It's just another feature of the AJS superscript. It uses sub-meshes in the bogies to swap the wheels and 'frame' around. The 'wheels' basically means anything animated, and frames is a mesh for things that aren't animated but still need to change (e.g. brake shoes). You still need a 'base' mesh with the actual animation (and at least 1 triangle) for it all to work.
I'm hoping to use a coming release as a 'demonstrator' for the way I set things up
Zec
I'm hoping to use a coming release as a 'demonstrator' for the way I set things up

Zec