At the moment i have only worked on 1 type of droid, and it is only seen for an instant in Episode VI on the Deathstar as the Emperor's shuttle arrives, it is suspended from the rails of the hangar and looks to be some kind of maintenance droid. They were used to move ships and craft around the Deathstar using repulsorlift technology.

The model here is very basic as reference material is quite hard to hold of, but i am rebuilding it at the moment and will be re making the textures too.