Pedal Power

Pedal Power for the Occupy Movement

To support the self-sufficiency of Occupy member sites, the Pedal Power group aims to facilitate the low-cost construction and effective usage of pedal-powered electrical generators and related technologies.

The goal for this design was low cost, with most materials sourced from Home Despot and/or local hardware stores. Can be built relatively easily by anyone with access to drill press and basic tools. Circuitry includes voltage regulator ($1.50 from digikey), a few capacitors/resistors, and a diode.

Contact Info

Group email: pedalpower@mit.edu

List admin: moallem@mit.edu

(** PLEASE DO NOT RELOCATE OR RADICALLY MODIFY THIS PAGE WITHOUT FIRST CONTACTING LIST ADMIN. KTHX **)

Parts/Materials List

"A-frame" bicycle stand

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Rear legs:  TWO (2) x 20" lengths of 1" x 1" (cross-section) rectangular steel tubing

• e.g., 
• Alternatively, can use up to 2" x 1"  (cross-section) rectangular steel tubingfor added stability

Rear cross-piece(s): TWO (2) x 12" lengths of 1" x 1" (cross-section) rectangular steel tubing  

• e.g., 
• Alternatively, can use single piece of 2" x 1" rectangular steel tubing

Front legs: TWO (2) x  20" lengths of 1-inch angle steel  '

• e.g., http://www.homedepot.com/h_d1/N-5yc1v/R-202183502/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

Alternatively, can use 20" lengths of 1" x 1" rectangular steel tubing

Front cross-piece: ONE (1) x 16" (minimum, up to 30" maximum) long rectangular steel tubing, cross-section 1" x 1" (Note: If adding optional rubber feet, use longer front cross-piece for wider, more stable stance.)

Front-back connectors: TWO (2) x 20" long steel flats

[SPECIFY FASTENER HARDWARE!!! ]

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Rear-wheel (skewer) supports:

TWO (2) x 3/4" diameter (imperial size 3/4) socket cap bolts, length: 5" (Note: Can alternatively use hex-cap bolts; lower cost, but additional machining required)

FOUR (4) x size 3/4 Hex nuts

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Generator and mounting assembly:

ONE (1) x 24V DC motor (100 to 350 watt)

ONE (1) x heavy-duty door hinge

ONE (1) x strong L-bracket, at least 3" long on one side

TWO (2) x mounting plates (approx. 5" x 5", either steel or thick aluminum)

ONE (1) x roller bearings (should fit motor shaft perfectly)

ONE (1) x roller: solid aluminum cylinder, 1.25" to 1.5" diameter (Note: Can alternatively use Nylon cylinder with thin aluminum pipe as sheath)

[SPECIFY BRACKETS, FASTENER HARDWARE, AND DISTAL ROLLER SUPPORT!!! ]

[INCLUDE EXAMPLE LINKS!!!]

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Electronics:

ONE (1) xlow-voltage schottky diode

• e.g., http://search.digikey.com/us/en/products/SR1045-TP/SR1045-TPMSCT-ND/2334476
• e.g. (alt), http://search.digikey.com/us/en/products/MBR1645G/MBR1645GOS-ND/918588
• Note: Regular diode will work, but schottky diode minimizes power loss 

ONE (1) x adjustable positive voltage regulator

• e.g., 5-Amp low dropout (LDO) linear voltage regulator: http://search.digikey.com/us/en/products/LD1084V/497-3413-5-ND/669183  [LD1084V Datasheet] 
• e.g. (alt), 7.5-Amp LDO linear voltage regulator:  http://search.digikey.com/us/en/products/LT1083CP%23PBF/LT1083CP%23PBF-ND/888922 [LT1083 Datasheet]
• Note: Appropriate adjustment of maximum output voltage commonly requires several additional electronic components, as specified in voltage regulator datasheet.  For the LD1084V regulator used below, the required components are two capacitors (both 10 uF) and two resistors (120 Ω and 1.2 kΩ)