Aircraft spinning is a rather complex motion and spins are categorized in many types based on their characteristics. Using some available data from spins executed in an instrumented CT-133, using recorded rotational rates and linear accelerations the spin parameters like radius, helix angle and related angles were calculated based on spinning analysis as described in  taking into account the CG – instrumentation offset. The position of the vertical axis of spin was then derived relative to the symmetry axis and the 1/4 wing geometric chord [x,y]. An “almost-to-scale” describing figure can be seen below.
. Phillips, W. F., Mechanics of Flight, Second Edition, Wiley & Sons, New Jersey, 2009