MAG Develops Novel Process for Producing Giant Gear


As proof that it can use machine tools as well as build them, MAG has developed a process that used a horizontal boring mill (HBM) and specially designed tools to cut 588 teeth in a 19-meter (62.5 ft) diameter gear assembly weighing 60 tons (54,836 kg).

The two-piece gear assembly, made of ASTM A290 steel, consists of a 24-section track that serves as the base and a 12-section upper gear rack. The MAG team designed dedicated fixtures for each operation and special tooling for cutting and finishing the gear teeth on an HBM. “We cut the gear teeth on an unconventional machine,” according to Mark Huhn, project manager at MAG Fond du Lac. “In most cases the tooth involute would be generated by the machine itself, but we used a tool with the involute built into the cutter, which was accomplished by grinding the tooth form into the cutter first.”

The gear teeth were manufactured to American Gear Manufacturers Association (AGMA) Gear Quality No. 6, and the gear was assembled to a pitch diameter concentricity of .8 mm (.031 in). The track, comprised of A148M Grade 620-415 castings, required a special cutter to produce a 2.127-degree surface angle. “The angle was circular interpolated onto the track surface and we designed a special cutter to cut the angle on one of our gantry-type machining centers,” says Huhn.

MAG is a leading machine tool and systems company serving the durable goods industry worldwide with complete manufacturing solutions for metal cutting and composites applications. With a strong foundation based upon renowned brands such as Boehringer, Cincinnati, Cross Hüller, Ex-Cell-O, Fadal, Giddings & Lewis, Hessapp, Honsberg, Hüller Hille and Witzig & Frank, MAG is recognized as the preeminent provider of tailored production solutions based on state of the art technology. Key industrial markets served include aerospace, automotive and truck, heavy equipment, oil and gas, rail, solar energy, wind turbine production, and general machining. With manufacturing and support operations strategically located worldwide, MAG offers comprehensive lines of equipment and technologies including turning, milling, hobbing, grinding, honing, systems integration, composites processing, maintenance, automation and software, tooling and fluids, and core components. For more information please visit