Bend Program Optimization

The goal of bend program optimization is to reduce the cycle time per part.

General Optimization Principle

Attempt to optimize motion through combination of motion.

Closely watch the bender during cycle to determine if there are any motions that can be combined. Determine if there are features already built into CNC Bender that will allow for this optimization. If not, then describe the optimization to Advanced Tubular programmers for consideration.

Specific Optimization Techniques for CNC Bender

FEED AND ROTATE Change the Feed THEN Rotate to Feed AND Rotate

The "AND" implies that Feeding and Rotation are performed together Set this option in the FEED option cells of the FRB page

POST BEND JOG Remove the Post Bend Jog move in each FRB Row The Post Bend Jog Enabled feature allows Post Bend Jogging to occur after a bend is complete. This jogging motion clears the bend from the bend die before the bend arm returns home.

This is the extra motion of the carriage just after a bend for the tube to clear the bend die. If the bend angle is very small, then removing this motion is probably possible If the bend angle return step angle is very high, then removing this motion may be possible

BEND RETURN STEP POINT Increase the Bend Return Step Point value in each FRB Row The Step Point controls when the next row's Feed and or Feed/Rotate begin moving in relationship to the returning bend arm. If the step point is set to 90, for example, then the Feed and Rotate will begin moving as soon as the bend arm is within 90 degrees of its target position of ZERO degrees.

Increase this value after observing the bend cycle at this bend. Determine if the Feed can come forward earlier without colliding with the dies in the returning bend arm. The value is set in the bend cell of the bend that just completed. Increasing this value will sometime enable the removal of Post Bend Jog motion

RADIUS SHIFTING DURING FEED Set Radius Shifting to occur DURING the FEED CNC Processor uses is ability to run multiple processes simultaneously to move the Feed, Rotate, and the RADIUS SHIFTING at the same time. While the feed and rotate are occuring, the radius can also be shifting in what is called a "secondary process".

Set this value in the Radius Option of the row that shows different radius than the previous row If the tube moves up or down without the carriage or bend head shifting the tube out of the die, then increase the Horizontal Radius Shift Offset to a higher value Enable the Simultaneous Vertical / Horizontal Shift option. This option allows the horizontal head axis and vertical head cylinders to move at the same time when the bend head is shifting radius levels. If necessary, enable the Radius Shift Delay to delay the start of simultaneous shifting for a millisecond duration after the Feed/Rotate axes begin moving. If necessary, enable the Early Radius Level Change Mode. This allows the tube to shift radius levels on any row before feeding/rotating. This means that vertical motion is applied, without shifting into the dies.

PRESSURE DIE RETRACT TIMER Set the Pressure Die Retract Timer to Enable This feature enables Pressure Die Retract timing rather than full pressure die open.

Set the Pressure Die to retract a short distance (PD Retract Timer = 100 ms) on bend rows that do move into radius shift rows You will need to determine what length of time will open your pressure die enough to free the tube for forward motion. The recommended mimimum starting time is 100 ms

EARLY MANDREL EXTRACTION Enable Early Mandrel Extraction option

Use this feature to extract the mandrel while coming to the end of a bend. Set the Early Mandrel Extraction Zone value. The value represents the number of degrees from the final bend angle where the mandrel should begin retracting. Extraction before 15 degrees from the final bend position may increase flattening in the bend. The goal is to allow the mandrel to complete the extraction at the same time or slightly before other actuators finish their motion. So this value does not have to be set higher than the value required to accomplish this goal.

EARLY MANDREL FORWARD Enable Early Mandrel Forward At Angle option

Use this feature to send the mandrel forward while the bend arm is returning. Take care that there is enough straight tube in front of ball mandrels in order to move the ball mandrel forward. The goal is to move the mandrel forward early without pressing the ball mandrels into the bent tubing.

HOLD MANDREL FORWARD Enable Hold Mandrel Forward

Use this feature if a plug mandrel is installed. This will save significant time for each bend. The option is enabled in each Bend Option cell on a per-bend basis. Draw the mandrel back on the last bend in order to make the part easier to unload.

--Mcone 11:31, 20 July 2006 (EDT)