Mechna is a planet that houses a robotics factory...
A shipment of XT4 robots was hijacked by the Legion of Darkness, who then programmed all the robots except for one to cause havoc across the galaxy. The sole XT4 robot that remained was reprogrammed by Black Phantom to be his personal assistant, and to think that he was a Hero to infiltrate the Hero Factory. Thresher and Akiyama Makuro later arrived to investigate the crash.
Mechna is known to house a robot factory from Makuro Industries which develops, among others, the XT4 robots for industrial jobs around the galaxy.