Making a cone shape

I’m interested in making a cone shape (think Dunce Cap) out of fairly
heavy gauge copper. Seems like there should be a stake that I can
form this over? So I guess I have two questions: 1) Where would I
find a stake to make a fairly large cone (6-12" tall), and 2) is
there another way to do this, other than forming over a stake?

Thanks to all!

Barb
Barbara Louise Bowling
Louise’s Leap Studios