I almost have it. I just need to calculate a theta dimension to drive my curve sweep for a flat steel coil. I have a finite length of material (L) that I need to wrap over an ID (ID). for a total revolution of (theta). I have my x & y equations for the spiral sweep:

x = ((ID/2 + pitch*(theta/(2*Pi))*cos((theta/2*Pi))

y = ((ID/2 + pitch*(theta/(2*Pi))*sin((theta/2*Pi))

I want to have a theta equation in terms of the above terms(ID,pitch,L). I'm a bit slow with my integration. Any math wiz have a second to bang this out?

Thanks,

Rod

In putting this into solidworks, I was expecting that the curve would be locked to a CSYS, or at least assume the default. I found that the resulting curve ends up not related to anything, like any other sketched entity. I wanted it locked to a csys so that I could drive an axis through the geometrical center of the coil, and to also be able to drive an offset angle for the beginning point. Hmm..