Indirect cutting force measurement considering frictional behaviour in a machining centre using feed motor current

In machine tools, friction exists between the table and the guideways, and in ballscrews. In this paper feed motor current is measured by a hall effec t current sensor. It is used to calculate the motor torque which, in him, i s the frictional torque at steady state. Some frictional phenomena are stud ied in feed drive systems of a horizontal machining centre, such as the rel ationship between feedrate and frictional torque, the relationship between frictional torque and table feed position, and the slideway cover effects o n frictional torque Considering all these frictional phenomena, the relatio nship between the feed force and the feed motor current is obtained. Feed f orce can be estimated well from the feed motor current considering friction al behaviour The relationship between the cutting force and the feed motor current is slightly different during up milling and down milling, because y (vertical) directional cutting farce changes the frictional force.