Advances in CNC machine tool controls
- Published: July 30, 2016
Smart CNCs bring efficiency, predictability, and greater control to shops of all sizes
My dishwasher knows whether I rinsed the pots and pans last night. My refrigerator tells me when the eggs are expired. My thermostat knows if I’m away, and is pretty good at predicting when I’ll come home. My smart phone lets me talk to all of them, and issue commands from far away. Smart, interconnected devices are everywhere, making autonomous decisions, gathering information and sharing it with others, and generally improving the lives of their human masters.
The shop floor is no exception. Manufacturing companies have long expected CNC equipment to gain speed, accuracy, and power with each passing year, but as machine tool builders continue to embrace Industry 4.0 and the Industrial Internet of Things (IIoT), their metal cutting wares will become smarter as well.
Early warning systems
One example of this is DMG MORI’s Celos control which, according to the company, has an open architecture that provides for information exchange and integration with other systems within the manufacturing organization. The result is up to 30 per cent time saving in tooling times and 50 per cent lower time and effort for the calculation of technology values or the search for important information, claims DMG MORI.
Together with industrial product supplier Schaeffler Technologies, DMG MORI has embarked on a joint project entitled Machine Tool 4.0 by placing more than 60 sensors in various components of a DMC 80 FD duoBlockmill-turn centre. Vibration, temperature, and cutting forces are continuously monitored and analyzed, allowing real-time machine status and performance assessments, and providing an early warning system of potential machine downtime.
Mazak Corp. is another machine builder with an eye toward smart solutions. Its Mazatrol SmoothX CNC control is said to reduce gouging and control vibration during corner machining by automatically adjusting toolpaths based on preset values. Intelligent pocketing routines maintain consistent cutter engagement angles, offering up to 35 per cent faster machining of tough materials. And Quick EIA onboard simulation capability allows operators to quickly check for errors in part programs and avoid potential collisions.
Like DMG MORI and other industry leaders, Mazak is reaching beyond corporate walls, joining forces with IT hardware and software companies to bring new breeds of CNC controls online while still keeping them secure. For instance, through a partnership with networking equipment provider Cisco and machine monitoring and connectivity developer Memex, Mazak’s Smart Box security platform protects Internet-capable CNCs from unauthorized access while collecting machine data and other forms of information for further analysis, and does so for all brands of smart controls.
There’s an app for that
Brad Klippstein, controls product specialist at Okuma America Corp., Charlotte, NC, says there’s enough information coming from most machine tools to fill a firehose. The challenge is harnessing that data and making sense of it all. “How long the machine has been on, whether any alarms have occurred, feed and speed information, which jobs are running—customers have a lot of options for what data they want, how often to pull it, and what they’re going to do with it to increase productivity.”
Those with an Okuma machine tool can find a number of free downloadable tools to leverage this data on the company’s AppStore. These include software for gauge and tool presetter integration, barcode scanning apps, coolant and cycle status monitoring, and apps for scheduling maintenance or sending alarm texts or emails to your smartphone.
Okuma even invites qualified software developers to submit their work for inclusion in the AppStore. And those customers with a knack for coding will find additional opportunities through Okuma’s OSP suite of development tools. “I visited a customer in Texas a few months ago who wrote his own app for remote management of tool offsets,” Klippstein says. “The guy had no programming experience at all, but he was able to figure it out on his own. It’s pretty cool the things you can do now.”
Klippstein says the depth of Okuma’s control technology goes well beyond a few dozen software apps, however. The company’s OSP-P control is an open architecture PC-based platform with a Microsoft Windows operating system, and offers a number of control features designed to improve machining operations and simplify life on the shop floor. These include Super-NURBS for 3D surfacing and its 2D cousin, Hi-Cut Pro. “Super-NURBS judges the machining shapes from G01 feed commands and reconstructs the original shapes using free-form curves, while Hi-Cut Pro allows the user to set accuracy tolerances on the rectilinear axes. Both control axis acceleration and deceleration in high feed scenarios. There’s also I-MAP, a graphical programming interface that’s “a step up from G-code programming, but not quite conversational,” he says.
The proliferation of PC-based controls together with builder-sponsored software development kits, or SDKs, is one of the driving factors behind hardware and software integration throughout the industry. Add to that an easy way to communicate with the machine tool and there’s little in the way of linking the shop floor to the company’s ERP system, document stores, CAD/CAM and other engineering tools, and providing operators with email, messaging, and web browsing capabilities.
Heindehain Corp., Schaumburg, IL, is one of several control builders offering such a platform with its RemoTools SDK, which TNC product specialist Julian Renz says is designed to communicate directly with Windows applications and can be used in conjunction with C++, VB.NET, C#, and other programming languages to develop a wide variety of software applications. “RemoTools allows you to access control tables, create, delete, or modify information, trigger events, perform file operations, and interact with 3rd party software. There’s also a remote desktop manager available that resides on the Heidenhain TNC control, and supports display and operations of multiple Windows PCs from the machine tool.”
For those who care nothing about software development and just want to make parts, Renz says the TNC control has a DXF converter function and can generate part programs in a semi-automated method via its conversational interface. “Many shops prefer to create programs at the machine tool,” he says. “The TNC offers advanced graphics, is quite easy to learn, and has a variety of standard cycles where you only have to enter a few parameters and the control will execute the cycle.”
The four pillars
“Shops quickly become overwhelmed by the tremendous functionality of machine tools today,” says Vince D’Alessio, vice president of Elliott Matsuura Canada, Oakville, ON. “You have machines with up to twelve axes simultaneous, multiple spindles, possibly hundreds of tools, and new capabilities coming online all the time. It’s intimidating. That’s why machine and control builders are working hard to make the technology easier to understand.”
D’Alessio says there are four key technology “pillars” where machine tool manufacturers are focusing their efforts:
- Predictive maintenance functions that not only monitor machine
health but simplify troubleshooting and recovery steps.
- Energy efficient “ECO” modes that reduce power to motors and pumps during idle times.
- Feature rich controls with onboard CAM systems, designed to greatly simplify machine programming
- Integrated toolpath simulation with advanced graphics and collision avoidance capabilities.
Much of this is made possible through the human machine interface, or HMI. By writing a software layer that sits on the front end of an otherwise all-purpose CNC, builders can tailor their products to specific customer needs and machine tool requirements. D’Alessio points to Matsuura’s G-Tech 31i controller as a good example of this, and Nakamura-Tome’s NT-IPS, both of which have a custom-built “smart” HMI wedded to a Fanuc back end. The result is a CNC that is dependable, affordable, and relatively simple to operate.
“There are several factors driving all of this, but the primary one is simplicity,” he said. “With manufacturing becoming more complex and the average skill level of operators going in the opposite direction, it’s important to make machine tools as intuitive and easy to understand as possible. And because these controls are PC-based, they’re very simple to upgrade whenever new software features come along. All in all, there are a lot of very nice things going on in the industry today.” SMT