Machine tool 101: Part 7, Machine tools of the future

Manufacturing Engineering, Jul 1994 by Aronson, Robert B

WHAT ABOUT POLLUTION?

Over the last decade, a new factor has been added to the equipment buying equation. As a chief engineer for a Fortune 500 manufacturer said, " For many years, we bought equipment for what it would do. Today, we are more concerned about what it won't do. It won't cause us to violate water and air pollution laws or OSHA regulations. It won't encourage worker injury claims. It won't require high-tech operators or maintenance personnel."

A spin-off of the environmental regulations is a push to reduce or eliminate coolant. One approach is to live with the existing problems by enclosing the machine more securely, installing more sophisticated chip removal systems, and recycling the fluid more efficiently. Another is to go to water-based coolants and lubricants that are easier to recycle or dispose of. This is important to the machine tool designers in that they must now consider the corrosive effects of water as traditional protective oil coatings disappear.

The most radical approach is to use no coolants at all. Manufacturers will accept losses in tool life and costs for production modifications to get dry chips. In one example, diamond cutting tools used with no coolant are being considered for high-speed aluminum cutting. The advantage is better finish, higher quality parts, and clean chips (although in this case the chips are more like dust). If conventional coolants are used, the chips become contaminated and must be disposed of as toxic waste. No-coolant machining eliminates the entire coolant disposal problem and adds the bonus of chips that can be sold for scrap. Similar no-coolant operations are being researched for cast iron using CBN tools.

"There is an advantage to no-coolant, high-speed machining in some cases," says Knobeloch. "You can plasticize the materials to reduce the material's yield strength and increase metal removal rate. Coolant is a disadvantage in that case. The key is to feed quickly so the heated zone is created and cut away before the heat is transmitted to the workpiece. This is not limited to milling; it works with boring and drilling in a broad range of applications."

THE OPERATOR PROBLEM

Almost everyone agrees on the shortage of talented people. But machine tools need a new breed of generalists who can handle today's computer-controlled systems, yet readily adapt to new technology. There are several factors at work here. At the high end is the need to understand sophisticated machine tool operation plus an ability to understand computers and CAM. Some who look at all the science and math involved with some training for advanced machine tool work elect instead to go into engineering. Meanwhile, qualifications for some machines are being driven lower. Automation is limiting what the operator needs to know, and safety considerations limit what operators are allowed to do.

Dr. Richard Kegg, vice president for technology and manufacturing development at Cincinnati Milacron has similar ideas. "It will pay dividends to have a 'smart person' on the shop floor, not an untrained machine operator. The growing cost of state-of-the-art equipment escalates the cost of downtime. At the same time, shops need to maximize production. The smart person needed to run that equipment won't be the old-fashioned skilled machinist or simply a programmer. The key will be someone with the ability to handle diverse shop-floor situations, someone with broad skills who can think creatively.