Subject:  [B*E*S*T]  Re: 10/16 BEST Meeting. NOTES
Date: 1997-10-22 14:52

You are all invited to come over Nov 2 for a
blitzkrieg course in "how to build an electric car". I have all the basic
tools, wheels, motors, batteries, wire, etc., and several examples of
several such vehicles. But this will be *your* project; I'll answer
questions and show you how, but I won't tell you the "right" answers or do
it for you.

I suggest that we do pretty much what the students will do. Have you seen
the movie "Apollo 13"? Remember the scene where they made an air purifier
out of a bunch of junk piled on the table? That's the idea!

1. Scrounge for raw materials

If you have some nifty tools, an old bicycle, a broken lawn chair, leftover
lumber, pipe, or house wiring, bring it along! Call or e-mail me if you
have any ideas or questions. The more we have to choose from, the better
the end result!

2. Dream up a design

Decide what we can do with the available stuff. Two bicycles strapped
side-by-side? A garden cart with a kitchen chair seat? A wooden soapbox
derby car with wagon wheels?

3. Model it

Put together a model of our intended design with Legos, Erector set parts,
cardboard, soda straws, paper clips, etc. Motorize it with a toy motor and
flashlight battery. Does it work? What problems does it reveal?

4. Build it

This will be a real "Little Rascal's" design; lots of duct tape and baling
wire. The kids have the excuse that their craftsmanship skills are
undeveloped. We have the excuse that we could have done much better but
there was no time. As in this whole project, a pretty vehicle is not the
goal; it is the learning experience that is important. You will all have
the opportunity to "do it right" with your own teams :-)

5. Motorize it

Once we have something that rolls, we can motorize it. Add a motor or two,
with some means of driving the wheels. Bicycle chain, v-belt, or simply
rubbing the motor shaft on the tire will all work.

6. Wire it

Now we add a battery, and some switches. Open and short circuits, series
and parallel, and the purpose of fuses and circuit breakers will become
suddenly clear.

7. Test it

What works, and what doesn't. How could we improve it? How can we measure
our results, so we can tell if something is better or not? Speed = distance
x time, power = volts x amps.

8. Along the way

The idea is to learn by discovery. I think you'll see that there are many
learnable/teachable moments along the way. Questions naturally occur, while
we are highly motivated to find out the answer. We'll learn how to use
simple tools. The benefits of cooperation and division of labor become
obvious. The practical applications and consequences of basic laws of
science and physics immediately stand out. When we don't know the answer,
the scientific method can be applied to find out.

Anyway, that's the plan. I'm no teacher, so please, let's hear some
suggestions on what needs to be done on that side of things. And you
designers, start thinking about what you want to build, and what we'll need
to do it!

Lee Hart