by Mary Scianna
Energy saving options on turning machines are cost saving advantages for manufacturers
Machining, by its very nature, is an energy-intensive process, so when you’re considering energy reduction strategies as part of a cost-cutting plan for your machine shop, it can be somewhat of an obstacle.
That said, machine tool builders are incorporating more “eco friendly” features into their machines. The move to more energy-efficient machines began many years ago. Indeed, most machine tools today offer power-saving features such as automatic power shut-down or power on and energy efficient LED lighting inside
“As far as making machines ‘greener’, a lot of what is being done comes down to making the machine more efficient,” says David Fischer, lathe product specialist with Okuma, Charlotte, NC.
Making a machine more efficient means making the components in the machine, such as motors and drives, more efficient. Okuma’s PREX motors are one example. Fischer says the motors are 78 to 93 per cent more efficient than the typical VAC motors used on most machines. The efficiency is due, in part, to the reduction in heat generation from the rotor and coil. The motor reduces rotor inertia by 45 per cent and offers shorter acceleration times, approximately 1.5 seconds shorter than the company’s previous motors (0.8 seconds versus 2.3 seconds).
Vince D’Alessio, executive vice president of Elliott Matsuura Canada, Oakville, ON, a distributor that represents several machine tool builders such as Hurco, Matsuura, Nakamura-Tome and GFAgieCharmilles, says most builders are now integrating solutions to reduce power consumption. “The most prominent feature is that controls are monitoring usage and have the ability to power down motors and other high power consumption devices when not in use.”
For instance, D’Alessio says Matsuura machines have the Matsuura Intelligent Meister System (MIMS) software that features a function called Eco Meister equipped with power saving options.
Another example is Mazak’s “Energy Dashboard” which monitors energy consumption and power usage, and calculates energy savings. Launched at IMTS in 2010, the energy dashboard is now available as an option on Mazak’s machines, says Neil Desrosiers, applications engineer/developer at Mazak Corp., Florence, KY.
“So now our machines have energy saving features and people can look at that energy consumption using the Energy Dashboard. But what we started hearing from end users is what is the benefit of monitoring one machine when I have 100 other machines? That’s where MT Connect comes into play. Using MT Connect, customers, on average are seeing a 15 to 20 per cent productivity increase, just by monitoring the machining process using features like the Energy Dashboard and the Maintenance Dashboard, that monitors other things, such as coolant levels.”
Mazak has been a big proponent of MTConnect, a set of open architecture, royalty-free standards launched by the Association for Manufacturing Technology (AMT) in 2007. MT Connect software links shop floor technologies via controls, devices and software, allowing the sharing of data (via networks using the Internet) between different equipment in a manufacturing facility.
Desrosiers says more than 200 Mazak machines are now MTConnect-compliant.
Another example comes from DMG. All of the company’s machines are equipped with an Adaptive Control Monitor (ACM) from Omative Systems, a software program that monitors cutting tool conditions in real time, automatically adjusts feed rates to optimal levels and indicates when to change worn tools. The software helps to reduce cycle times and minimize production disruptions.
“The software monitors in real time the power and load of the spindle, in addition to cutting parameters,” explains Roberto Colombo, applications manager, DMG Canada, Mississauga, ON. “Adjusting the speeds and feeds in real time is a good advantage because it allows you optimize the machining process and at the end of the day this saves energy.”
Builders are also making machines that run at faster speeds and feeds to make parts more quickly. That in itself is a “green” feature, says Okuma’s David Fischer, but to achieve some of the very high speeds and feeds requires the use of linear motor technology.
“Everyone wants to go faster and when you go faster, you need to use more energy,” says Mazak Corp. Canada’s Ray Buxton, based in Cambridge, ON. “Linear motors are fast, but they generate heat and you need chillers to cool things down. It’s also a technology that is prone to contamination and we find the servo motors are better when it comes to efficiencies and faster speeds.”
Making machines “greener” means making them more energy efficient, but it means cutting machining costs too. For instance, Mazak implemented two changes to its machines. One is to reduce the floor space requirement of its machines in Canada by designing machines with an internal transformer offering 575 volts. Buxton says these internal transformers can save manufacturers approximately 5 per cent of electricity usage over the life of the machine “and that is significant,” says Buxton.
A second change, one that many builders are now implementing, is replacing lubrication oils in the ways with grease. “Oil leaks out and runs into the coolant. It can cause bacterial growth in the coolant, which then must be disposed. By using grease, you improve coolant life and the customer reduces the problems and costs associated with coolant disposal,” adds Buxton. SMT