Method and device to ascertain a quality of a product obtained by subtractive manufacturing

A method to achieve a desired quality of a product, which product has been obtained by operation of a tool of a subtractive manufacturing device that removes material from a workpiece by cutting or drilling the workpiece, the method comprising the steps of:

• determining at least one relationship between a test force generated by an external force actuator acting on the tool and a deflection of the tool of the subtractive manufacturing device;
• after completion of the prior step, using a force sensor configured to measure forces applied in at least three orthogonally related directions to measure a first actually exerted machining force applied to the workpiece by the tool of the subtractive manufacturing device;
• automatically determining a machining force reference for said actually exerted machining force that was measured, wherein the machining force reference is determined as a magnitude of an actually exerted machining force that is exerted on the workpiece and remains stable during a predetermined evaluation time;
• automatically evaluating whether said actually exerted machining force deviates from said machining force reference;
• if an actually exerted machining force equals said machining force reference, then the desired quality of the product is deemed to have been achieved and operation of the tool to remove material from the workpiece by cutting or drilling the workpiece is terminated;
• if an actually exerted machining force deviates from said machining force reference, then using said at least one relationship between a test force generated by the external force actuator acting on the tool to automatically determine at least one correction deflection of said tool of the subtractive manufacturing device for changing said first actually exerted machining force to a second actually exerted machining force;
• and
• automatically creating at least one corrected drive control signal to fully or partially reduce said at least one correction deflection.