The R4-19 works on the Death Star in the hangers, repairing and maintaining the various TIE vessels that dock. In the logic unit is housed a magnetic fault sensor and circuit detector. Due to security reasons the droid has limited perception and is only permitted on the hanger deck.
sweeeeeeet, its an r4 unit! inginous way of making the legs. they made an all black r2 unit for the minifig size star destroyer set. that coult certainly improve on this, if you wanted to spent the money for it. nice job dude, i love astromechs!