Article provided by MAPAL
The optimal machine tool plus the optimal tool equals the perfect combination. And that makes cost-effective processes and impressive machining results possible. One good example of this is the cooperation between the machine manufacturer, F. Zimmermann GmbH, and MAPAL. For demonstrations and machine acceptance tests, Zimmermann equips its new horizontal machining center with milling cutters from MAPAL.
F. Zimmermann developed its first HMC specially for the machining of structural parts for the aerospace industry. The aluminium structural parts, such as wing parts and frame ribs, are generally milled from solid material, with up to 95 percent material removal. Fault-free machining with respect to dimensional accuracy and surface finish is crucial here. And the component structure that becomes more and more delicate with increasing material removal represents an additional challenge.
To make the milling process as efficient as possible even in these areas, the new FZH machining center offers enhanced rigidity. For the core technology of the new 5- or 6-axis HMC is a robust, water-cooled traveling column. Whereas conventional machine concepts suffer from lever-related deviations with increasing slide, the guide carriage distance of the new Zimmermann machine increases with increasing plunging depth into the material. That actually increases the rigidity. To achieve maximum efficiency, Zimmermann employs its own patented M3ABC 3-axis milling head in the machining center. Particularly in the pocket corners of a workpiece, this milling head has to perform only small swivel movements, allowing the feed rate to be kept more or less constant and hence the machining time to be significantly shortened.
Dietmar Maichel (left), project manager 3D milling at MAPAL, and Steffen Nüssle, sales director export and head of applications engineering at Zimmermann, in front of the new FZH horizontal machining center. All photos courtesy of MAPAL
The beginning
At an open house in June 2017, Zimmermann demonstrated its new machining center with tools from competing toolmakers. These tools failed to meet the expectations, however, and were unable to exploit the performance of the machine. “Why not test the performance of the MAPAL tools?” thought the project managers at Zimmermann, as MAPAL was presenting its milling cutters for high-volume machining at the event. No sooner said than done. A short time later, representatives of the two companies carried out extensive milling trials with different tools together.
Working together for success ( left to right): Steffen Nüssle; Bernd Scheurenbrand, application engineer at Zimmermann; Norbert Meier, MAPAL field service; and Dietmar Maichel.
The milling cutters
“Our goal was to choose the optimum tools from our portfolio for the machining operations on the Zimmermann machine,” explained Dietmar Maichel, project manager 3D milling at MAPAL. The tool manufacturer’s portfolio contains different milling cutters for the different tasks during the high-volume machining of aluminium structural parts. The tools are designed for use on such high-performance machines as the Zimmermann machine. The SPM milling cutters are available in a solid-carbide design and with PCD and ISO inserts. A total of four tools are used at Zimmermann for the different demands of the roughing and finishing operations.
Analysis of the machining results directly at the horizontal machining center.
The interaction
“The perfect combination – the machine, the 3-axis milling head and the tools from MAPAL – give the user a real performance boost,” said a delighted Steffen Nüssle, sales director export and head of applications engineering at Zimmermann, immediately after the first tests. “With the SPM-Rough ISO shoulder milling cutter, we achieved the best results that we have ever achieved with a tool with indexable inserts.”
The ISO tools with polished indexable inserts are the latest addition to the MAPAL SPM product range. The SPM-Rough with wave profile also surpassed the expectations for material removal with smooth running. “The complete machining of a 190x190x40 mm pocket is now effectively possible in less than a minute,” explained Nüssle.
In combination, the MHC, the 3-axis milling head and the SPM-Rough ISO shoulder milling cutter achieved optimal results.
The present
The experts at F. Zimmermann GmbH are convinced by the MAPAL tools. “The use of the SPM milling cutters has given us a quantum leap forward in the aluminium machining. And it shows us what the perfect combination of tool and machine means in terms of performance,” said Nüssle. In the meantime, the tools are therefore first choice when it comes to machine acceptance tests or demonstrations for customers from the aerospace industry at Zimmermann.
The future
The Zimmermann machines are suitable not only for the machining of metals. “Many of our customers manufacture parts of composite materials,” said Nüssle. Zimmermann therefore also wants to mill trial parts of these materials using MAPAL tools. “We are optimistic that with the MAPAL milling cutters for composite machining, we will also find a new secret weapon to exploit the performance of our machines even better.” The corresponding plans are already in hand.
Key data of the tools used at Zimmermann (left to right):
- Roughing – solution for diameter ranges above 25 mm
SPM-Rough ISO shoulder milling cutter with indexable inserts
Diameter 40 mm – Feed rate 21 m/min – Material removal rate 6.9 l/min
10 percent lower cutting forces with the best surface finish compared with the milling cutters from competitors previously used.
- Roughing – solution for diameter ranges up to 25 mm
SPM-Rough solid-carbide milling cutter with wave profile
Diameter 25 mm – Feed rate 13 m/min – Material removal rate 7.3 l/min – Cutting depth ap 37.5 mm, cutting width ae 15 mm
High material-removal rates with the highest machining values.
- Multiple-stepped semifinishing of thin-walled structures
OptiMill-SPM solid-carbide milling cutter
Diameter 16 mm – Feed rate 12 m/min – Projection length 66 mm – Extremely sturdy thanks to conical form
Time savings of more than 40 percent are possible in combination with the 3-axis milling head.
- Finishing of deep pockets and delicate structures in a single pass
SPM-Finish solid-carbide milling cutter
Diameter 12 mm – Feed rate 3 m/min – Best surface finish – Cutting depth ap 40 mm – Special finishing geometry – No vibrations
Optimal results even with large machining depths and practically complete wrapping of the milling cutter.
Related Glossary Terms
- feed
feed
Rate of change of position of the tool as a whole, relative to the workpiece while cutting.
- gang cutting ( milling)
gang cutting ( milling)
Machining with several cutters mounted on a single arbor, generally for simultaneous cutting.
- machining center
machining center
CNC machine tool capable of drilling, reaming, tapping, milling and boring. Normally comes with an automatic toolchanger. See automatic toolchanger.
- milling
milling
Machining operation in which metal or other material is removed by applying power to a rotating cutter. In vertical milling, the cutting tool is mounted vertically on the spindle. In horizontal milling, the cutting tool is mounted horizontally, either directly on the spindle or on an arbor. Horizontal milling is further broken down into conventional milling, where the cutter rotates opposite the direction of feed, or “up” into the workpiece; and climb milling, where the cutter rotates in the direction of feed, or “down” into the workpiece. Milling operations include plane or surface milling, endmilling, facemilling, angle milling, form milling and profiling.
- milling cutter
milling cutter
Loosely, any milling tool. Horizontal cutters take the form of plain milling cutters, plain spiral-tooth cutters, helical cutters, side-milling cutters, staggered-tooth side-milling cutters, facemilling cutters, angular cutters, double-angle cutters, convex and concave form-milling cutters, straddle-sprocket cutters, spur-gear cutters, corner-rounding cutters and slitting saws. Vertical cutters use shank-mounted cutting tools, including endmills, T-slot cutters, Woodruff keyseat cutters and dovetail cutters; these may also be used on horizontal mills. See milling.
- milling machine ( mill)
milling machine ( mill)
Runs endmills and arbor-mounted milling cutters. Features include a head with a spindle that drives the cutters; a column, knee and table that provide motion in the three Cartesian axes; and a base that supports the components and houses the cutting-fluid pump and reservoir. The work is mounted on the table and fed into the rotating cutter or endmill to accomplish the milling steps; vertical milling machines also feed endmills into the work by means of a spindle-mounted quill. Models range from small manual machines to big bed-type and duplex mills. All take one of three basic forms: vertical, horizontal or convertible horizontal/vertical. Vertical machines may be knee-type (the table is mounted on a knee that can be elevated) or bed-type (the table is securely supported and only moves horizontally). In general, horizontal machines are bigger and more powerful, while vertical machines are lighter but more versatile and easier to set up and operate.
- polycrystalline diamond ( PCD)
polycrystalline diamond ( PCD)
Cutting tool material consisting of natural or synthetic diamond crystals bonded together under high pressure at elevated temperatures. PCD is available as a tip brazed to a carbide insert carrier. Used for machining nonferrous alloys and nonmetallic materials at high cutting speeds.
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