A mechanically controlled rotary transfer machine can produce parts faster than a CNC one because there is no inversion of a stepping motor like on an NC axis. However, a CNC one—where all axes are programmable—significantly reduces the downtime that occurs when switching from one part to another because changeover is done primarily through software programming. “You can freely program your speeds and feeds to use other tools,” said Oskar Weder, general manager and CEO of Mikron Corp. Monroe. “Programming on the CNC machine is much simpler than making a cam and mounting it on a machine.”
To more closely bridge the mechanical/CNC gap in output capability while offering the flexibility to do part volumes of even a few hundred, including parts as small as 0.8mm, the machine tool builder and toolmaker introduced the Multistar NX-24 CNC rotary machining system. According to Mikron, the machine is slightly less productive than a mechanical one but the control’s operator interface simplifies rapid programming and changeovers. For instance, it might take 12 hours to change from one part to a significantly different one on a mechanical machine, Weder noted, but only 4 hours on the Multistar.
Courtesy of Mikron SA Agno
A blank is fed into the Multistar NX-24 CNC rotary transfer machine’s first workstation and clamped in the collet (above), and the completed part is unloaded from the machine in the last station. Below: End users can produce a variety of parts on the machine.
A unique feature of the Multistar NX-24 is its 24 workstations (22 for machining, one for clamping the workpiece in the collet and one for ejecting the finished part). The machine also has 44 machining units and 60 axes. All axes work simultaneously, which is how the machine achieves its high output. “It’s quite a marvel—there are so many axes working simultaneously,” Weder said.
In addition to the workstations machining simultaneously, each workstation can machine two sides of a part at the same time: from above and below, from above and from one side or from below and from one side.
The Multistar offers a maximum spindle speed of 32,000 rpm, which is effective for applying microtools, such as Mikron’s 0.7mm-dia. through-coolant CrazyDrill, according to Weder. “This machine has the capability,” he said. “The spindles are extremely accurate and smooth running.” Part accuracies are in the hundredths of a millimeter range, the company reports.
For more information about Mikron Corp. Monroe, Monroe, Conn., call (203) 261-3100 or visit www.mikron.com.
Related Glossary Terms
- collet
collet
Flexible-sided device that secures a tool or workpiece. Similar in function to a chuck, but can accommodate only a narrow size range. Typically provides greater gripping force and precision than a chuck. See chuck.
- computer numerical control ( CNC)
computer numerical control ( CNC)
Microprocessor-based controller dedicated to a machine tool that permits the creation or modification of parts. Programmed numerical control activates the machine’s servos and spindle drives and controls the various machining operations. See DNC, direct numerical control; NC, numerical control.
- computer-aided manufacturing ( CAM)
computer-aided manufacturing ( CAM)
Use of computers to control machining and manufacturing processes.
- numerical control ( NC)
numerical control ( NC)
Any controlled equipment that allows an operator to program its movement by entering a series of coded numbers and symbols. See CNC, computer numerical control; DNC, direct numerical control.
- rotary transfer machine
rotary transfer machine
Type of CNC machine tool for high-volume, extended-length production runs of a family of parts. A workpiece is transferred from station to station in a rotary fashion and a tool or tools at each station performs one or more operations until the part is completed.
Author
Alan holds a bachelor’s degree in journalism from Southern Illinois University Carbondale. Including his 20 years at CTE, Alan has more than 30 years of trade journalism experience.
