Hi Ryan, yeah the sweep in v2 does solve that problem and shouldn't get that kind of twisting effect in it.

It probably is a good idea to recreate the body and get it to be kind of cleaner to start with, usually if there are problems with big pieces early on it will trickle down and cause additional problems when more stuff is derived from it.

But also I've attached an new version here with just that rail curve redrawn - I did by drawing in 3 line segments, then using Blend to put in the connecting pieces (blend will guarantee a smooth piece) and then mirroring that.

If you try sweeping with this version you should get the result you were looking for I think.

- Michael