Bang Bang Kid(1967)

Guy Madison has a high old time as a would be feudal baron in the Wild West. No one is willing to stand up to Madison and his henchmen, no one that is, except mild-mannered inventor Tom Bosley. It seems that Bosley has welded together a robot gunslinger, whom he calls "The Bang Bang Kid". Only trouble is, the "Kid" breaks down at the darnedest times.