Hi Nicolas,

> See attached files.

Yeah it's just the problem I mentioned above, your reverse helix does not have the helix/cylinder axis positioned at the 0,0,0 world origin.

In order to simplify the script it assumes that the helix axis is on the world x axis line. That doesn't mean just in the same direction as the x axis, it means directly on the world axis line.

I've attached an update of your file where I've moved the "Not working" one so its axis starts at the 0,0,0 world origin point, does it work ok for you now? I guess it may need a negative rotation angle as well (which I see Brian notes above too).

- Michael