Pivot Point for the VAB Spinner-Animation

[InsaneDruid]

We all know (and hate) the fact that the MK2 Lander Can for example is spinning off-center in the VAB part selection menu.

But what excactly controls the pivot location for this spinning animation? I tried to actively re-create such an offset for learning purposes, but neither manipulating the origin of the mesh in blender, offsetting the part and the mesh in unity or offsetting the whole part in unity,  or making the mesh non-rotational-symmetric will ever force my test part to wobble in the spinner animation like the Lander Can.

Edited March 10, 2016 by InsaneDruid
typos

[Shadowmage]

I think it may have something to do with the (non-visible) ladder and hatch colliders on the side of the can -- it sticks out more than it would if it were angled (such as on the MK1 / mk1-2 pods).  Can't say I've noticed that behavior on the hitchhiker can though, so this might not explain it all.