A TOOL DEFLECTION COMPENSATION SYSTEM FOR END MILLING ACCURACY IMPROVEMENT

In an effort to reduce machining surface errors due to tool deflection in the end milling process, methods regulating cutting forces have be en implemented with online feed rate controls. Such schemes are able t o improve the parts dimensional accuracy, but unfortunately they can e xhibit undesirable aspects in which the alleviation of the cutting con ditions deteriorates the productivity. In addition the frequent change s of the feed rate would spoil the surface quality. As a new approach to achieve the precision machining efficiently, this paper introduces a tool deflection compensation system. This compensation system is a c omputer controlled special tool adapter which is capable of measuring the cutting forces and minutely adjusting the position of the tool wit hout interfacing with the NC controller of the milling machine. Such a system allows for on-line estimation of the teal deflections and redu ction of the surface errors. Experimental investigations for typical s haped workpieces representing various end milling situations are perfo rmed to verify the ability of the system to suppress the surface error s due to tool deflections in more productive machining condition.