Thanks BurrMan - That's an interesting approach to generating the sweep rails.

The "sine wave" ring is a basic one I made with CNC (see the render in the Gallery). However my MoI model is only for render purposes, not for making the ring.

To cut the channels in the ring I use a 2D drawing scaled to match the circumference of the ring. The milling machine's rotary table of course rotates the ring as it cuts. The CNC software doesn't know the servo motor is turning a rotary table and thinks it is cutting a flat 2D path. The cutting path for the sine wave is actually thousands of short straight line paths, but it all comes out smooth. Kind of like the music coming off of a CD - it's all very short 1's and 0's, but the end effect is integrated, smooth music.

I actually want to make similar engraved models using more complex shapes than a sine wave, a Celtic Knot for example. Not sure if it is possible with the current tools, but I'll try. The ability to wrap a set of curves (and also text) around a cylinder is what I need. ( No, I'm not buying Rhino :)

Earlier Michael had pointed out that Zsurf has the ability to create Nurbs from a B&W drawing and wrap around a cylinder, so I'll have to also try that.

Ed