Why extrude does not follow the curve? Here's a short video http://take.ms/cv1Ko [take.ms]

It doesn't work that way. Extrusion is in a local space, the curve's z axis is used for the extrusion in the face's normal direction. Curve displacements in x and y are in the local tangent space of the extruded elements.

Try drawing your curve starting from the origin and tangent to the z axis before deviating.

jsmack
It doesn't work that way. Extrusion is in a local space, the curve's z axis is used for the extrusion in the face's normal direction. Curve displacements in x and y are in the local tangent space of the extruded elements.

Try drawing your curve starting from the origin and tangent to the z axis before deviating.

Is that supposed to work like that? http://take.ms/FBs4n [take.ms] Geometry does not lie exactly along the curve

Yes, that is how it is supposed to work. The extrusion is in a local relative space. The absolute position and orientation of the curve is irrelevant.

For more direct control by the curve on the output, a sweep operation is more applicable.