Machine Improvements (Excerpt from June Issue of Manufacturing Engineering)
While rebuilding remains popular, new machines offer even more improvements to spindles, bases and guideways that allow machines to grind faster and to tighter tolerances.
“Our older, legacy products were built on weldment frames with cast-iron beds, which were more than adequate for the tolerances at the time,” said Robert Gleason, Vice President of Engineering for Glebar Co. (Ramsey, NJ). “As our customers pushed the tolerance envelope, we developed a line built on a granite machine bed, which gives you much better thermal stability, flatness and rigidity. Now, for the highest precision parts, we use a 6000-lb composite mineral cast base that is extremely rigid and has amazing thermal properties and excellent vibration-dampening characteristics.”
Gleason adds that Glebar often recommends double-gantry systems, which position parts in the grinder at the same time they position parts in the gages. “For example, we recently developed a turnkey package to grind a thin-wall tool steel cup. The workpiece is measured prior to grinding, ground, re-measured and inspected after grinding. That automation worked perfectly; the challenge was the grinding wheel. The tool steel cup was very springy, so without the right grinding wheel, we would have deformed the material. We found a wheel to cut the product cleanly and provide the required surface finish. As a result, our customer is making millions of parts per year at a rate of two parts per second.”