OPMT is a relatively small but fast-growing company based in Fo’shan – of Guangdong Province – in south China. It is rapidly acquiring a reputation for innovative complex engineering: after developing a highly successful 4-axis milling centre for an automotive production line, it then created a compact 5-axis milling station for the dental industry.
For its latest project, OPMT was asked by Guangdong University of Technology to develop a machining centre that combined high speed laser cutting and milling capabilities. This key provincial university is located in Guangzhou, Guangdong Province, China, and provides a wide range of courses, with a major emphasis on engineering. OPMT chose to partner with NUM for its CNC expertise and with the Xi‘an Zhongke Microcrystalline Manufacturing Company and the Chinese Academy of Sciences to help with some of the complex materials processing issues.
The result is the ML125 8-axis multi-function machining centre. The machine has a dual laser head that is capable of switching between a 20 watt picosecond laser for very high speed cutting and an ultrafast 10 watt femtosecond laser for improved process quality. The femtosecond laser is capable of drilling and cutting almost any type of material, and its very short 1030 nm wavelength means that it is suitable for micro/nano processing applications.
Entirely controlled by NUM’s latest-generation Flexium+ 68 CNC platform, the ML125 machining centre has eight servo axes, two independent NC channels and fast application-specific I/O embedded in the NCK hardware. Movement of the fully articulated laser head is controlled by five NUMDrive X servo drives, with high speed interpolation between all five axes – and the CNC system provides a full RTCP function.
By employing a special hollow shaft torque motor and a linear motor drive, the dual laser head has an exceptionally high positional accuracy of 8 micrometres (0.008 mm), with a repeatability of just 5 micrometres. The associated A/C axis rotation platform has a precision rotary feed function with a positional accuracy of 5 arc minutes. The milling head uses a 40,000 rpm spindle motor, and laser cutting and milling can be performed with just one clamping operation, which further improves process accuracy.
According to Bruce Zheng, CEO of OPMT, “The requirements of the industrial processing market keep changing, which means that our machines need to be extremely flexible so that they always offer customers what they need. Partnering with NUM helps us to achieve this; its open architecture CNC systems are easy to integrate with third-party products such as motors, and the company is prepared to offer the long term commitment and technical support that is necessary for successful completion of complex machine projects.”
The ML125 machining centre is now installed in a research laboratory at Guangdong University of Technology.