Research

 Structural Information 

Net System
   •  Rope pulley attached to rotating motor engine
   •  Lowering mechanism

Power
  Engines
   - Electric
     o Refer to http://electronics.howstuffworks.com/motor3.htm
   - Gasoline
     o Refer to http://www.howstuffworks.com/engine.htm

                            Pros                                      Cons

    Electric           -small                           -limited power output

                          -quiet                           -dangerous near water

                          -inexpensive

                          -lightweight

    Gasoline         -excellent lb/hp ratio            -costly

                          -safe                                   -possibly heavy

                                                                     -volume

                                                                     -vibrations

                                                                     -noise

Types of Electric Motors (Taken from: en.wikipedia.org/wiki/Electric_motor)

AC Induction

• Advantages: Least expensive, long life, high power
• Disadvantages: Rotation slips from frequency, low starting torque
• Typical Application: Fans
• Typical Drive: Uni/Poly-phase AC

AC Induction (split-phase capacitor)

• Advantages: High power, high starting torque
• Disadvantages: Rotation slips from frequency
• Typical Application: Appliances
• Typical Drive: Uni/Poly-phase AC

AC Synchronous

• Advantages: Rotation in-sync with frequency, long life (alternator)
• Disadvantages: more expensive
• Typical Application: Motors, clocks, audio turntables, tape drivers
• Typical Drive: Uni/Poly-phase AC

Stepper DC

• Advantages: Precision positioning, high holding torque
• Disadvantages: Requires a controller
• Typical Application: Positioning in printers and floppy drives
• Typical Drive: Multiphase DC

Brushless DC Electric Motor

• Advantages: Long lifespan, low maintenance, high efficiency
• Disadvantages: Expensive, requires a controller
• Typical Application: Hard drives, CD/DVD players, electric vehicles
• Typical Drive: Multiphase DC

Brushed DC Electric Motor

• Advantages: Low initial cost, simple speed control, (Dynamo)
• Disadvantages: High maintenance (brushes), Short lifespan
• Typical Application: Treadmill, exercisers, Auto-starters
• Typical Drive: Direct PWM

  Batteries

• Refer to  http://www.howstuffworks.com/battery.htm

Steering
   Fins vs. Shutters

                            Pros                                      Cons

    Fins                -lightweight                         -fragile

                          -simple construction             -lower efficiency

    Shutters          -better control                     -heavy

                          -higher efficiency                 -requires a frame

                                                                    -difficult construction