Glebar PG-9DHD Form Grinder Reduces Green Ceramic Scrap Rate
Glebar’s PG-9DHD Centerless Form Grinder specializes in grinding pre-sintered ceramic shafts without chipping or breaking.
Glebar’s fully automated PG-9DHD Centerless Form Grinder specializes in brittle pre-sintered (“green”) ceramics that require manufacturers to use precise and delicate processes to ensure part structural integrity. The company developed this grinder to solve problems for a manufacturer whose legacy equipment was breaking ceramic shafts and increasing scrap rates. Glebar was determined to find a solution that integrated with the manufacturer’s existing isostatic press, and that could accurately handle and grind the shafts without any chipping or breaking.
The PG-9DHD – equipped with a six-axis robot, inspection camera station, cleated conveyor and gantry – resulted from this effort. The six-axis robot sensed and transferred six ceramic shafts from the press onto the cleated conveyor. The shafts then passed through a camera station to ensure they were defect-free. Lastly, the gantry fed and removed two shafts from the grinder, reducing scrap and maximizing productivity.
The PG-9DHD removed 0.040” of stock material, 0.020” per side, while maintaining a tolerance of +/- 0.001”. By grinding two shafts every six seconds, the grinder was able to keep up with the ceramic press.
For operator safety and to achieve CE Certification, this PG-9DHD featured an enclosed grinding area and robot station.
Glebar says its machines can grind most hard-to-turn materials such as carbon fiber, fiberglass (including G10), Teflon, Santoprene and polypropylene.
Optimizing a camshaft lobe grinding cycle has traditionally been based less on science and more on educated guesswork and numerous test grinds. Now, computer thermal modeling software can predict areas where lobe burning is likely to occur, in order to determine the fastest possible work speed that won't thermally damage lobes and greatly reduce the number of requisite test grinds.
Roughing and finishing on a single machine, using a single setup, has appeal for most shops. The advantages in time savings and accuracy are obvious. Eliminating the transport of workpieces between machines, as well as the setup for those secondary operations, is a boon for throughput. Critical features that need to maintain dimensional relationships can be much more reliably produced if machined complete in one clamping.
Because of the high material removal rate creep-feed grinding can deliver in challenging materials, grinding might not be just the last step in the process—it might be the process.