Home >> Research >> Human Powered Machines >> ESLP 2007 ART >> Meeting Minutes

Week One April 8, 2007


Tim, Josh, Tai, Alec, Arlen, Jason

Campus human powered machines brainstorming session:

  • Washing machine (domes, tri-coops, dorms, laundry facilities)
  • Plot plow (student farm, EC gardens, domes, tri-coops)
  • Water pump (student farm, EC gardens, domes, tri-coops, grounds)
  • Roto-tiller (student farm, EC gardens, domes, tri-coops)
  • Kid powered carousel water pump
  • Carousel (Orchard Park, Solano Park)
  • Pedal powered desk: laptop, ipod charger, etc (classrooms, student lounge, dorms, Bike Church)
  • Giant salad spinner/greens cleaner (student farm, ec gardens)
  • Food processing: nut shellers, butter makers, oil press (student farm, EC gardens, coffee house)
  • Ice cream maker (coffee house)
  • Fabrication equipment: drill press, saws, lathes, grinders, sanders (craft center, domes, student farm, machine shops)
  • Pedal power exhibition: demonstrates pedal at fairs, festivals, etc (picnic day, whole earth)
  • Mobile radio station (KDVS)
  • Pedal powered pickup truck (TAPS, grounds, project compost, R4, Bike Church, Student farm, bike barn)
  • Bike pumps: air compressor (Bike barn, bike church)
  • Bike wash and lube (bike barn, bike church)
  • Car sized human powered vehicle
  • Mobile bike rack: for bike parking at events (whole earth, picnic day)
  • Human powered bus
  • Heavy duty trailers (TAPS, grounds, project compost, R4, Bike Church, Student farm, bike barn)
  • Party bike/Keg bike w/ keg charger
  • Parade vehicles (KDVS, Bike Church, Whole Earth, Project Compost)
  • Billboard vehicle
  • Pedal power demonstration at admissions/entrance office
  • Dishwasher (Coffee House, Whole Earth)
  • Edge trimmer (grounds)
  • Compost turner (Domes, Tri Co-ops, Project Compost)

Interview Assignments (due Sunday April 15):

  • Matt: Domes, Student Farm
  • Arlen: Tri-Coops, Coffee House, Aggie Pack
  • Tai: EC Gardens, Project Compost
  • Josh: Bike Barn, Grounds, R4
  • Tim: TAPS (David Takemoto-Werts), Craft Center
  • Ted: Whole Earth

Sign up for these other places: Picnic Day, Campus Center for the Environment, ASUCD, KDVS, Student Housing

Contact someone at these various on campus facilities and see if they would be interested in pedal powered machines.

Possible questions to ask:

  • What low power tasks to they perform?
  • Would they use a human powered version if available?
  • What machines do they have that could be converted to human power?
  • Do they perform any human powered tasks already? Is it efficient?
  • Would they be willing to help fund the project?

Human powered machines around town (let's contact these people!):

Second assignment (due Sunday April 15):

Find two human powered machines, learn how they work, and share them at the next meeting. A picture or diagram may be helpful.

Week Two April 15, 2007


Ted, Matt, Alec, Jason, Josh, Tim, Arlen

What machines did we learn about?

  • Jason: Shared various machines out of the books Bicycling Science and Pedal Power
  • Arlen: Coffee grinder, Laptop charger, Retro-direct drivetrain
  • Ted: Cargo bikes
  • Josh: Generators, chargers

Campus interview results:

  • Tri-Coops: coffee grinder, any of the machines that we though of would be useful, they may be able to provide some funding, they need a blender that can crush ice
  • Coffee house: there probably wouldn't be room for the food processing machines, but they are interested in the charging desk
  • Grounds: One electrician's response to whether he would be willing to use a pedal powered truck was "hell no!"

New ideas:

  • ARC demonstration on collecting energy from the machines to power the lights or add energy back to the grid
  • Aggie pack soft object shooter

Top 5 Machines (we will choose one next week):

  • Charging desk
  • Washing machine
  • Trailer/Hauler/Pickup truck
  • Kid powered water sprayer
  • Plow

Possible additional machines that we can build:

  • Salad spinner
  • Coffee grinder
  • Compost turner

Assignments (due next Sunday):

  • Find critical components for the top five machines. Depending on what we can find will help us decide which machine to build.
    • Things to find:
      • Exercise bikes
      • fly wheels
      • Inverter
      • Batteries
      • Washing machine
      • containers, tubs for hauling bikes
      • plow
      • winch
      • valves, water tubes
      • coffee grinder
    • Places to search:
      • Craigslist - look in the free section, post wanted ads, also check the for sale areas (we will try to find money for the parts)
      • Freecycle - post wanted ads and search the list
      • Dumpster diving - Davis Waste Removal on second has a metal dumpster
      • Ask businesses for donations
      • Landfills - Matt work at the Yolo landfill and may be able to help us get access
      • Machine parts - McMaster Carr
      • Bargain Barn
      • Thrift Stores
  • Find out who else has built similar machines. If you can find plans get copies. Learn how the other machines worked or why they didn't work. Contact the inventors and see if they have any tips. Send web links to the list serve (pedalpower @ so we know what has been found.
  • Contact any of the campus groups that you didn't talk to the first week
    • Ted: Whole Earth, Project Compost
    • Matt: Student Farm (salad spinner guy in the shop)
    • Arlen: EC Gardens, Aggie Pack
    • Josh: Bike Barn, Grounds
    • Tim: TAPS

Week Three: April 22


Matt, Jason, Alec, Josh, Robbie

New findings:

  • Matt: The student farm needs a giant salad spinner and a way to transport stuff around the farm grounds. They would like to have a pedal version of a john deer mule. They have a large stainless steel colander for the salad spinner.
  • Alec: The student farm will most likely provide a space for us to work. We will need to take their safety orientation before we can use the facilities. Currently the shop is only open 4 days a week and possibly limited hours. There are a bunch of plows that could possibly be used for a pedaled version.
  • Josh: Josh's dad has some inverters that we may be able to use. Josh and Tim checked out the prices of inverters at Fry's and found them to range from $30 to $100 depending on quality and wattage ratings.

Other stuff:

  • Alec shared some information on velomobile design.
  • Should we start a club similar to the Antique Mechanics club, where we could continue to build pedal powered machines?
  • We could invite local (and non-local) pedal powered enthusiasts to show off their machines.


  • Campus sustainability grant (due April 27th): This has been applied for once, but needs to be reworked and resubmitted.
  • ASUCD: We need to send someone to a meeting an request funds for the desk
  • GSA: They have a projects fund that we can apply for.
  • PUFF: Presidental Undergraguate Fellowship or something.
  • Coffee house: can they provide funds directly to us?

Time to choose one machine:

After the weighing of the pros and cons of the top 5 machines we decided on the Pedal Powered Desk/Charging Station for the coffee house! The reasons were because it is a multidisciplinary machine with a good combination of industrial, mechanical, and electrical design and will be seen by more people than the other machines.

Design Criteria:

We spent time developing a well-defined set of design criteria for the pedal desk. These will keep the team on the same page and allow us to narrow down our search for design solutions.

  • power at least one laptop (more devices if possible)
  • exhibit uses of pedal power (signage, posters)
    • We should make this a learning experience to let people know what, why and how about human power.
  • space for laptop, notebook, coffee, donut
    • This should be a functional desk that has room to hold the things you normally use at a desk.
  • adequate pedaling space
    • the leg room under the desk should be a sized for all kinds of people. We don't want any busted knees.
  • adjustability for different sized people
    • Leg length for different people and chair height should be addressed.
  • comfortable for 30min to 1 hour
    • The user should be able to "ride" the machine comfortably for at least one hour.
  • have to pedal or power doesn't come on
    • To prevent folks from just using the energy stored in the batteries without adding any back to the system.
  • displays for charge level, cadence, some way to know you are producing enough power
  • displays for: instantaneous, overall for machine life
    • What amount of power are you producing? How much power has been produced over the machines entire life?
  • equivalent energy output
    • how many hamburgers did it take to produce that energy? How many pounds of CO2 did you prevent from joining the atmosphere? This can be shown in the signage.
  • signage: how much reusable materials
    • Show how free and reusable materials can be used to make a quality machine.
  • fit through doors
    • We must be able to bring the desk into buildings. It may need to be able to separate into smaller pieces.
  • attractive, aesthetics, nicest table in the coho
  • needs to be quiet
  • needs to be safe for the user and surrounding people
  • burley
    • should withstand abusive use from college students

What information do we need to know to make the initial design decisions?:

  • How much power does it take to power a laptop?
    • Tom Denton built a super low power computer. He may be a good person to get some info from.
  • How much power can one person produce?
  • What is adequate pedaling space?
  • What is appropriate pedaling position?
  • What is the max power to request from one person for a 30-1hour period?
  • What is the surplus charge that we can create?
  • What parts and where to get them? (inverter, generator, wood, gauges, leds, pedals, char, etc)
  • What are the subsystems? (ergonomics, mechanical, electrical)

Subsystem teams:

We are all going to work collaboratively on the design of the machine but we decided to divide the group up into sub-teams so nothing gets neglected and there are folks that will be responsible for each part of the machine. The groups will need to communicate well with the other groups, because design changes in one group will almost always affect the other groups' design.

  • Ergonomics (Josh, Alec): seating position, desk design, signage, aesthetics, adjustability for size of rider
  • Mechanical (Matt, Jason): pedal mechanism, mounting for the components, provide mechanical energy in appropriate form for the electrical components
  • Electrical (Robbie, Tim, Arlen): convert mechanical power to electrical, store the energy, make lights and guages, choose appropriate components: dc generator, inverter, batteries


  • Answer the design questions that are appropriate to your sub team (look at list above for ideas, we will need concrete numbers)
  • Everyone should come to the next meeting with well defined design ideas (i.e. sketches, calculations, etc)
  • Continue looking for components: the faster we find what we need the more defined the design will become.

Week Four: April 29


Alec, Robbie, Tai, Jason, Matt


Andrew Peake from the ASUCD visited us and likes our idea. He is willing to help us get funding and find a place to put the desk. He suggested we come pitch our idea to the EPPC committee because they may have some funding. Arlen agreed to go give them a short schpeel on our project. Andrew also told us to contact Sharon Coulson the director of the coffee house. She will be able to give approval on putting the desk in the coffee house.


Tai led the team in a design session. We began by sketching individual ideas on large sheets of paper and hanging them aroudn the room. Each person then described their designs to team. After this we picked a partner and came up with design that encompassed what we liked best in the previously presented ideas. Finally we attempted at merging the final designs into one final design to work from, but this didn't quite happen and left the design undecided.

Notes from Alec on design:

We talked about a lot of good things at the meeting yesterday- hard to
summarize but I think we want to mock up a machine and produce power
with it to tell us:

a) that we can build a machine such that it will produce the amount of
power we want without the user getting such a workout that they feel
like they are in the ARC.

b) that while producing this power you could possibly simultaneously
use a laptop- this question bears on the position of the rider/diner.
A fundamental design bifurcation was uncovered yesterday, between the
machine as primarily a table, and the machine as primarily an
"efficient" power-generating unit that looks from 100 yards away like
an upright exercise bike or like a recumbent bike with a workstation
floating above it.


- test seating/typing positions for comfort, efficiency, quietness, nonwiggle,etc and come to a final decision on the configuration
- test out a generator to see how much power is produced in different configurations
- take a look at the exercise bike Alec recovered and determine how or if to use it
- some talk about the signage may be good (make a list of ideas and sketches). This will be helpful to get funding

Week Five: May 6

No meeting but some work was done at the shop. Tai's notes follow:

-The Cateye is disassembled down to the functional pedal unit and on the table.
-Jeff and I cleaned up the space
-We will need an adapter to mount an alternator or generator out of the pedal swing
-there are four main components rotating in the system:
--the 60 tooth (or so) chainring (singlespeed chain)
--a jackshaft with a freewheel on one side and a toothed belt gear on the other
--the resistance wheel from the toothed belt, which also has a smaller, untoothed belt
--flywheel connected to untoothed belt

we may want to pull out the jackshaft, resistance wheel, and flywheel. use the jackshaft location to put in a second chain gear, and drive a generator (mounted outside of the box) with that. We would be able to get about a 8 or 10 to 1 gear ration with that system, meaning that we could drive a 400rpm motor. if we need higher rpm, we would need a second jackshaft mounted where the resistance wheel or flywheel currently are.

The setup is possible to rotate 90 degrees to then become more appropriate for the vertical configuration. all we would have to do is mount the seat by it's back, rather than it's seat, and we could use all the same components (at least to test it).

The bolts I took out are on the table next to the plastic covers.

Week Six: May 13


Jason, Robbie


Nothing really.

Week Seven: May 20


Alec, Josh, Matt, Tai, Jason

Connect the generator:

  • Belt drive
  • A sheave will be constructed Monday for a 45 rpm cadence and 260 rpm motor speed and left at the shop
  • Plywood base to attach the pedal station and the motor. The motor will be mounted on rails to adjust tension
  • We need a flat belt that will fit the flywheel


  • Alec has a desk that we can use for basic mock-up


  • We discussed ideas for the poster design


  • Fabricate sheave (Jason)
  • Bring desk to student farm (Alec)
  • See about weekend access (Jason)
  • Find a belt for the flywheel to motor connection (Matt)
  • Work on poster (Matt, Josh)
  • Fabricate rails for motor mount and deliver to the shop (Josh)
  • Deliver a piece of plywood to the shop for the base (Josh)
  • Drop off cadence meter (Alec)
  • Get a 12 volt auto style female plug (Matt)

Other things to think about:

  • Do we need a battery? If so see if we can find one.
  • Do we need cadence or voltage read out to help regulate the pedaling?
  • Do we need a fuse so we don't fry the computer?

Week Eight: May 27


Robbie, Jason


Worked on the pedal desk at the Bike Church:

  • attached motor,
  • added a better seat
  • built adjustable desk
  • tested output wattage: