"Matty F" wrote in message
...
I wish to make a large Newton's Cradle. That usually consists of five
suspended steel balls. Ideally the balls will be at least 2" in
diameter or up to 12" or 24" in diameter.
If they were steel they are likely to injure childen. So they can't be
steel. Billiard balls bounce well but are still too heavy.
Golf balls don't seem to bounce properly so they are no good, and are
too small. Soccer balls don't bounce that well either.
Polystyrene foam is too flimsy.

Any brilliant ideas? I have an idea which I will experiment with.

I think you would need to get hold of some industrial size ball bearings, 2"
plus in diameter. You need weight for inertia and hardness for bounce. Ball
bearings wouldn't be drillable so some sort of glue for attaching eyes for
suspending them would be the way to go.

mark