It’s a concept design engineers know well: the ideal product is one with enough features to entice consumers without pushing the price point too high. Just look at the success of the Toyota Camry and Honda Accord.
But it’s not only products that benefit from adhering to the Goldilocks principle; selecting manufacturing equipment that’s “just right” means getting enough production capability to meet your needs while avoiding overspending.
When it comes to machine tools, highly customized solutions can meet a company’s exact specifications but also represent a significant investment. At the other extreme, commodity-type machines come with a lower price tag, at the cost of certain capabilities or overall flexibility.
In this context, modular machine tools can strike a compromise by offering a middle ground between expensive, highly customized solutions and low-cost, off-the-shelf equipment. This relatively recent shift in the machine tool industry goes back to the early days of manufacturing.
A Brief History of Machine Tools
“During the industrial revolution, machine tools were largely one-off solutions customized for customer needs,” explained Kirk Stewart, director of sales for EMAG. “In the decades leading up to WWII, the U.S. led the machine tool industry, but a lot of things happened to change that. Germany had a strong machine tool industry leading up to the war, but it was decimated. After the war, the Japanese machine tool industry came online with the American-funded reconstruction, economic and political reforms, becoming a significant global player in the industry by the 1960s and a dominate force by the 1970s.”
The next major milestone, according to Stewart, was the emergence of computer numerical controls (CNC), which led to a greater demand for standardized machine tools. “CNC systems are very powerful,” he said “but were also very complicated at the onset. Standardizing the machines made implementing CNC controls much easier. Thus, there was a transition over the decades from customized, one-off machines—both on the supply and demand sides—to the supply side wanting to promote more commodity machines to take full advantage of CNC.”
Of course, customized solutions were never fully supplanted by commodity machines, as EMAG well knows from its 150-year history. “Starting in the ‘90s, EMAG LLC in the US, largely had successes with customized solutions,” said Stewart. “However, where EMAG has bridged the gap toward the commodity side is the Modular Standard solution. We have a standard design with some modular variants. EMAG has what you might call an à-la-carte option for how to assemble a machine.”
“EMAG isn’t going to redesign anything in this case, but will rather select from a limited design book and assemble this standard machine. That allows EMAG to be far more competitive in our engineering and manufacturing, because we have a fixed number of modular components to add on to the base design, yet it still allows us to cater the final configuration to the customer’s needs.”
Modular Machining Options
There are three lines of modular machine tools available from EMAG. The lathes in the VL series offer inverted vertical turning with integrated automation, while the VT series turning machines are specifically designed for machining shafts in mid to high volume while also focusing on the self-loading principle. Finally, the VM 9 vertical turning center for large components can be used for a variety of applications, with turning, milling and drilling capabilities.
“When EMAG developed this platform, we didn’t want to compromise the integrity of the machine, so our VL and VT machines all have glass scales, cast-granite machine beds and more than sufficiently powered direct-drive motor spindles and closed-loop cooling systems. All of those core characteristics of EMAG machines are shared both on the modular, standard platform, as well as our customized solutions.”
So, what’s on the menu for these “à-la-carte” machine tools?
“A critical decision point is live tooling,” said Stewart. “If you have live tools, then you’re adding the capability to mill, drill, tap and thread your components. For some builders, it’s a different model of machine, but in the case of EMAG, it’s simply a different variant. The machine is also configured in a way that allows you to upgrade to live tools retroactively if you initially purchased the machine without them.”
In addition to enhanced production capabilities, EMAG’s modular machine tools also have options for quality assurance applications. “The integrated measuring probe is a very popular option, and it also offers a unique functionality within the machine,” said Stewart.
“Many other manufacturers probe the tool and establish the form of the tool, so that the final geometry of the machined workpiece should result in predictable dimensions. EMAG takes a different approach: with the modular add-on of this probe, we can effectively measure the workpiece in the machine. My customers are primarily interested in the quality of the outgoing workpiece versus that of the tool geometry!” As with the live tooling option, the measuring probe can also be added retroactively if it isn’t part of the initial machine purchase.
Modular Machining and Automation
Integrated pick-up automation contributes to machine productivity. (Image courtesy of EMAG.)
EMAG’s TrackMotion automation system allows several machines to be interlinked via a rail system that functions as a combination conveyor belt, pick-and-place and flip-over unit. The “Translift” which runs on a rail system is a lifting and rotating carriage with a programmable electric gripper that can cover 150 meters per minute.
“The vast majority of lathes on the market are horizontal—there’s a 4:1 ratio of sales for horizontal versus vertical,” said Stewart. “When you’re loading and unloading a horizontal lathe, the most common way to do so is manually. If you’re working in a job shop with very low volumes, that’s not a problem, but as soon as you get into a production environment, how you load a horizontal lathe becomes a choose-your-own-adventure experiment. Some customers utilize gantries, some utilize robots and some choose poorly and continue to load manually in a high-volume environment.”
This sort of automation is often carried out by third-party integrators, and the solutions they come up with—like robotic cells—can have a considerable footprint, reduce access to adjacent machines and create a housekeeping mess. In contrast, integrating automated loading and unloading into a modular machine can reduce the amount of floorspace taken up by the line.
“The beauty of EMAG’s TrackMotion system is that, just like the machines, it’s a standard solution but modules can be added to cater a solution for the user in a quick and cost-effective way,” said Stewart. “One TrackMotion might be three meters long, whereas the next can be 20 meters long. The individual components are in half-, one-, or two-meter segments, with the cables and belt drive system manufactured to the required lengths.”
“For us, it’s great to have an automation solution that fits with the VL and VT series of machines, which means our customers don’t need to go to a third-party automation supplier,” Stewart added. “Nor do they need to cobble something together on their own. Ultimately, EMAG can link two to six machines very elegantly and price competitively with a standard solution.”
Modular Machining Challenges
There’s no such thing as a perfect solution in manufacturing—there are always trade-offs in terms of capital investment, efficiency and flexibility. Modular machines fill an important niche in the machine tool market, but they aren’t without their drawbacks.
For example, CAD/CAM software tends to be developed with standardized (i.e. commodity) machine tools in mind. This means that modular machines are not necessarily as straightforward to use with CAD/CAM software compared to their commodity counterparts.
“Perhaps the commodity machines do lend themselves to better interfacing with post-process simulators,” said Stewart. “They’re developed a little more easily for the horizontal lathe because of the configuration. Our machines, because they’re inverted spindle machines and self-loading, are not typically used in the job shop type environment.”
That being said, the programming of EMAG’s machine tools is no different from that of horizontal lathes. “At the end of the day, the VL series is made up of simple 2- or 3-axis machines. In the case of VT series, they’re 4- or 5-axis machines. Ultimately, they are being programmed with the same CNC code that commodity-type machines would be utilizing – in EMAG’s case, the very capable Fanuc 32i.”
Is Modular Machining Right for You?
The question of whether purchasing a modular machine tool is a company’s best option depends on where it sits in the supply chain. Echoing the contrast between customized machines and commodity machines, OEMs tend to favor machine tools that are customized to their own technical specifications, while many Tier-2 suppliers, at least in the automotive industry, prefer to go the commodity route.
“At the moment, the OEMs are still willing to pay a higher price and accept a longer delivery time for a customized machine,” Stewart said. “However, I believe that will begin to change because the higher engineering content and longer lead time creates higher costs. Even if the OEMs accept that for today, they need to be competitive for their own internal pricing for the future.”
The Tier-1 suppliers sit somewhere in between, with some following the lead of OEMs while others recognize the need to compete in a global market and opt for solutions that demand lower capital investments.
For manufacturers looking to bridge the gap between high-cost customized machines and low-cost commodity machines, modular machine tools could be just right.
For more information, visit the EMAG website.
EMAG has sponsored this post. All opinions are mine. –Ian Wright