There is another kind of spring that I am looking for and I would
describe it as a "ribbon" spring, which I would use for a
centrifuge type of mechanism - not for casting of course. This is
the type of spring seen in antique toys sometimes. I've googled but
not found anything, and I even considered buying a toy and removing
the spring, but they're all very small, and what I need is bigger.
I'm sure there's something out there that is ready made. Any
suggestions at all?"
If I am picturing correctly what you are looking for, it it is a
referred to broadly as a "Clock Spring" or more specifically a
"spiral torsion spring" Do a google search on "spiral torsion spring"
and see if that's what you have in mind.