extruder screw

[uwam2ie]

I'm fighting to build an extruder screw. I have used a helix curve and a simple rectangular sketch in a swept with the forced direction option but the result is poor. Any ideas how to create the screw?
thx in ad

 

[cowski]

Use vector direction and choose the axis of the screw as the vector.

 

[mmauldin]

Also, make sure "Preserve Shape" is checked.

 

[uwam2ie]

thx on reply,
I have tested and found an other way, I have attached the file NX6, maybe more experienced extruder designers give tipps or an alternative solution.
thx in ad