Hi and welcome!
To use Lightwave with flash you need a third party plug-in like Swift 3D, (Its a good plug-in from what I hear).
Have you seen the Mech Tutorial?
http://www.simplylightwave.com/movie...tml?tut_id=539
The Phone and the Stratocaster tutorials are very good for modeling mechanical hard very detailed objects.
http://www.simplylightwave.com/movie...tml?tut_id=538
http://www.simplylightwave.com/movie...mhtml?tut_id=7
Even though will be animating the Mech you would benefit a great deal by doing the Caveman Rigging and Animation tutorials. Animating a caveman and animating a Mech are much the same even though one is not mechanical modeling you will still be using bones for animating both.
http://www.simplylightwave.com/movie...tml?tut_id=548
http://www.simplylightwave.com/movie...tml?tut_id=549