Accelerating assembly checks: CMM Inspection

The ultimate accuracy and reliability of a machine tool depends in no small degree on alignment checking during the building process. For machine tools produced in high volumes, the efficiency of the alignment checking process is paramount.

Seeking an alternative to traditional error measurement techniques, Hurco Manufacturing Ltd. in Taichung City, Taiwan, chose Wotton-under-Edge, U.K.-based Renishaw PLC’s XK10 alignment laser system to increase precision and throughput. (Hurco Cos. Inc. is in Indianapolis, and Renishaw Inc. is in West Dundee, Illinois.)

Hurco builds a variety of machine tools, including five-axis CNC machines, multiple-axis CNC lathes, vertical machining centers and turning centers. Its worldwide customer base includes tool, mold and die makers; job shops; short-run production manufacturers; and original equipment manufacturers of metal fabrication tools. The product portfolio contains three brands: Hurco, Milltronics and Takumi.

To ensure that requirements for machine tool precision, safety and reliability are met, strict quality control is critical for each step in the building process.

Hurco uses the XK10 alignment laser system for machine tool assembly, calibration and maintenance. Photo courtesy of Renishaw

With Hurco producing thousands of machine tools every year, increasing measurement efficiency was a vital driver for the company’s inspection and verification processes. Machine measurement and alignment needed to be highly accurate, as well as faster.

Hurco previously performed alignment inspections during the assembly process using a blend of traditional measurement tools, coordinate measuring machines and calibration equipment. The company had long employed a range of Renishaw products, including the XL-80 laser interferometer, QC20-W ball bar system and XR20-W rotary axis calibrator.

The sheer size of cast machine tool components presented significant restrictions for CMM solutions while the inherent weaknesses of traditional measurement techniques risked limiting operational performance.

“In the past, we have measured and aligned our cast products using coordinate measuring machinery, but the larger dimensions of cast parts were always a limiting factor and made it rather labor-intensive,” said Wang Shun-Chien, vice president of Hurco Manufacturing. “We would also use traditional error-checking tools like granite squares, dial gauges and autocollimators during the assembly process, but these were never efficient enough, and the measurement results were too inconsistent. When we needed to measure the parallelism of some large cast parts, if the granite square and guide rail are a distance away, then the dial gauge needed to be extended to reach the granite, which would then cause any deviation result to amplify.”

As a result, the company sought a more accurate machine tool alignment solution that would be less time-consuming and labor-intensive to set up and use and could replace the traditional measurement methods.

Following extensive research and testing, Hurco adopted the XK10 alignment laser system. The XK10 can be applied to linear rails to ensure they are straight, square, flat, parallel and level, as well as to spindles and chucks to assess direction and coaxiality of rotary machines.