Talk:OpenSCAD User Manual/2D to 3D Extrusion

How does rotate_extrude decide which axis to rotate about by default?

The example seems to show in rotating about Z, but when I try it it seems to rotate about y. This works well for me since my profile drawing is in x and y.  Does OpenSCAD decide what to do based on the profile itself, or what?

--- Although the manual indicates that rotate_extrude cannot be used to draw screw threads, it is possible to do so with linear_extrude and parameter "twist". The trick is to get the thread profile in the plane normal to the axis of the screw (typical thread profiles are drawn in a plane of the axis). See http://dkprojects.net/openscad-threads. Dan kirshner (discuss • contribs) 17:37, 3 September 2012 (UTC)