Edited by Kimberley Gilles, associate editor

MTD Consumer Products now produces consistent welds on a tank reservoir for a log-splitter used by the lumber industry.

MTD Consumer Products (www.mtdproducts.com) is committed to providing quality, dependability and value with all its products, which include Cub Cadet, Troy-Bilt and Yard-Man. Part of the company's philosophy depends on its use of the latest in welding technology.

MTD Consumer Products was experiencing problems on the production welding line at its Martin, Tenn., facility. Welding done by robots on its line was inconsistent. Specific problems included slow travel speeds, spatter and poor arc starts. Michael Alexander, robotic specialist at the plant, decided to evaluate the available welding technology with an eye toward improving the quality and efficiency of the facility's production welding operation while reducing overhead costs.

The company's decision was to retrofit its robots with OTC Daihen Inc.'s (www.daihenusa.com) DP400 and DP500 digital pulse inverter welding power supplies.

Welding speeds on the first cell that was retrofitted jumped from 80 cm per minute (31.5 ipm) to 140 cm per minute (55.12 ipm), or nearly doubled on the line, after the initial setup. Subsequent tweaking of the welding parameters and other variables increased the speed to 150 cm per minute, or about 59.06 ipm.

"The retrofit transition went really smooth. The performance gained and achievement was unreal," says Alexander.

By the time production was ramped up on five retrofitted welding robots, MTD Consumer Products was able to eliminate a sixth robot. This reduced capital equipment costs. In addition, the company was able to reduce its purchases of argon shielding gas by using OTC Daihen's pulse spray transfer technology.

Retrofits such as the one undertaken by MTD Consumer Products typically involve replacing the current welding power supply and wire feeder with a new, digitally controlled welding system, and making some necessary changes to the arc welding files, says OTC Daihen. The biggest change after the initial setup is updating the arc welding software files that were previously programmed.

Alexander says the company now is considering the installation of additional welding machines.