Derek Korn joined Modern Machine Shop in 2004, but has been writing about manufacturing since 1997. His mechanical engineering degree from the University of Cincinnati’s College of Applied Science provides a solid foundation for understanding and explaining how innovative shops apply advanced machining technologies. As you might gather from this photo, he’s the car guy of the MMS bunch. But his ’55 Chevy isn’t as nice as the hotrod he’s standing next to. In fact, his car needs a right-front fender spear if you know anybody willing to part with one.
I recently attended the opening day of DMG/Mori Seiki USA’s ninth Innovation Days event at the company’s U.S. headquarters in Hoffman Estates, Illinois. This year’s event featured 45 machines—five of which were being introduced to the U.S. market—located in industry-specific areas seen by more than 3,200 attendees from 10 countries. Attendance was up 45 percent compared to last year’s event.
The new machines being introduced to the U.S. market included the five-axis DMC 85 monoblock and Vertical Mate 125 multi-process grinding machine shown below as well as the NVX7000/50 with large X-axis travel and NLX1500SY/500 and NLX2000SY/700 turning centers featuring the company’s Built In Motor Turret (BMT).
This DMC 85 monoblock at the event featured an automatic pallet changer that takes up less than 43 sq. ft. of floor space. The company’s Vertical Mate 125 is said to offer a simple, sturdy structure and affordable price enabling users to perform ID/OD and face grinding in one setup.
The event also highlighted the InvoMilling process developed in conjunction with Sandvik. An alternative to grinding, InvoMilling is a machining technique that enables fast, efficient production of spur and helical gears in multitasking machines and machining centers. The event also featured the “disruptive technology” demonstration shown below whereby in-process shaft hardening was performed on an NT4200 DCG turn-mill. The machine used a special high-rpm grinding process to generate the level of friction needed for localized heat treatment of specific part features.
One of the many event presentations highlighted the company’s C-frame MillTap 700, which the company says is a more robust alternative to conventional cross-table drill/tap machines. The MillTap 700 is said to offer more powerful milling capabilities and a larger table in a smaller overall footprint. Each day’s presentations focused on a specific industry—specifically, automotive, aerospace and gear production—while the fourth day welcomed 200 students for special programs and tours.
This demonstration showed how automation could be added to the MillTap 700 with dust evacuation for machining components made of graphite and other similar materials.
The National Institute for Metalworking Skills (NIMS) was also on hand to present DMG/Mori Seiki University (DMSU) with its official accreditation for its CNC machining and maintenance training programs. The company says it is the only machine tool builder to receive this NIMS accreditation. Through a balance of on-site, web-based and classroom training formats, DMSU has established itself as a leading resource helping to transform entry-level machinists into the highly skilled experts that the industry demands. “We at DMG/ Mori Seiki USA not only pride ourselves on our machine tool technology, but also that we help our customers make the most of it through solid support and education,” says Rod Jones, DMSU’s chief learning officer who led the accreditation process. “We’re delighted to have received the NIMS accreditation because it proves our dedication to going beyond being a machine-tool builder to a respected industry educator.”
Josh Senour, CNC operator at BCI, is using one of the clinic’s two computer stations to complete his online health risk assessment. Employees can also review health-education books and DVDs in a nearby room.
Challenges sometimes spur atypical solutions. Bremen Castings Inc. (BCI) is a case in point. BCI has leveraged new foundry and machining technology to become a highly competitive supplier of machined ductile and gray iron castings to a myriad of customers. It is well-served by its willingness to try new manufacturing and management approaches. This business ethos has recently led BCI to adopt an interesting strategy to manage rising health care costs that’s rare for a company with under 300 employees: It established an on-site health care clinic to provide insured employees and their dependents free primary care, generic prescription drugs and, perhaps most importantly, personal health coaching to improve their overall wellness. Learn more.
On April 30, I attended an event Makino hosted its U.S. headquarters in Mason, Ohio that highlighted solutions for effective production of aerospace structural components. The event featured a number of machining demonstrations for both aluminum and titanium components.
For example, the company’s T2 and T4 machines are well-suited for big titanium components. The T2 offers six-axis positioning and 5-axis contouring capabilities to reduce the number of setups and refixturing time which helps ensure feature-to-feature accuracy. The larger T4 is effective machining parts with thin walls and floors, deep pockets, and hard-to-reach corners with its ±110 degrees of A-axis travel and rigid construction.
Visitors were also able to see a number of five-axis machining demonstrations for aluminum structural components, including Makino’s MAG and DP series machines. The company also highlighted what it calls “right size” machines for smaller aerospace structural components. One example is the a61nx-5E, which is a 24,000-rpm five-axis horizontal machine built on a 500-mm HMC platform. At the event, it was machining an aluminum landing edge segment, demonstrating one-shot wall finishing, high speed floor finishing and material removal rates as high as 300 cubic IPM. The machine features an atypical pallet changing system for its twin, direct-drive rotary tables that brings effective ergonomics to five-axis machining. This video shows a pallet change whereby a vertically fixtured pallet is removed from the workzone, rotated 180-degrees and presented horizontally to an operator. At the same time, the pallet on the opposite rotary table is loaded into the machine.
The event also featured a presentation by representatives of Exacta Aerospace, which has recently integrated Makino’s MPMax shopfloor data visualization and management software. In 2012, the shop began a process of accounting for all available spindle time and categorizing downtime for analysis. It purchased MPMax to aid in data collection and reporting of spindle utilization. For example, a shop monitor (like the one shown below) reports real-time status of machines with numerous live data points. In addition, status charts offer a quick snapshot of how machines are being utilized so managers can get a good visual about utilization gaps over periods of time.
Exacta’s mantra is “if you can’t measure it, you can’t manage it.” It feels its approach to tracking spindle utilization will help with costing and planning because utilization levels are no longer assumed. Plus, live, auto-updating reports will provide increased visibility and accountability while keeping the focus on continuous improvement.
Establishing a more effective overall process reduce drilling time of a 0.31-inch-diameter, 7.8-inch-deep hole in tempered steel from 3 minutes to 10 seconds.
Blaser Swisslube uses its recently expanded 3,200 square-foot technology center in Switzerland to develop and test its metalworking fluids through challenging machining operations similar to those performed by its customers. The four-year-old technology center features a turn-mill, two five-axis machining centers and a five-axis tool-grinding machine. The company collaborates with customers, universities and trade associations on various machining projects to develop optimized processes through careful consideration of elements including machining parameters, tooling and fluid and fluid delivery.
A recent project conducted with the Technische Hochschule technical university in Aachen is a good example of the type of work that’s performed there. The goal was to reduce the machining time required to drill a deep hole in tempered steel with a diameter of 0.31 inch and depth of 7.8 inches. This operation had previously taken three minutes using conventional cutting oil.
The 42CrMo4 + QT steel (having a tensile strength of 1,000 MPa/145 psi) was machined on the company’s Mazak Variaxis 500. First, a Kennametal tool was used to drill pilot holes measuring 8-mm in diameter to a depth of 16 mm. This was followed by a 10-second non-pecking drilling operation using a Titex tool to the final depth of 7.8 inches. Cutting speed and feed for this operation were 394 feet per minute and 0.001 inch per revolution, respectively.
A water-miscible cutting and grinding fluid was pumped through the long drill at 870 psi for effective chip evacuation. It was important that the fluid was able to resist foaming at high pressure and prevent air bubbles from rising in the emulsion. This is because bubbles counteract the cooling action and reduce the flow rate, making it harder to effectively evacuate the chips. Ultimately, this more effective process reduced drilling time per hole from 3 minutes to 10 seconds. (Video of this operation can be found here.)
This is just one of many such projects performed at the company’s technology center. Company CEO Marc Blaser says tests like this demonstrate that productivity, economic efficiency and machining quality depend in large part on the quality of metalworking fluid as well as the expertise of machining specialists.
In this column, I asked to see interesting fixturing solutions that shops have developed to address common (or unique) workholding woes. I’ve received a few replies and will soon report on them. However, this calls to mind a nifty fifth-axis workholding solution for tombstones that KMECNC developed to speed machining while holding tight tolerances for billet RC helicopter engine components. It now offers its five-axis tombstone solution to other shops.