A new series of horizontal machining centers from Makino is recommended as a faster, more efficient approach to processing aluminum aerospace structural parts — specifically large, thin components, like wing spars, wing panels, and floor beams. The new A-Series includes the A4, A8, A12 and A20, each one positioned for processing specific part lengths in the range from 4 meters to 20 meters.
“Makino’s MAG-Series established the company as a leader in aerospace aluminum machining technologies,” explained David Ward, “and since its release, we’ve continued to improve and expand upon our capabilities. Ward is the horizontal product line manager for Makino, which designs advanced CNC centers for high-precision metal-cutting and EDM machining, including HMCs, VMCs, 5-axis machining centers, graphite machining centers, and wire and Ram EDMs.
“With the A-Series, we’ve focused on maximizing the average metal-removal rate throughout the machine process, improving spindle capabilities for heavy roughing, and optimizing linear and radial axis acceleration for pocketing and wall finishing,” he continued. “The result is a fast, highly accurate, highly predictable, 5-axis aluminum machining center.”
The standard A-Series machines are equipped with a 33,000-rpm HSK-F80 spindle featuring a high-power output of 107 hp (80 kW). At peak power, the A-Series spindle will achieve chip-removal rates up to 5,600 cm3/min (300 in3/min), according to the machine builder.
Workpiece accessibility, size and weight specifications for the four models of the A-Series are:
|
|
X-, Y-, Z-axis travels |
max. workpiece |
max. weight |
|
A4 |
4,200 x 2,200 x 650 mm |
4,000 x 2,200 x 500 mm |
3,750 kg |
|
A8 |
8,200 x 2,200 x 650 mm |
8,000 x 2,200 x 500 mm |
5,000 kg |
|
A12 |
12,200 x 2,200 x 650 mm |
12,000 x 2,200 x 500 mm |
7,000 kg |
|
A20 |
20,200 x 2,200 x 650 mm |
20,000 x 2,200 x 500 mm |
10,500 kg |
The A-Series spindle is augmented by a compact, fully integrated A and C axis design. With plus or minus 110 degrees of tilt in the A-axis, and a C-axis that is described as having “an infinite degree of rotation,” the spindle and head design allows 5-axis roughing and finishing capabilities along with excellent part accessibility for deep pockets and side walls.
Another standard feature of the A-Series machines is a FEA column design that reduces the overall weight while maintaining rigidity. Movement of the column along the X-axis is powered by eight linear motors, with 0.8-G acceleration. An extra-wide column base and dual-supported ball screws in the Y-axis ensure stability of the column and spindle during rapid axis movement.
The A-Series machines are invested with Makino’s Volumetric Accuracy Compensation technology, which provides in-process tool-tip corrections for sustained dynamic accuracy even in complex three-dimensional geometries.
These machines can be equipped with an optional 120-kW spindle, according to Makino. This spindle maintains the same maximum rpm of 33,000 but reportedly will deliver 50 percent more power, enabling increased metal-removal roughing rates to as much as 6,550 cm3/min (400 in3/min) in aerospace-grade aluminum.
Complementing the additional power, this spindle also provides through-spindle coolant capability, a first for the MAG-Series spindle design. With a through-spindle coolant pressure of 1.5 MPa, or 217 psi, this is an especially important function for evacuating chips during pocketing and reducing pecking requirements, for improved drilling efficiency. Manufacturers also benefit from extended tool life that results from direct tool cooling and greater cutting lubricity.
The A-Series has an advanced spindle that also features Makino’s third generation of Autonomic Spindle Technology (AST3). With AST3, the spindle uses displacement sensors to monitor forces against the spindle. During machining, the data from these sensors is evaluated in real time. If an unsafe load condition is detected, the AST3 reduces the feed rate to prevent damage to the spindle and tooling.
