Machine Tool Research, Inc. (MTR), a special machinery builder and rebuilder, was recently faced with a unique problem. It had to think big--literally--when a supplier of long ship shafts for the U.S. Navy asked for its help. The supplier wanted MTR to assist in building a massive lathe--a machine for shaping a piece of material through rapid rotation along its axis while pressed against a fixed cutting or abrading tool. And it needed the shop to create the giant-sized machine quickly and affordably.

"Our customer presented a difficult challenge that meant all disciplines from engineering to assembly had to work concurrently to meet the tight schedule with a low budget," John Blawski, executive vice president of MTR, tells Modern Applications News. To meet this challenge, MTR took the working parts of several machines and pieced them together, creating a lathe that could outperform the original machines.

The Rochester, NY shop used two World War II vintage Niles lathes, integrating their bed sections in order to build a nearly 100-foot bed for the ship shafts. While MTR found two of the beds had functional hard ways, the third bed's ways were badly damaged, requiring replacement. The shop also machined all three beds to correlate on all guide surfaces for tailstock and carriage on its CNC (computer numerical control) planer mill.

For the headstock and tailstock, the shop turned to a junked Farrel lathe. MTR was able to service its severely worn headstock and tailstock, adapting them to the new bed. What's more, it achieved a 0.0002-inch TRI (total indicated runout) from both parts. Additionally, the builder completely remanufactured the carriage, creating a new cross slide with tool slides to match the work piece. To meet high precision demands, it created a twin-pinion drive for the carriage (Z axis) and a press-loaded ball screw for the cross slide (X axis).

To support the work on this two-way bed machine, MTR drafted and constructed three roller-type rests, which complied with government standards. Meanwhile, the builder found electric components for its lathe in a 1990s vintage Allen-Bradley CNC, which came from the scrapped lathe carcass. The shop then programmed the software to manage the twin-pinion drives.

So far, MTR's creativity has paid off. The machine has cleared inspection at MTR's plant and is slated for a turnkey installation.

Source:

'Monster' Lathe Built From WWII Machines
Modern Applications News, December 2004
www.manufacturingcenter.com/man/articles/1204/1204monster_lathe.asp