Re: Instantaneous radius of a rotation

I guess you want the "extrinsic curvature" of a space curve. That
should point you in the right direction.

Thanks for the tip. Actually I was aware of this formula but not in the
concept of this study.
(http://en.wikipedia.org/wiki/Curvature#Curvature_of_space_curve)

This helps me find the radius. According to my tests, this formula is
producing correct results.

Next question I need to answer is the vector pointing to the center of
instantaneous rotation to find the direction of the centrifugal force.

.