Bender for bending a workpiece with automatic springback compensation

A method of operating a bender to bend a workpiece to a desired target bend angle in a bending operation, the method comprising:

• sensing an initial position of a workpiece positioned within a groove of a bending shoe and gripped by a gripping member;
• bending the workpiece to only the desired target bend angle in an initial bending around a bending shoe by rotating the bending shoe in a first direction and sensing the bend angles of the workpiece during the initial bending;
• stopping the rotation of the bending shoe in the first direction when the desired target bend angle is sensed;
• thereafter determining an actual bend angle of the workpiece;
• thereafter rotating the bending shoe and gripping member in a second direction which is opposite to the first direction thereby allowing the workpiece to springback, wherein the workpiece is continued to be gripped by the gripping member during rotation in the second direction;
• stopping the rotation of the bending shoe in the second direction such that a new position of the workpiece is provided;
• thereafter sensing information regarding the new position of the workpiece and determining a sprungback bend angle at which the workpiece is bent;
• calculating a new bend angle at which the workpiece is to be bent to achieve the desired target bend angle, wherein the new bend angle is calculated based upon the sprungback bend angle and one of the actual bend angle and the first desired target bend angle;
• thereafter bending the workpiece to the new bend angle around the bending shoe by rotating the bending shoe and gripping member in the first direction with the workpiece being continued to be gripped by the gripping member and sensing the bend angles of the workpiece during the bending of the workpiece to the new bend angle;
• and
• stopping the rotation of the bending shoe in the first direction when the new bend angle is sensed.