I'm so sorry you had trouble with the Magnetic Pendulums Snack. I will
pass your e-mail on to the Snack experts. Did you see the other
postings about Magnetic Pendulums? Here are some excerpts from some of
them which you might find of interest:
from Wed April 21, 1999:
The length of the 2x4 boards doesn't really matter. The longer boards
will just elevate the whole apparatus a little higher off the table. The
only qualification to this is that if you use 18" 2x4's, you only have
2" to play with before the hanging coils start dragging on the table!
And it's not a good idea to shorten the length that the coils hang very
much, since it's easier to observe the swinging when the length is long.
The finer the wire, the more coils you can get in a compact space, and
the less the wire weighs for a given number of coils. But the finer the
wire, the higher the electrical resistance also. For 50 turns, the finer
wire might actually be better, since the resistance probably won't be
significant for that number of turns, and you'll have less mass to get
swinging. (50 turns is essentially a minimum. A few more probably won't
from Sun Mar 19, 2000:
You need to wrap two coils of wire for the magnetic pendulums snack
(each coil with at LEAST 50 turns -- more turns should enhance the
effect somewhat). Each coil should have a hole in the middle that is
about an inch in diameter. If the hole is too big, there will be too
much space between the coil and the magnet, and the magnetic field won't
be strong enough to do the job. If the hole is too small, the coil will
hit the magnet as it swings. Ideally what you want is the smallest hole
that will allow the coil to swing freely over the end of the magnet. So
you need to find something to wrap the wire around that is about an inch
in diameter -- a one inch wooden dowel, or a D cell battery would be
examples. A cardboard toilet paper tube is almost two inches, so it's
probably a little too big -- but you might overcome that by wrapping
more turns. When you're through wrapping, just remove the object that
you you used as the core, and you'll have the coil you need. You may
want to use some tape to keep the coil from coming apart.
You need to leave about three feet of wire unwrapped on each end of the
coil, so that you can position the coils on the wooden frame and connect
them, as shown in the drawing with the snack.
> inch board is. Magnet wire is not covered so we cannot cut it. What kind of
> a lead wire with alligators clips and how long, there are several sizes.
> Also how far out of the front wood are the cow magnets supposed to go? We
> are very frustrated and disappointed on our project as we could not make it