Authors[edit | edit source]

Jenna Bader | Dashiel Bivens | Jacob Rowe | Karen Stufkosky

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