| Intermediate Technology Education | Energy and Power Technology | Design Stage 2 | Topic 6 | Optional Activity 5 |

The Miller Engine

Construct a Solar Racer

You will need

  • Miller solar engine with pager motor and wheel
  • Small set of wheels and axle (Lego?)
  • Foam core board or thin, stiff cardboard or plastic
  • Double sided foam tape
  • Hot glue gun
  • Incandescent lamp (or sunlight)

Pre-Assembly Chores

  • Cut a rectangle from a piece of foam core (or stiff cardboard) about 10 x 6 cm.
  • It is assumed that the Miller solar engine is assembled and tested. Also the small wheel should be mounted on the motor. This is done using a piece of insulation stripped from a small wire which is pushed over the motor shaft.
  • Also you may have to extend the wire connecting the motor to the solar cell if you find it too short. Make sure you insulate the splices. (If you need a refresher on splicing wires, view the video included with your resources.)
  • You will need a small block of wood or plastic to mount the motor. The size will depend on the wheels and axles you have (you can raid the lego box or de-construct a small toy).

Assemble the Racer

  • Start by attaching the front wheels using double sided tape or hot glue. You make have to notch the foam core depending on the length of the axle. Be creative!

Figure. Underside of vehicle showing pager motor and wheel

  • Next, attach the motor and drive wheel using tape or hot glue. The center of the drive wheel should be exactly centered on the foam core. Again, the size of the wood/plastic mounting block will depend on the front wheel size.
  • Next, attach the solar cell / circuit to the top of the racer using tape.

Figure. Topside of vehicle showing Miller solar engine

Full Impulse, Mr. Sulu

  • Place the assembled racer under a bright, incandescent light (fluorescent lights will not have enough energy). Do not place it too close or it may melt the plastic coating on the solar cell. Use the floor to give the bot room to move.
  • Depending on the size of the power storage capacitor on the Miller circuit it may take a minute or two to charge.
  • What happens when it charges?

Make appropriate entries in your module portfolio.