Aging grinders at Timken are now flexible and set up fast thanks to retrofitted GE Fanuc Automation controls.
It was time to rebuild aging grinders at Timken's Rutherfordton, N.C., plant. Machine controls were dated, programming code was cumbersome, experienced service suppliers were few and far between, and maintaining a large inventory of spare parts was costly. With a need for greater flexibility and faster setups, the plant, which manufactures precision and commercial ball bearings and self-aligning spherical plain bearings, wanted to replace old controls with new off-the-shelf components and swap manual systems for electronic ones.
After successfully rebuilding its first grinder using an off-the-shelf motion-control system from GE Fanuc Automation, Timken tackled seven more machines, which originated from five different manufacturers and had two or three axes of motion. As a result of the rebuilds, setup time dropped more than 50%, machine maintenance decreased as much as 60%, spareparts availability improved, and operational-efficiency rose.
Timken installed GE Fanuc Series 90-30 PLCs with SDM314 motion controllers, Alpha Series servos, and rugged PAC-OP industrial computers as well as, in one case, an S2K servo amp. With a turnkey package on the panel and backplane, the rebuild team simplified the process, from tearing the machines apart to replacing coolant lines and solenoid valves to fabricating new doors for increased safety.
"Essentially, we gut our early vintage machines down to the castings and make them more precise, faster, and easier to operate," explains John McMillan, senior project engineer at Timken. "We've replaced control panels that had several hundred relays and are doing things most consider impossible with a PLC-based system."
Since the rebuilds, Timken has also shortened operator training by over 45% because controls are common and settings are automatic. The company also nearly eliminated hydraulic-system components for a savings of $1,800/yr on hydraulic oil, while increasing overall part quality.
"In a Six Sigma study we verified our accuracy by comparing a rebuilt machine with a high-end one less than five years old," says Dave Mow, a controls engineer with Timken.
"The rebuilt machine outperformed the newer one in 100 moves, and we discovered that the attainable accuracy is excellent with no lost motion and tremendous repeatability — all based on the fact that the machine is tight and well controlled."
GE Fanuc Automation Americas Inc.