Spring powered cannon

[jackssmirkingrevenge]

Interesting concept, but you would probably be better off using a single leaf spring from a car, cut in half. Then weld each half to a collar which would fit around a steel pipe sort of like a giant crossbow.

Sounds a bit overkill for Nerf rockets but the crossbow idea is a good one, you could have a scaled up version of what I did with this 6mm crossbow project fitted to a commercially purchased bow, it would be relatively easy to put together.