Originally Posted by SJM
The 6 footer, which I always liked the best, was used from season one to midway through season three. After that it is all stock footage.
The four foot model was made and appeared for the first time in The Defector. Surprisingly it was a very ugly shot anway. That model was then used for the rest of the shows run.
When the movie came along, it was decided that the four foot model was not sutable for movie lighting and filming conditions, so the older six footer was brought out of storage, refurbished, repainted and filmed for Generations. After filming was complete, as a joke, the model shop redid the 'D' decal so that it read 'NCC 1701 -E'.
A completely new saucer section was made just for the crash sequence, I can't remember how big it was but it was massive. They mounted it on top of a truck and drove it through a fake planet set. This worked because the whole planet set was made on top of a giant zipper. Quite cool to watch.
I remember seeing a making-of covering the crash and thinking it looked like a new model but wasn't sure.
I never really liked the 4ft model, the 6ft always looked better.