Thermal compensation to become standard for Mori Seiki machines

The function has been installed on an NL Series CNC lathe (pictured) and the company reports that it has succeeded in controlling thermal displacement to within 5 - 8 µm (actual test results) for a 10 °C change in the ambient temperature (over a 4-hour period). Without introducing offsets, axis displacement varied depending on the machine, but reached as high as 50 µm. The function measures the temperature using thermal sensors mounted on the bed and column, predicts the amount of displacement in realtime, and adjusts the position of the spindle or the turret to compensate. The NL2500 CNC lathe and the vertical machining center NV6000 DCG have adopted this function, and they will be on display at JIMTOF2006 held at Tokyo Big Site from 1 November, 2006. After that, it will be made available on the N Series machining centres and 12 models of CNC lathes. Mori Seiki says it will gradually install this new function as standard on its machines. Changes in ambient temperature are always a major problem. For example, iron has displacement of 12 µm per 1 m for every 1 °C of temperature increase. In order to control this displacement, a warming-up operation before machining and additional air conditioners to manage the factory temperature are generally required.