rorate mesh

Hi,
I want to rotate a cylindrical mesh along y-axis. It is not rotating along axial direction but rorating some point outside the cylinder:

fix cad all mesh/gran/stressanalysis STL.stl 3 0.01 -40 -20 -50 90. 0. 0.
..
..

fix rotcad all move/mesh/gran rotate 0 0 0.0 0 1 0 0.5 cad

How to make it still( no translational motion), just rotating along axial direction?
Thanks for advising me,
Ram