By James A. Lorincz, Editor, Tooling & Production Magazine

Grinding engineering is not a lost art. It just seems that way when you have a problem out on a machine, and there isn't anyone in the plant who really understands how to make it work right.

More and more metalworking manufacturers are learning to depend on their grinding machine builders not only for the latest in CNC technology, but, more importantly, to make sure that the machines produce good parts.

"We run the customer's parts right here and don't ship a machine until it's running their parts to their specifications," says John L. Drake, President, Drake Mfg. Services, Inc., Warren, Ohio. "I tell our people that we're the only ones who love machinery. Customers don't; they love parts out the door. That's their bottom line. A customer can't buy a machine from us just to buy a machine. It has to be a machine that produces customer parts to his requirements," he says.

Drake's GS:I (Grinding System: Internal) CNC grinders have accordingly found a ready acceptance in a variety of industries, including the automotive industry, power transmission, electric motors, and others, for bore, face, contour and taper grinding of materials from ferrous to superalloy, ceramics to exotics. Moreover, the GS:I, which is capable of aggressive grinding to tenths with feedback resolution of + 0.000 004", can accommodate high-frequency spindles with speeds to 120,000 rpm.

There's enough accuracy and performance in this machine to satisfy the demands of a market at a price (up to $300,000) it's willing to pay, Mr. Drake believes. And quality demands are becoming increasingly stringent. For one automotive company, the GS:I is running a 12-second cycle on a part with a 6 to 7 microinch finish. There are currently a half dozen of the GS:I at two different customers being used in high-production applications with auto load/unload and continuous process SPC. "Customers are becoming more demanding in their bore grinding. Parameters today include finishes less than 10 microinch, and roundness less than 50 millionths that will end up less than 20 millionths before too long," Mr. Drake says.

GS:I spindles run on hybrid ceramic bearings with through-spindle coolant flow and accept aluminum oxide, seeded gel, vitrified CBN and diamond media. All machines use motorized diamond roll contour dressing, with the wheel forms generated by menu-driven automatic cycles. In addition, the GS:I is offered with a variety of automatic front and through-spindle loading/unloading equipment, in-process and post-process gaging with SPC data acquisition and analytical display systems.

Drake has been producing CNC grinding systems for over ten years. Current production is three per month. The goal is to ship a machine that can produce customer parts from day one. One example: in its first day of operation, a Drake GS:I produced 2000 parts in a single shift. That compares with 1000 parts produced for the previous machine. "We doubled wheel life and doubled production at the same time," says Mr. Drake.