Tech Front: Drill-Tap Machine Offers Powerful Milling
Drilling and tapping machines represent a category of CNCs that have proven especially effective in high-volume production of a wide variety of small to medium-sized workpieces for the automotive, electronics, medical, and consumer products industries. DMG / Mori Seiki introduced its new Milltap 700 vertical milling and drill-tap center with powerful milling capability at the DMG / Mori Seiki open house held at Deckel Maho’s Pfronten, Germany, manufacturing plant in early February.
The Milltap 700 is the first new development from the DMG / Mori Seiki collaboration. Highlights of the compact machine are its fast ATC, Siemens 840D Solutionline control, as well as stable machine construction, optimal chip disposal capability, and energy-savings of 30% compared to similar machines. Production rate for the Milltap 700 is projected as 100 machines per month from Germany by May and 200 machines per month from Japan by year end.
Designed for machining in a work envelope 700 × 420 × 380-mm (X,Y,Z), the Milltap 700 is equipped with a 25-kW, 10,000-rpm spindle with maximum torque of 45 N•m. A 24,000-rpm, 20-kW, 40-N•m spindle option is also available. Rapid traverse is 60 m/min in all axes with 1.6-g acceleration. Maximum table load of 400 kg is able to accommodate workpieces such as cast aluminum motor housings, aluminum adapter plates, mounting plastics for medical applications, and electronics applications, as well as a wide variety of valve blocks, cam housings, plates, couplings, brackets, engine housings, and pump and connector housings.
The Milltap 700 features a new design with a machine bed built for chip free fall with a chip pan. The machine sits in a small footprint with an installation width of 1.65 m.
The high-speed milling and tapping machine offers fast tool change. The mechanically driven high-speed toolchanger with 15 magazine pockets (25 optional) features tool-change time of 1.1 sec and chip-to-chip time of less than 1.5 sec.
DIN / ISO programming is supplied with the Siemens 840D Solutionline CNC with Sinamics S120 compact inverter and 10.4" (264-mm) screen for efficient programming and dynamic contour accuracy. The JobShop and Sinumerik MDynamics options offer a wide range of graphics programming and high-quality 3-D machining processes. Tool and wear monitoring and visualization of tools and tool types are available. Graphic simulation of the machining process in top view and additional views, including automatic calculation and display of the machining time, is possible. ME
For more information on DMG / Mori Seiki USA, go to www.dmgmoriseikiusa.com, or telephone 847-593-5400.
Coolant Jacket Wraps
Around High-Speed Tools
When machining at high speeds, air turbulence frequently prevents coolant from optimally reaching the cutting tool. A shrink chuck with a newly developed Cool Flash System allows the coolant to wrap itself around the tool like a jacket and protect it against such disturbances.
The problem is a familiar one to those who cut at high speeds. The tool causes air turbulences that result from the extremely high speeds, preventing the coolant from reaching the tool as desired. Instead of reaching the cutting tool and cooling it, a greater proportion fans out before reaching the tool.
Leading global provider of toolholding solutions, Haimer GmbH (Igenhausen, Germany) has developed a solution that guarantees an optimum flow of the coolant. The Cool Flash System is being offered as an option for Haimer shrink chucks, which are designed for high-speed machining.
With the Cool Flash-System, bores are introduced in the clamping chuck where the coolant is transported to the face area of the toolholder. Rather than having the coolant exit as a spray pattern toward the tool’s cutting edge, a disk is positioned at the face side of the Cool Flash chuck, which releases a narrow circumferential gap in the direction of the tool. The coolant accumulates at this point on the Cool Flash, builds up a high pressure in this chamber and is distributed over the entire scope of the tool shaft. From this small reservoir, coolant flows over the tool shaft directly as a closed jacket, making it insensitive to air turbulences. At the end of the shaft area, the coolant is pressed into the flutes, flushes them out and then reaches—even at high speeds—the cutting edges of the tool directly without atomizing.
The Haimer Cool Flash System offers an important advantage over other technologies. No additional sleeves or separate mounts are required for the best possible cooling, which normally involves an additional effort for the shrinking process. Haimer shrink chucks can also be shrunk in and out normally using the Cool Flash option. The stability, stiffness, and interference contour of the original Haimer chuck remain unchanged.
For more information on Haimer USA, go to www.haimer-usa.com, or telephone 630-833-1500.
Parts with Small Cross-Sections
For machining long parts with small cross-section for aerospace, construction, ship building, and wind-power industry applications, the E Mill HMC from MAG IAS can handle composites, titanium, and aluminum. The small footprint HMC features a feed/rotary drive that provides 360° machining of complex-geometry parts in a single setup. Typical workpieces include stringers, spars, beams, and similar parts.
The 500-mm, three-axis HMC performs contour machining, routing, drilling, and tapping to produce finished, complex, 3-D geometry parts with headstock and tailstock adapted from horizontal lathes to provide fourth and fifth axes of motion. The part manipulation system allows A-axis programmable rotation and 360° infinite positioning, while supplying V-axis linear travel for pull-through part feed. Work stock is loaded and unloaded from infeed and outfeed tubes. Made from a tough industrial plastic, the infeed and out-feed tubes are clamshell designs. The in-feed opens from the top for loading work stock, with the outfeed bottom opening for ease of part removal. The tubes are seamless extrusions to prevent abrasion and delamination of composite materials, while the enclosed design provides additional containment of cutting fluids, part chips, and dust.
The E Mill is available with a choice of a 16,000 or 24,000-rpm HSK63A spindle. Supporting single setup processing, a drum-style ATC accommodates 12 tools up to 8 kg each in weight, 200-mm long, and 125-mm diameter. The E Mill is equipped with full enclosure guarding, vacuum filtration, and mist/dust extraction for CE and OSHA compliance--especially important for machining composite materials. A pressurized way system protects against wear from abrasive composite dust.
The headstock/tailstock system features through-hole chucks with powered jaws, allowing the work stock to be advanced incrementally through the jaws. The "live" headstock travels on V-axis linear slides, letting it move next to the stationary tailstock, lock on the workpiece, then slide back, pulling the work stock along. The system provides 1089 mm of travel for incremental part indexing. The fully programmable feed system can accommodate work stock from 300 mm to 12 m in length and up to 304.8-mm square in cross section. The headstock moves on parallel guideways 775 mm apart, while the fixed tailstock offers a similar broad base to give stability for coordinated A-axis part rotation.
The E Mill design can be adapted to larger machining centers with more powerful spindles for processing harder materials. Besides cost savings over machining platforms with 12-m travel or more, the compact E Mill design saves valuable plant floor space, avoids fixture costs, and enables faster setup for reduced WIP.
For more information on MAG IAS, go to www.mag-ias.com, or telephone 859-534-4600.
ATC Alignment Tool
When automatically loading a toolholder, any misalignment of the ATC gripper to the spindle can cause damage to the spindle taper. A misaligned, clamped toolholder leads to increased runout, thereby shortening the life of the machine tool, cutting tool, and toolholder. The ATC Alignment Tool from BIG Kaiser Precision Tooling (Hoffman Estates, IL) allows operators to avoid such problems by making sure the ATC gripper aligns the tool with extreme precision, which prevents any collision and potential damage. The tool may also be used to align the ATC gripper to the magazine tool pockets.
Jack Burley, vice president-sales and engineering, points out that the ATC Alignment Tool functions as a preventative maintenance tool for operators, but also is useful during repairs, and even during the original machine and tool magazine setup. "It’s an indispensable accessory for machine tool repair and installation operators."
The tool features a built-in stylus that determines the high/low values when the plug is slowly rotated. The values are displayed on a 10 µm/div dial indicator and reveal the eccentric direction—half of the gap between the high and low is the eccentric amount. Such eccentricities would be otherwise imperceptible.
By providing fast, precise adjustments to keep the spindle taper free from damage and running true, the ATC Alignment Tool ensures long machine tool, cutting tool, and toolholder life while reducing stress on the spindle. The ATC Alignment Tool is the latest addition to BIG Kaiser’s portfolio of precision machine inspection, installation, and repair solutions, which also include the Dyna Test, Dyna Force, and Level Master.
For more information about the ATC Alignment Tool and other machine inspection, installation or repair solutions, from BIG Kaiser, go to www.bigkaiser.com, or telephone: 847-228-7660, e-mail email@example.com
Terahertz Polarizing Advances
Researchers at Rice University (Houston) are using carbon nanotubes as the critical component of a robust terahertz polarizer that could accelerate the development of new security and communication devices, sensors, and non-invasive imaging systems as well as advance fundamental studies of low-dimensional condensed matter systems. The polarizer developed by the Rice lab of Junichiro Kono, a professor of electrical and computer engineering and of physics and astronomy, is the most effective ever reported. It selectively allows 100% of a terahertz wave to pass or blocks 99.9% of it, depending on its polarization, according to a report in the online version of the American Chemical Society journal, Nano Letters.
The broadband polarizer handles waves from 0.5 to 2.2. terahertz, far surpassing the range of commercial polarizers that consist of fragile grids wrapped in gold or tungsten wires. According to Kono, technologies that make use of the optical and electrical regions of the electromagnetic spectrum are mature and common, as in lasers and telescopes on one end and computers and microwaves on the other. But until recent years, the terahertz region in between was largely unexplored.
"Over the past decade or two, people have been making impressive progress," Kono says, "particularly in the development of such sources of radiation as the terahertz quantum cascade laser. We have pretty good terahertz emitters and detectors, but we need a way to manipulate light in this range. Our work is in this category, manipulating the polarization state—the direction of the electric field—of terahertz radiation."
Terahertz waves exist at the transition between infrared and microwaves and have unique qualities. They are not harmful and penetrate fabric, wood, plastic, and even clouds, but not metal or water. In combination with spectroscopy, they can be used to read what Kono called "spectral fingerprints in the terahertz range, making them useful in a security setting to identify the chemical signatures of specific explosives, for example.
Kono’s lab began working with carbon nanotube arrays transferred onto a sapphire substrate using a technique developed by Robert Hauge, a faculty fellow in chemistry, and Hauge’s former grad student Cary Pint. They found a way to grow nanotube carpets and to transfer well-aligned arrays of nanotubes from a catalyst to any substrate they chose, limited only by the size of the growth platform. The solution involved making the polarizer thicker with a triple layer of carbon nanotube arrays on a sapphire base as the basis for a new type of terahertz polarizer. The next research challenge is providing only semiconducting type nanotubes in an array so that they can be manipulated with an electric field. Batches of nanotubes are currently a random mix of semiconductors and metallics. The Department of Energy, the National Science Foundation, and the Robert A. Welch Foundation supported the research.
To read an abstract of the paper, go to http://pubs.acs.org/doi/abs/10.1021/nl20378q
This article was first published in the April 2012 edition of Manufacturing Engineering magazine. Click here for PDF.