FX-6 Medical Droid BD28, includes droid factory part.
Source: Revenge Of The Sith
Can be seen when Darth Vader is given his armor.
FX-6 is one of the medical droids that assist in the reconstruction of Darth Vader after the Sith Lord’s devastating duel with Obi-Wan Kenobi on Mustafar. The droid has multiple arms equipped with a variety of medical and diagnostic tools.