Thermal displacement is often the cause of precision problems on the workpiece
In modern high-speed drive spindles, thermal expansion of the spindle shaft is the main reason for thermal displacement of the machine tools. In the case of 5-axis machine tools this affects every side that is machined. The resulting error can double under circumstances. Compensation models integrated in the controls and which only operate with temperature sensors respond sluggishly and in some cases too late at rapidly changing speeds and temperatures. The result is over or under-compensation, which worsens the result. Accurate restarting on the contour following a tool change or manual measurement is often only possible with an appropriate warm-up period of the spindle.
The solution: integration of the spindle displacement sensor
By integrating a spindle displacement sensor at the expansion source, this can be measured accurately and compensated electronically. In this case, the cover plate of the milling head housing is changed, the sensor integrated and wired to the controls. The effective expansion of the spindle is transmitted in sync to the controls and compensated by applying a temperature compensation formula. The longitudinal expansion of swiveled planes is also compensated corresponding to the alignment of the milling head.