Method of positioning a workpiece on a machine tool

A method for determining workpiece positioning in a machine tool, said machine tool having a loader mechanism including a means for gripping at least one workpiece, said loader mechanism being linearly movable along a loader axis by a linear drive means and being angularly movable about said loader axis by an rotary drive means, said linear drive means and said rotary drive means being part of a closed-loop positioning system for said loader axis, said method comprising:

• applying an first amount of electric current to the loader linear drive means, said first amount being reduced in comparison to a defined or predetermined full power amount of electric current for the loader linear drive means, whereby as a result of the reduced first amount of electric current, the loader linear drive means provides a respective output torque that is reduced in comparison to a defined or predetermined full power amount of torque for the loader linear drive means,
• applying a second amount of electric current to the loader rotary drive means, said second amount being reduced in comparison to a defined or predetermined full power amount of electric current for the loader rotary drive means, whereby as a result of the reduced second amount of electric current, the loader rotary drive means provides a respective output torque that is reduced in comparison to a defined or predetermined full power amount of torque for the loader rotary drive means,
• positioning a workpiece in a machine spindle of the machine tool and gripping said workpiece with the means for gripping of said loader mechanism whereby said loader mechanism and said machine spindle are mechanically coupled together, said machine spindle being movable along and/or about one or more spindle axes of motion with each of said axes of motion being associated with a respective spindle linear drive means and/or spindle rotary drive means wherein the spindle linear drive means outputs a torque at a defined or predetermined full power amount and/or the spindle rotary drive means outputs a torque at a defined or predetermined full power amount,
• wherein as a result of the reduced output torque of the loader linear drive means and the loader rotary drive means of the loader mechanism with respect to the full power output torque of the spindle linear drive means and/or the full power output torque of the spindle rotary drive means, said loader mechanism is repositioned linearly in a direction along the loader axis and rotationally about the loader axis whereby machine forces arising from the mechanical coupling are effectively neutralized.