Helix/ DNA building

I want to build a helix in my map, but I have no idea how to do this by hand( not if its to look half decent anyways), nevermind in a turtle, but I was wondering if the turtle could generate the shape for it, after that I can probably get the thing to build it itself, in layers or something, but the shape is what has me stumped, some help would be much appreciated. Or if anyone knows of one, I've seen sme good codes out there for world edit,wondered if any had been re-made or copied for turtles.

Hint for building helices: pick a small circle radius and a bigger circle radius about twice its size or larger. Then, pick two points directly opposite on the larger circle and use these as the centers of your smaller circles. For the next layer, rotate the centers of the smaller circles to the next block of the large circle. Continue doing this until bored!

Thx, took me a minit but I think I know what you mean, I'll go hunt down a circle drawing program I understand and edit that, think ill build some by hand first see what it looks like, but yh,thx alot