Many metalcasting operations are machining operations by default, having added grinding and finishing cells in order to prep cast products for shipment. Others are machine shops by demand, having accepted customers’ delivery requirements. Increasingly, foundries are adopting machining because they see it as a way to distinguish their brand and derive new revenue streams. It may or may not be a natural extension of their skills, but they’re in business to prosper and machining offers that potential.
Whether they are new to machining or not, foundries will find that machining is a new dimension in manufacturing technology, with a portfolio of techniques, topics and trends. The talking points cover not just CNC machine centers, but tooling, automation and controls, software, logistics, material science, and various other issues that need to be understood. Let’s get started:
“There is an increased support for green engineering,” observed Tim Shinbara, director of manufacturing technology for AMT, a trade association for machine tool builders, distributors, and their customers. “From the controls perspective, they’re installing intelligence that allows you to really manage the energy you’re using. It’s all happening simultaneously, all behind the curtain on the controls.”
Rajas Sukthankar, business manager of machine tool segment at Siemens Motion Control, is tracking this phenomenon, too. “Energy efficiency is figuring more and more in the activities on the manufacturing floor,” he said. “Everybody is after consuming less energy and producing parts with less energy.” Successfully doing so provides manufacturers with a real competitive advantage because it reduces their overall manufacturing and energy costs and, more significantly, the overall cost of production per part.
Lately, Siemens CNC controls have been promoted for their ability to help machinists tap potential energy savings, to control costs. “There are certain key combinations that are defined in the new software generation of CNC that really help us conserve energy directly on the machine, behind the scenes,” he said.
One particular emphasis by Siemens is an innovative energy feedback or energy regeneration system incorporated into drives for larger machines. These CNC drives feed energy back into the line in a large part like a spindle.
“In the past, all of this energy was burned, generating heat either outside or inside the panel. No more,” he said. “We directly feed back all of this energy to the lines, making the machines more energy efficient.”
Within machining operations, MAG’s cryogenic technology has made an impact by controlling heat generated in the machining of the increasingly important hard alloys (e.g., titanium) and composites, while also addressing various green objectives. Functionally, it eliminates the coolant mechanisms running though traditional CNC machines.
MAG’s Mike Judge explained that most machining operations still flood the cutting zone with water-soluble coolants, creating a “nightmare” in terms of maintainability, reliability and sustainability. “Very simply, what cryogenics does is allow us to eliminate all water-soluble coolants,” Judge said . “It allows us to eliminate the energy consumption that comes with moving chips and filtration systems, and it allows us to eliminate the costs associated with raw materials for replenishment of water-soluble coolants.”
The technology represents the next phase of the development of an alternative system called MQL, or Minimum Quantity Lubrication, which uses an oil-mixed lubricating process as opposed to water-soluble coolants.
“All around the initiative of becoming more green, MAG has more MQL machines in the field than anybody else in the world,” Judge claimed. The next evolution of MQL is cryogenics, he said.
“Liquid nitrogen totally eliminates the coolant system and the energy to run it,” Judge explained . It also cuts coolant disposal costs and potentially eliminates the need for in-process part washing after exposure to water-soluble or oil-based coolants during machining.”
As a bonus, the system also radically reduces the cost and labor involved with chip reclamation and recycling.
“A lot of investment is made by our customers to reclaim and recycle their chips, and there are a lot of standards that are placed on them for a percentage of clean chips before it can be recycled and reclaimed,” he explained .
With cryogenic technology, the chips can move directly from the machine to reclamation and recycling without any end-process washing.
IT in production
It was not so long ago that IT and manufacturing operations were distinct organizational functions. Just five to 10 years ago, AMT president Douglas Woods noted, there was little need, or opportunity, for the two to come together. “Now,” he said, “not only are they coming together, but they’re starting to be woven seamlessly, and the tapestry that is coming out of it is going to start being the major differentiator in U.S. manufacturing.”
This trend is visible in the design of new machine tools, which include hi-res visualization monitors, data displays and endless hardware and software offerings. What’s inside is even more important, as proven by Mazak’s increasing number of machines incorporating the MTConnect protocol, allowing them to capture, communicate and report vital production data that would be lost in traditional machines.
MTConnect is the communication standard for equipment interoperability across all types of devices and equipment used in machining and manufacturing technology. The potential for this marriage of IT and machine tools is evident in systems like Mazak’s Hyper Quadrex 250MSY multitasking turning center, which features a bar feeder that communicates as a united system using MTConnect’s open communication protocol.
“The whole machine and the bar feeder work together as an integral system,” according to Brian Papke, Mazak president. “The whole package, the whole system is capable of being monitored for its utilization and productivity.”
The MTConnect standard is gaining momentum among machine shops and manufacturers, regardless of the markets they supply. “It really doesn’t know any boundaries in terms of industries,” Papke said. “Whether you’re in aerospace, defense, energy, automotive, medical, construction equipment or anything else, there is someone in each segment of these industries that has moved into MTConnect.”
The advantage, he continued, is better access to critical performance data that can help increase productivity and lower costs. “When you look at machine tools today, everybody focuses on uptime of machines,” he said. In the current state of the technology, machine availability (i.e., uptime) can be over 98%, but that number doesn’t tell the whole story.
“You’ve also got to consider how much time is actually available for chip cutting and how much is actually used for chip cutting,” Papke said. Among most manufacturers, that time is a much shorter — as much as 20% less!
MTConnect reveals those kinds of insights and can help machining operations keep their spindles turning more efficiently, and with greater yields, said AMT’s Paul Warndorf, v.p. - Manufacturing Technology. “The average is about 20% utilization improvement for companies implementing MTConnect because now they have been able to actually understand what’s going on with the equipment and with their shop floor,” he said.
Such results are pushing MTConnect compliance throughout the machining sector. Over 100 organizations are already in the loop already. “From a builder’s standpoint, some of the largest machine tool developers in the world are making it a feature that is available in their machines,” Warndorf said. “There is a lot of new equipment coming out with it built-in.”
Putting technology to work
Having multiple technology developers and machine builders coordinating all this progress is shown in practical ways on hundreds of shop floors. Webb Wheel Products, Inc. has a 100,000-sq. ft. plant in Tell City, IN, where it machines ductile and gray iron castings into brake drums and hubs for the heavy-duty trailer market. The core of operation is a series of 16 Maus machining centers for turning, drilling, grinding and marking products. Maus vertical lathes are built as single-station, dedicated operations, intermediate work cells, and turnkey production lines, and the builder uses Siemens controls on all the machines it builds.
David Link, v.p. - manufacturing, said the plant design effort emphasized total control of the complete machining process. Importantly, Webb Wheel uses a custom material handling system that also needed to be linked to the machining center control panels, for integrated part movement.
In an impressive demonstration of coordinated design, technology, and controls, the plant manages to produce over 400 varieties of brake drums, with reliability and efficiency.