when doing a 3dspiral in 3d space in autocad by lisp the 3dspiral is made by a bunch of 3dpolylines. when i go to extract an object by path it rotates along the 3dspiral. that is a problem cause by some default acition it must be perpendicular to some plane (as i understand). basically i can not make a screw in 3d space because when i want to subtract the 3d spiral from the cilinder (which represents the body of the screw) the 3d spiral is all twisted. of caourse if u didn't extract by path a circle (the rotation is present but not significant because of the unique shape of the circle :-)) but in truth that is not the proper look of the screw.... help would be appreciated tnx
