The top gaining industry for the week through Friday? Makers of automated industrial equipment. The group climbed more than 6%, bringing its year-to-date gain to 37%. Eight of the group's 10 stocks are thinly traded. The two with healthy volume, Stratasys (SSYS) and 3D Systems (DDD), manufacture tools called 3D printers. Initially used primarily for making prototype models, the machines are rapidly finding innovative applications. Unlike laser