try this, add attribute to your group name it RPM
if (frame == 1)
{group4.rotateX = 0 ;}
else
{ group4.rotateX += (( group.RPM * frame * 360 )/(30*60))/frame;}
just key the RPM attribute, 0 means it will not rotate.
got this stuff in highend3d.
------------------------------------------------
our decisions-not the conditions of our lives
determine our destiny.