Spindle Options Maximize Machine Capabilities

March 22, 2012
Heller introduces HMCs for aerospace alloy machining
Heller F series horizontal machines for 5-axis simultaneous machining offer three high-performance spindle options for different cutting conditions and part configurations. Heller machines are available with table sizes from 500 to 1,000 mm; strokes from 630 to 1700 mm, several spindle options, with speeds ranging from 6,000 to 16,000 RPM. Machines have spindle horsepower to 43 kW and torque ratings of 89 to 822 NM. Heller F Series machines use HSK 63 tools. The heavier-duty, MCH–C Series machines use HSK 100. Titanium and nickel alloys are widely used throughout aerospace manufacturing, but the high strength of titanium results in high thermal stress and wear of the cutting edge during machining. For that reason, high torque and low speed are critical factors for effective aerospace milling operations.

The versatile Heller F series HMCs for 5-axis simultaneous machining comes with three high-performance spindle options for different cutting conditions and part configurations. Each Heller machine delivers high torque at low speeds during milling, including simultaneous machining in five axes, ideal for complex contouring. Heller’s new F-2000 5-axis machining center with swivel head includes several components from Heller's modular machining centerline, with a large working area of 800×800×1000, (X, Y, Z). It can accommodate a 630-mm pallet and 3,080-lb workpiece.

With three different high-performance spindles, the line offers options to machine smaller, lighter parts, frequently of tough material such as titanium, and aluminum parts that require high-speed machining.

The swivel-head provides a fifth axis that delivers a constantly high cutting performance in horizontal and vertical position, as well as any spatial angle— which is particularly important for aerospace machining. The 5-axis kinematics provided by the tool in X, Y, C, or A, and two axes provided by the workpiece in the Z and B axis, provide high precision, machining versatility, and high dynamics.

“After intensive market research, Heller engineers determined that the most flexible, robust, and efficient way to do 5-face and 5-axis machining is to have one of the axes in the work head,” according to the developer — which is Germany’s largest producer of horizontal machining centers, as well as crankshaft milling and turning systems.

“Using a B-axis table in combination with a universal or tilting work head allows greater table loads, larger working envelops and greater accessibility than 5-axis machines that have two axes of motion under the workpiece, such as a tilt/rotary table or C-over-B type,” Heller continued.

The machine structure and axis design have been tailored to the specific requirements of 5-axis machining and it includes a HSK63 spindle taper and 242 Nm torque has been specifically designed for high performance.

Three high-performance spindles
The core of the F series design is the innovative spindle technology. The PCU 63 is for high-performance cutting with speeds up to 10,000 RPM, power up to 44 kW and torque up 244 Nm. Two other spindles — the SCU 63 and the SCT 63 Tilt spindle — run at up to 16,000 RPM with 40 kW of power and 80Nm of torque. The SCT-63 is an A-axis head, in contrast to the others that are C-Axis. The A-axis provides even more flexibility in cutting complex shapes.

The two swivel-head units offer several advantages for complete machining of cubic parts in a single set-up, and the tilting head is best for machining contoured surfaces of any kind, thus making it a solid option for 5-axis simultaneous machining, especially for aerospace applications.

Using the swivel spindle with HSK63 spindle taper saves operating cost and achieves smoother performance during machining. As a result, a high-quality surface finish and a significantly longer tool life and higher process stability can be achieved.

“Obviously, our customer industries have wide and varying applications, so the Heller consultative process is quite effective for the user. Because we are not a ‘one-size-fits-all’ builder, we work with our customers to be sure we configure F Series machines based on the type of work to be done, the production requirements, the material to be machined, and the type of CAD/CAM system used by the customer,” stated Vincent Trampus, Heller Machine Tools L.P.’s vice president of sales.

The powerful and structurally solid machine set-up can achieve a high cutting performance that results in high chip removal rates, while providing precision in the µm range.

To assure machining precision, the F Series machines use a coded direct measuring system, high-resolution rotary encoders, and YRT bearings with integrated measuring system.

About the Author

Robert Brooks | Content Director

Robert Brooks has been a business-to-business reporter, writer, editor, and columnist for more than 20 years, specializing in the primary metal and basic manufacturing industries. His work has covered a wide range of topics, including process technology, resource development, material selection, product design, workforce development, and industrial market strategies, among others. Currently, he specializes in subjects related to metal component and product design, development, and manufacturing — including castings, forgings, machined parts, and fabrications.

Brooks is a graduate of Kenyon College (B.A. English, Political Science) and Emory University (M.A. English.)