Metal Cutting: Multitasking Equipment
Done-in-one setup and machining are all the rage
Multitasking machines are taking on many forms today, contributing to their continuing growth as a prime way in which manufacturers can not only retain their competitive edge, but leap ahead of global competition.
Multifunction machining, combining many processes into one machine or machining cell, is not a new idea. What is new are the strides that are being made as multitasking machines proliferate in producing a wide range of parts from the tiniest connectors and medical devices to large components carved from solid steel.
Visitors to IMTS 2006 will see the latest developments in multitasking machines in action. They will be demonstrating their ability to produce one-off, complex workpieces, or be changed over to produce small lots of parts and workpieces that may or may not be from the same family of parts. Some trends to watch for include:
- Subspindles and milling heads approaching or equaling the power of main turning spindles.
- Demonstrations of how multitasking equipment fits into lean manufacturing strategies.
- Expansion of multitasking beyond the traditional mill/turn combination with more grinding-spindle combinations.
- Sophisticated controls and software for collision avoidance, scheduling, and production analysis.
- Continued blurring of the identity of the multitasking process and machines as either turning or machining centers.
Manufacturers are being challenged to change their production strategies by machines that literally replace a number of machine tools to produce a finished part, and do it with unmatched precision and accuracy.
The reasons can be found in the concept of finishing the part complete in one clamping, reducing setup, and improving quality by reducing the handling necessary to move parts for subsequent processing on other machines.
It is a little bit of a stretch to call rotary transfer machining technology true multitasking, but it, like other equipment designed for high production, does involve multifunction processing of parts that are held in a single chucking. Rotary transfer machines can drill, bore, turn, thread, tap, and broach parts to 1 3/4" (44.4-mm) diam from bar, coil, and blanks in one chucking. The addition of CNC technology is giving rotary transfer machines the ability to change over quickly for smaller lot sizes of complex parts.
Hydromat Inc. (St. Louis) will exhibit its EPIC R/T CNC rotary transfer machine alongside a legacy conventional Hydromat machine. The EPIC features embedded CNC controls at each spindle station, enabling the user to change over quickly reconfiguring the machine without making wiring or other time-consuming physical changes to setup.
While machine tool builders may search for the right terminology to describe their own versions of multitasking equipment, machines typically perform more than one metal removal process, simultaneously from one part with more than one cutting tool or from a number of parts simultaneously, or sequentially. Multitasking machines began as simple mill-turns that were created by adding live tooling for milling to CNC lathes.
At IMTS 2006, visitors will have a chance to see just how the concept has evolved from its millturn beginning.
Machines that readily conform to the definition of true multitasking machines include everything from Swiss turns to mill-turns, CNC lathes with live tools and multiple spindles for turning, grinding, and/or milling. Multitasking CNC lathes feature a Y axis that allows turrets to move from side to side and have full milling or drilling capability off the spindle centerline. A B axis allows rotation around the Y axis for drilling at an angle or contour milling.
Mazak Corp. (Florence, KY), a pioneer in development of done-in-one multitasking machining, will introduce a number of product improvements across its broad line of multitasking machine tools. Mazak's Integrex IV series machines will feature a new lower turret that can offer processing flexibility and provide more machining functions, or act as a tailstock or steady rest for some parts.
Integrex IV series machines show the versatility of the multitasking concept, and can be used to produce workpieces that normally would require turning centers, vertical machining centers, and horizontal machining centers. For example, by utilizing both upper and lower turrets and synchronized control of the B axis and C axis, complex parts like roller gear cams can be produced more productively.
Featured on all models in the Mazak booth will be its Mazatrol Matrix CNC control that can run maximum feedrates for machining complex surfaces that are four times faster than the previous generation. Features of the Matrix CNC include minimum program increments of 0.00001" (0.0001 mm) for both Mazatrol conversational programming and EIA/ISO input, assuring high accuracy machining at high speeds.
Mazak will also exhibit the expanded QTN line of Nexus CNC turning centers that includes two models, the QTN-250MSY and QTN-350MY, both of which feature milling spindles and Y-axis capabilities to incorporate more functions such as face milling or precision drilling in a single setup.
"Manufacturers must take labor out of the process to be competitive in the global market," says William C. Jacobson, president, Romi Machine Tools Ltd. (Erlanger, KY). "There is no question that US manufacturers are being more successful in producing the more complex components, the more complex the component the better the chance that we have to do it."
Romi developed its multitasking E-series turning centers to perform turning, boring, milling, and tapping in one setup in a machine with a compact footprint. "Dropping the part off complete, having a Y axis and being able to mill at a very good rate, is what's important to our job-shop customers," says Jacobson.
The E 320 turning centers that will be exhibited can be configured with one or two spindles with full C-axis, live tools, and a Y-axis for mid and high-volume production. The left spindle features a belt-driven cartridge-style gearless headstock with a high-torque 25-hp or 35-hp (18.6 or 26.1-kW) GE Fanuc AC spindle motor with a variable speed drive. The right spindle features a high-torque 25 hp (18.6 kW) GE Fanuc AC spindle motor with a variable speed drive. The A2-6" (203-mm) spindle features rigid mounting, 2.56" (65-mm) bar capacity and a 4–4500-rpm speed range. The left side can also be equipped with an A2-8 spindle with a 3" (77-mm) bar capacity and a 3–3000-rpm speed range. Axis travels are Z-axis, 23.82" (605 mm), X axis, 8.66" (219.9 mm), and Y axis, 3.94" (100 mm).
Among the machines that Mori Seiki USA Inc. (Rolling Meadows, IL) will exhibit are five models of its NT series of multitasking machines. "There is no tradeoff in our ability to mill or turn with the NT series machines," says Thomas R. Dillon, president. "We feel we have leapfrogged the field with the performance of these machines. Milling and turning processing are comparable to any turning center or machining center."
Mori Seiki's NT series of machines combines the company's DCG (Driven at the Center of Gravity) technology and its box-in-box construction to produce a rigid machine capable of both high accel/decel to minimize vibration and produce improved part surface finishes. Typical applications include complex aircraft parts, automotive, energy industry, die and mold, and construction-related industries.
Mori Seiki will also announce the winners of the Innovations of the Americas contest in the booth during IMTS. Supported by SME, the contest is designed to recognize the finest innovations and technical expertise in the Americas. "As a company, we are known as innovators," Dillon says. "As a result, we're thrilled to acknowledge and reward innovative machinists that employ remarkable technologies on a daily basis to solve manufacturing and engineering challenges."
The contest is open to any company, school, or research institution located in North, Central, or South America that is involved in metalcutting and is experienced with CNC machine tools. Contest entries must be received by August 25, 2006. For more information, please visit moriseikius.com.
Index Corp. (Noblesville, IN) will introduce its Grinding Machine Center to the North American market at IMTS. It is capable of ID and OD grinding after turning. "The Grinding Machine Center is already a success in Germany where 60 machines have been sold in less than a year," says Olaf Tessarzyk, Index president and CEO.
Grinding is performed with an 80,000-rpm spindle after turning and the machine includes dressing and air gaging. "The Grinding Machine Center has found applications in the automotive industry for precision production of such parts as hydraulics, fuel injectors, and for grinding the ID of hydraulic pistons or cages, he says.
Methods Machine Tools Inc. (Sudbury, MA) will exhibit the Nakamura-Tome Super NTY3 multitasking turning center that is designed to eliminate lost productivity resulting from tool changes. Secret to the machine's performance are three turrets, each with a Y axis, that allow it to outperform single-tool multitasking machines by allowing one-pass complete turning/machining/finishing in reduced part-cycle times.
The Super NTY3 does it by offering multipoint machining with process integration, combining turning and milling capabilities in one machine. Its three 6000-rpm milling motors can simultaneously machine two flat surfaces (top and bottom) on one spindle, and one surface on the other. Each turret holds 12 driven or 24 stationary tools, for a maximum of 72 tool stations. The Super NTY2 has a maximum turning diam of 6.89" (175 mm), a maximum turning length of 23.5" (588 mm), and a bar capacity of 1.65" (42 mm).
The equipment below is a sample of the multitasking technology that will be on display at IMTS 2006. — James Lorincz
Large Part Machining
Nexus QTN 450M multitasking CNC turning centers feature a large-bore spindle for machining large-diam parts. Maximum swing is 33.3" (845.8 mm) and maximum machining diam is 22.8" (579 mm). Turning spindle is 40 hp (29.8 kW) with 1327 lb-ft (1799 Nm) of torque and a 12-station turret with a 10-hp (7.4-kW), 4000-rpm milling spindle. Maximum speed on the integrated spindle/motor unit is 2000 rpm and the spindle bore is 6.5" (165 mm). Feed rates are 1181 ipm (30 m/min) in X and Z axes.
Ph: (859) 342-1700
CNC Multitasking Center
Model N 40 MC CNC center is capable of turning, milling, and drilling. Feed rates to 30 m/min and torques to 12,800 Nm on turning spindle and to 678 Nm on milling spindle can be achieved. Maximum power of the turning spindle is 124 kW and on the milling spindle is 45.3 kW. Spindle drives have integral C-axis functionality and a spindle coupling to generate geometrical shapes. ATC capacity is 48 with optional tool pockets for 96 or 144 tools.
Niles-Simmons Industrieanlagen GmbH
Ph: 49-371-802-0 (Germany)
Mill Turn Centers
NT Series of integrated mill-turn centers fully combine a lathe and a machining center. NT Series machines contain a B axis that uses a direct-drive motor, eliminating backlash and making high-speed rotation possible. Maximum spindle speed is 5000 rpm with a maximum toolspindle speed of 12,000 rpm. ATC features a tool-to-tool time of 1 sec and a chip-tochip time of 3.4 sec. NT Series machines have a total of 66 variations based on spindle, lower turret, and center-support options.
Mori Seiki USA Inc.
Ph: (847) 593-5400
Multitasking B-Axis Unit
Model ES-B multitasking machine with B axis integrates many fixed and rotating tool processes on the machine. Included are internal and external turning, facing, cutting-off, offset, and angled milling, drilling, and tapping, and profiling with interpolation. The motor spindle enables rotation at high speed for milling and rigid clamping of the tool for turning. Spindle speed for the model ES-B is 12,000 rpm at 30-40 kW.
Duplomatic Automazione S.P.A.
Ph: 39-0331-472-216 (Italy)
Three-Turret Turning Center
Nakamura-Tome Super NTY3 turning center has three turrets, each with a Y axis, for one-pass complete turning, machining, and finishing. The Super NTY3 offers multipoint machining with process integration. Three 6000-rpm milling motors can simultaneously machine two flat surfaces (top and bottom) on one spindle and one surface on the other. Each turret has 12 driven or 24 stationary tools for a maximum of 72 tool stations. Accelerating Y axes have travels of 2.44" (62 mm).
Methods Machine Tools Inc.
Ph: (978) 443-5388
Single Setup Machining
Puma MX series mill-turns produce parts in a single setup. Processing ranges from simple turning or milling to complex, simultaneous, multiaxis machining. The dual-spindle multitasking Puma MX features a 12-station turning tool turret. Live or static tools can be mounted at any station and oriented toward either the main or subspindle. Live tools are 7.5-hp (5.6-kW) motor driven with a maximum of 4000 rpm. Turning spindle motors can be 25 or 35 hp (18.6 or 26 kW) depending on model chosen.
Doosan Daewoo Infracore
Ph: (973) 618-2500
E-Series turning centers are designed to deliver consistent accuracy from first to last part in mid and high-volume production. The E320 with Y axis offers turning, boring, milling, and tapping in one setup. The E320 can be configured with one or two spindles with full C axis, live tools, and a Y axis. Main components are assembled on a solid base incorporating the FEA-designed polygon-shaped rib structure around a torque-tube core for minimal heat distortion and maximum vibration dampening.
Romi Machine Tools Ltd.
Ph: (859) 647-7566
Millturn Model M40 has 20 x 108" (508 x 2743-mm) machining capacity with Y-axis and B-axis capability. Turning spindle is 50 hp (37 kW) with a 20-hp (14.9 kW) B-axis milling spindle. Tools to 40" (1016 mm) can be handled. Millturn Model M120 has 48 x 120" (1219 x 3048-mm) machining capacity with Y-axis and B-axis capability. Turning spindle is 120 hp (89 kW) and B-axis milling spindle is 74 hp (55 kW). The M120 will demonstrate five-axis machining, gear hobbing, gundrilling, deep-hole boring, and B-axis turning with long boring bars. Tool magazine holds 108 tools to 61" (1549-mm) long.
WFL Millturn Technologies Inc.
Ph: (636) 485-8393
Y-Axis Multitasking Center
Independent axis design of the TB-25-YMBC allows its X, Y and Z-axes to move independently. X, Y and Z axes are 90° to each other and do not require movement of two axes to enable Y-axis motion. Using conventional programming, the machine can run as a turning center and a four-axis machining center. Single-spindle version has a 10" (254-mm) chuck with swing of 21" (533-mm), turning length of 24" (610 mm), bar capacity of 2.5" (63.5 mm), and full-travel tailstock. The twin-spindle version has a second spindle with an 8" (203-mm) chuck, and spindle speed of 5000 rpm.
Tong Tai Seiki USA Inc.
Ph: (845) 267-5500
This article was first published in the August 2006 edition of Manufacturing Engineering magazine.