Rotary draw machine

A method for bending a tube to a target bend angle at a bend location defined between leading and trailing tangents of the tube, comprising:

• causing rotation of a rotary bend die to a first die angle associated with the target bend angle to bend the tube at the bend location;
• causing rotation of the rotary bend die to retract the tube to disengage the tube to allow spring back of the tube;
• after causing rotation of the rotary bend die to retract the tube to disengage the tube to allow spring back of the tube, receiving data indicative of a leading angle, indicative of rotation of the tube at the leading tangent, and a trailing angle, indicative of rotation of the tube at the trailing tangent;
• and
• causing rotation of the rotary bend die to a second die angle to bend the tube to at least partially compensate for spring back, the second die angle being based on the first die angle, the leading angle, and the trailing angle.

A kit for a rotary draw machine to facilitate bending a tube to a target bend angle at a bend location defined between leading and trailing tangents of the tube, the rotary draw machine comprising a die-set to receive the tube and defining a rotary bend die that is actuatably rotatable to bend the tube, the rotary draw machine comprising a linear carriage assembly pivotably coupled to the die-set to support the tube and feed the tube to the die-set via the leading tangent, the kit comprising:

• a first rotation sensor suitable to be positioned to sense rotation of the tube at the leading tangent;
• a second rotation sensor suitable to be positioned to sense rotation of the tube at the trailing tangent;
• and
• a controller suitable to be operably coupled to the die-set, and suitable to be connected to the first and second rotation sensors, the controller configured to, when operably coupled to the die-set and connected to the first and second rotation sensors,
• cause rotation of the rotary bend die to a first die angle associated with the target bend angle to bend the tube at the bend location,
• cause release of the tube from the die-set to allow spring back of the tube,
• receive data indicative of a leading angle of the leading tangent from the first rotation sensor, after spring back of the tube, and a trailing angle of the trailing tangent from the second rotation sensor, and
• cause rotation of the rotary bend die, in response to the data, to a second die angle to bend the tube to at least partially compensate for spring back, the second die angle being based on the first die angle, the leading angle, and the trailing angle.