building helix in 3D

I am looking at building a helix(coil shaped structure)) in 3D in Away3DLite in flex. I have 开发者_开发问答access to basic classes like cylinder, cube etc. Can I extend these to get the helix. While I understand I need to essentially increase the y dimension as the angle increases, struggling to determining how the vertices need to be defined to render in 3D

Any pointers will help... Thanks again

we managed to review the primitives already provided and charge the torus primitive to get what we wanted... wasnt too many changes

I am happy to share our changes if someone else has the same issues