Machine OEMs Meet the Moment
Artificial intelligence and automation help modernize machining
As the manufacturing world transforms outside the machine shop, things inside need to change as well. So machine tool suppliers are doing what they can to help shops adjust to the latest production requirements and economic considerations. In addition to upgrading technology in a variety of ways, these companies are assisting customers transition to advanced automation of their machining operations.
Some machine tool upgrades are coming as a result of a strong push from users. For example, electric vehicle manufacturers and others are asking for regular systems with higher spindle speeds and horsepower, according to Tim Thiessen, vice president of sales and marketing at Okuma America Corp., a machine tool builder in Charlotte, N.C. “There are applications that get into (very high) speed machining—35,000 rpm plus—but I’m not talking about that,” he said. “I’m saying that what has been the sweet spot within the norm of higher speed machining is moving up.”
While Okuma might typically offer 75-hp machines with spindle speeds up to 10,000 rpm, many customers are now requesting 18,000 rpm spindles at 100 or 150 hp, he noted. “It would be one thing if we’re considering that a niche application, but I’m seeing that become more and more mainstream within the industry.”
According to Thiessen, Okuma customers want more machine horsepower so they can accelerate to high spindle speeds in a matter of seconds. And they want higher spindle speeds to boost feed rates and reduce cycle times, usually when machining aluminum or titanium, he added.
In addition to making machines more capable, suppliers are trying to make them easier to use. One way is by incorporating conversational control, a text-based technology that lets users input programming information in response to items on simple menus that appear on control screens.
For example, DMG Mori USA Inc. in Hoffman Estates, Illinois, offers what it calls technology cycles, a conversational-control option designed to simplify advanced programming for operations such as gear skiving. Instead of creating the necessary program offline, technology cycles “allow complex programming cycles to be input at the machine tool,” said Gerald Owen, DMG’s general manager of national engineering. They also let operators make adjustments to programs on the fly, he added.
DMG is one of a number of machine makers offering such features. “Combining and simplifying what previously were very high-end functions and (providing) a simpler, easier interface to those is a trend across the industry,” Owen said.
Other advanced machine tool features take advantage of developments in the much-discussed field of artificial intelligence. For example, Smooth Ai Thermal Shield from Mazak Corp., Florence, Ky., is included with all of Mazak’s newer machines to compensate for thermal distortion of machine components due to temperature fluctuations caused by machine operation or the environment. In the automatic version, sensors continuously gather temperature data, which is stored and analyzed by software that learns from the data so it can make adjustments in process parameters when necessary to prevent temperature-related changes in the machine from affecting part quality.
“The idea is to keep the machine stable throughout the day or machining process,” said Jared Leick, Mazak’s machining center product group manager. “And the goal is to make sure that you’re getting all good parts off the machine.”
A.I. also plays a key role in the operation of Mazak’s spindle health-monitoring feature. The purpose of this feature is “to prevent a spindle from seizing up or failing while you’re cutting,” Leick said. “You don’t want to be cutting a $10,000 part and (have) a spindle seize up or stop on you so you have to scrap the part.”
Developed in partnership with the University of Cincinnati Engineering School, spindle health monitoring relies on algorithms that compare the vibration and frequency of operating spindle bearings to charts that show vibration and frequency values obtained by testing real spindles. The development team charted data derived from good spindles, defective spindles, and spindles that were at the point of wearing out.
“The idea is to monitor your spindle in real time and send a (signal) to the operator if there’s some issue in order to prevent your spindle from failing while it’s machining,” Leick said.
Another major development in the machine tool industry is the emergence of super-versatile alternatives to dedicated machines for individual operations, which could be called all-in-one machine tools. An example would be a mill-turn machine that can also handle grinding, gear skiving, and advanced metrology.
“That’s the industry trend,” said Owen at DMG, which makes such machines. “Instead of machines that only do one thing, we’re finally seeing the evolution of machine tools into a one-stop, does-it-all platform.”
The advantages of all-in-one machining include improved part accuracy due to fewer setups, as well as the need for fewer different machines on the shop floor. If a single platform can serve as a lathe, a three-axis mill, and a grinder, for example, a shop that requires all three machine technologies doesn’t need a separate machine for each technology that takes up valuable floor space, Owen noted. Instead, the shop can get by with a single multifunction machine—or it can fill the same floor space that would be taken up by three single-technology machines with three multifunction machines to greatly expand its capabilities.
Today’s all-in-one machines can include more than just multiple machining functions. Owen pointed out that they can also offer functions traditionally performed by peripheral systems, such as advanced metrology. “The advancements in the last five years in metrology on machine tools can be a huge advantage to customers,” he said. Instead of purchasing a separate coordinate measuring machine, for instance, “you can basically turn your machine into a CMM. You can use cameras and lasers to measure parts that will give you the same results as a CMM.”
On the other hand, Owen noted that the machining capabilities of an all-in-one unit may not match those of a machine designed for a specific operation.
“I would say that a traditional grinding machine is always going to be a little more accurate than a machine tool,” he said. So there’s probably a point where a dedicated grinding machine would have to be employed, he acknowledged, adding this could be when micron-level accuracies are required.
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