I use ts.32 (and the word USE very loosely!

)
anyway, boot it up and load your model. It should be facing left
<--- (even though the 3d area is slightly skewed45 degrees you get the idea with trial and error where left is"
Now, if you're using 3.2 click on the icon with the angled blue boxes called "local physical attributes" you see a bunch of junk but click on the circle with the crosshairs called "Center of gravity".
Hopefully you have true view extension up and running.

the C.O.G. is selected white so move it to the center of the ship or where you want teh main hull to rotate.
Once positioned click another object like the main hull or a light then click teh model and hit save.
You have now successfully changed where the model's main geometry will rotate at... (I need a drink! Whew!)
Don;t even get me started on turrets!

If I've lead you astray one of our "experts" will be along shortly to correct my explination...
