# nurbs extrusion problem

hi

i modeled a spiral using a nurbs spline as the extrusion path and a nurbs disk as extrusion profile.

the problme is that the profile somehow seems to get rotated along the extruiosn path resulting in unwanted twists!

anyone know how to fix that?

claas

If you turn on the axis display for your nurbs spline spiral you will notice that the twists occur whenever the nurrbs spline points along its own local z axis. The trick to avoiding the kinks is to align the local z axis of your spiral so that this won’t occur.

This is mentioned in the manual: