(FORTUNE Magazine) – Every three months David Ramsay, 38, puts in a full day on the line, working elbow to elbow with hourly employees assembling shower heads. Ramsay, who heads the biggest product line of the Waterpik subsidiary of Teledyne (No. 147 on the Fortune 500 list) has been doing this for seven years. His hands-on-up- to-the-elbows style wins high approval ratings from the likes of Bill Wheeler, a Coopers & Lybrand specialist in international manufacturing. Says Wheeler: ''There's nothing as great as a person in a position to effect change to recognize the need for it.'' Ramsay first went to work on an assembly line when, as a product manager for Samsonite, he was drafted to make suitcases during a strike. That experience gave him a worker's-eye view of production, he says. At Waterpik that view helps him improve the ways shower heads are made. An early lesson: His own sore wrists at the end of the day gave him understanding of the carpal tunnel syndrome suffered by many who do repetitive motions as part of their work. As a result, he ordered a redesign of some of the assembly equipment. Since then, lost work hours have been cut and productivity increased at the factory in Fort Collins, Colorado. Waterpik workers have honored Ramsay by naming a new machine after him. Says he of his namesake, which seals products tight as they come off the assembly line: ''I was flattered. I don't take it that it screws things down and I screw things up.''