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:

Green shoots

“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.