National 1 Die 2 Blow

1 Die 2 Blow Image The following lesson outline details the tasks needed to be a machinist on a National 1 Die 2 Blow cold header. Some of these tasks require the trainee to explain how something works to insure they have the required understanding of the processes and are not simply memorizing procedures. All of the tasks listed will be a part of the Performance Test within each lesson. To learn more about these tests and the training process itself, see the Philosophy section.

This program was specifically designed to train setup operators of National One-Die Two-Blow cold headers, including sizes 3/16", No. 25, 1/8", 1/4", and 5/16". The instructional technique employed will enable individuals to learn to setup and operate the machines with little difficulty. Both existing personnel and new trainees can utilize these training materials to develop or improve their performance.

Lesson 1: Basic Operation and Blank Terminology [ Top ]

After completing this lesson the operator will be able to:

  1. Describe the basic operation of a cold header, including cutoff, transfer, and the operation of the heading slide and the punch and die.
  2. Explain common secondary operations performed on cold headed blanks, including threading, slotting, pointing and plating.
  3. Explain commonly used wire material and describe where the size and type of a wire coil can be found.
  4. Locate and identify components of a cold headed blank.
  5. Locate and identify commonly measured lengths, heights, diameters and angles on a cold headed blank.
  6. Identify head styles commonly found on blanks which are formed on top of the heading die.
  7. Identify head styles commonly found on blanks which are formed partially or totally within the heading die.
  8. Identify types of cross recesses formed during the heading operation.
  9. Select the proper measuring instrument for measuring blank features and angles, including micrometer, calipers, machinist's scale, head height gauge, runout fixture and indicator, and optical comparator.
  10. Using the information on a part print, determine whether blank features are within tolerance.
  11. Identify flaws in headed blanks such as burrs, flashes, seams and cracks.

Lesson 2: Basic Header Controls and Functions [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify and explain the purpose of all operator controls and indicator lights on the header.
  2. Locate, identify and explain the purpose of machine components used during normal operation and jogging.
  3. Start the lubrication pump, properly set the operator controls, then start the header into normal operation.
  4. Stop normal operation using either the red STOP button or the Run/Jog selector switch.
  5. Jog the header in the forward direction.
  6. Stop and start the feeding of wire stock using either the Wire Feed lever or Feed Off and Feed On pushbutton controls.
  7. Jog the header in reverse after stopping the feeding of wire.
  8. Explain the causes of automatic machine shutoffs, and describe what to do about them.
  9. Manually roll the header through a cycle or partial cycle by turning the flywheel by hand.
  10. Increase or decrease the length of wire fed into the header by turning the Feed Length Adjusting Knob.
  11. Adjust the cutoff length by turning the Stock Gauge Adjustment Knob.
  12. Visually inspect the Adjustable Oil Distributors to be sure that they are providing proper lubrication.
  13. Use the Feed Roll Pressure Wrench to start and stop the feeding of wire, and to adjust the amount of feed roll pressure on the wire.
  14. Inspect the lubrication oil level in the machine, and add oil if required.
  15. Wear the proper safety attire, including eye and ear protection, and use all safety and protective devices while operating the header.

Lesson 3: Wire Drawing [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify and explain the purpose of operator controls on the wire drawer.
  2. Locate, identify and explain the purpose of components of the wire drawer which feed and draw the wire.
  3. Explain how the Compensator Arm, micro-switch, and Compensator Wheel work to control the operation of the wire drawer.
  4. Inspect and measure a new wire coil, and compare the mill tag information to the part print to be sure it is the correct type and size.
  5. Adjust the speed of the wire drawer drum, using the Vari-Drive control, until the red feed light stays on.
  6. Prepare the coil for loading into the wire drawer by straightening the end, then grinding the first 1 1/2 feet to reduce the diameter. The draw die will be used to make sure that the diameter is properly reduced.
  7. Remove and replace the draw die in the draw box.
  8. Run the ground end of the wire through the draw box, add drawing compound to the draw box, use the gripper chain to draw out a couple of feet of wire, then check the diameter of the wire and inspect for scoring.
  9. Draw out the first wrap of wire, release the tension by jogging the wire drawer in reverse, and position the wrap by hand.
  10. Continue drawing using the gripping chain until ten wraps of wire are on the wire drum in preparation for loading the end of the coil into the header.

Lesson 4: Restocking the Header [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify and explain the purpose of feed components including the wire guide, feed tube, quill and wedge screw assembly.
  2. Safely remove the gripper chain from the end of the wire on the wire drum.
  3. Thread the wire from the drawer drum around the compensator wheel into the wire straightener, wire guide, feed rolls, and feed tube.
  4. Explain the results of too little feed roll pressure and too much feed roll pressure.
  5. Adjust the feed roll pressure using the pressure bar wrench until the pressure is correct on the wire and there is equal spacing between the feed box and the pressure bar at both ends of the pressure bar.
  6. Adjust the center lock nuts on the pressure bar to provide the proper clearance between the lock nuts and the pressure bar.
  7. Remove, clean and store the feed rolls and feed tube.
  8. Select the proper feed rolls for a given wire diameter, then install the feed rolls using a washer for alignment if double-groove feed rolls are used.
  9. Install the feed tube, then use straightened wire clamped in the feed rolls to align the feed tube.
  10. Remove and replace the quill after the split die block has been removed (split die block removal is shown in a later lesson).
  11. Adjust the first four rollers on the wire straightener to provide the proper straightening pressure on the wire.
  12. Adjust the last roller on the wire straightener to align the wire coming from the straightener with the feed tube near the feed rolls.

Lesson 5: The Header Die and Kickout [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify and explain the purpose of components of the split die block and the header die assembly.
  2. Inspect the die radius before installation of the die into the machine.
  3. Disconnect air fittings, loosen and remove the wedge, remove the wedge half of the die block, then remove the header die assembly.
  4. Remove the quill half of the die block after pulling out the pusher to provide clearance.
  5. Compare the length of the old die to the length of the die to be installed, then add or remove the proper amount of die packing to provide equal length.
  6. Make a kickout pin of the proper length from tool steel, and peen the end correctly.
  7. Replace the quill half of the die block and install the die and kickout pin assembly, then replace the wedge half and snug the die clamp screw against the notch in the die.
  8. Install the wedge and drive in to compress the die block around the die, making sure that the wedge lock screw does not contact the machine.
  9. Adjust the position of the air ejector nozzle to provide an air stream on the ejected blank, install a spring-loaded felt wick if required, and replace the pusher and air fittings.
  10. Locate, identify and explain the purpose of components of the kickout mechanism, describe the actions of these components during the kickout cycle, and identify the retracted position and the kicked position.
  11. Using wire marked with the proper length, adjust the kickout for the retracted position when going to a shorter workpiece by adjusting the kickout backing screw and shoe adjusting screw.
  12. Adjust the kickout for the kicked position when going to a shorter workpiece by adjusting the cam breaker bolt until the kickout pin comes flush with the face of the die in the kicked position.
  13. Adjust kickout for the retracted position when going to a longer workpiece.
  14. Adjust kickout for the kicked position when going to a longer workpiece.

Lesson 6: Cutoff and Transfer [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify and explain the purpose of components of the feed, cutoff and transfer mechanisms.
  2. Explain the length of wire which is considered a short feed, and the length which is considered a long feed.
  3. Rough adjust the stock feed by pinning the feed connecting rod in the hole on either the upper part or the lower part of the feed arm, depending on whether a short feed or a long feed is required.
  4. Select the correct stock gauge tip for either a short feed or a long feed, and install it in the machine.
  5. Describe the proper conditions for a good quality cutoff, including the sharpness of the cutter insert and quill, alignment of the cutter opening and the quill, and the clearance between the cutter and quill.
  6. Select the proper cutter insert and quill for a particular wire diameter.
  7. Remove the cutter and install a cutter for a setup, making sure that the hardened washer is properly seated.
  8. Align the cutter opening with the quill opening using the vertical adjusting sleeve and the horizontal adjusting screw, until a piece of wire of the correct diameter freely passes through the cutter insert and quill.
  9. Calculate and adjust the clearance between the cutter and quill for optimum cutoff quality.
  10. Adjust the pusher until it is flush with the face of the cutter, when the pusher is advanced as far as it will go into the cutter.
  11. Remove the transfer head, select the proper fingers for the diameter and length of cutoff stock, install the fingers on the transfer head placing the finger with the flat end on the bottom, properly position the fingers, then replace the transfer head in the machine.
  12. Adjust the finger gripping pressure to provide enough but no more pressure than is needed to hold the cutoff wire during transfer.
  13. Use a sample wire to align the fingers to the die; then test the alignment by jogging the machine to cutoff and transfer a piece of wire to make sure that the wire enters the die freely.

Lesson 7: Setting Punches and Timing [ Top ]

After completing this lesson the operator will be able to:

  1. Identify and explain the purpose of punches and punch components, including Standard First Blow punches, Sliding First Blow punches, Finish punches, and components of punch assemblies.
  2. Locate, identify and explain the purpose of machine components used when installing and adjusting punches, and adjusting punch and transfer timing.
  3. Remove the punches from the machine, compare the punch lengths to the lengths of the punches to be installed for the setup, then add or remove packing or shims as needed to achieve the same punch length when installed.
  4. Remove the punch holders from the machine; adjust the centering of the centering block to the punch holders using the adjusting screws until the side clearance is equal on both sides.
  5. Install punch holders in the machine, making sure that the dowel pins fit into the holder and the centering block and that the punch holder fits squarely against the punch rocker.
  6. Adjust the first blow punch by jogging the machine to shear and punch a blank, then adjusting the punch horizontally and vertically until the upset portion of the blank is concentric to the rest of the blank.
  7. Adjust the finish punch by punching a blank, then adjusting the punch until the upset portion of the blank is concentric to the rest of the blank.
  8. Adjust the punches closer to the die by raising the punch rocker wedge.
  9. Adjust the punches away from the die by lowering the punch rocker wedge.
  10. Place a sample wire in the machine and jog until the wire is in control of the punch and die, making sure the punch does not contact the fingers.
  11. Position the transfer cam to achieve the proper transfer timing, making sure that the fingers retract before being hit by the punch.
  12. Explain the difference in the amount of upset material between jogging speed and full operating speed, and compensate for the difference by under filling the die at jogging speed.

Lesson 8: Operation and Part Trouble Shooting [ Top ]

After completing this lesson the operator will be able to:

  1. Explain the proper corrective action for the following feeding problems:
    1. Incorrect size feed rolls
    2. Feed rolls slipping
    3. Excessive feed roll pressure
    4. Worn feed rolls
    5. Wire reel binding
    6. Wire with excessive kinks
    7. Straightener rolls too tight
    8. Quill and cutter not aligned
    9. Dirt built up in feed tube and quill
    10. Loose stock gauge tip, quill, and cutter
  2. Explain the most likely causes of the transfer fingers dropping the blanks.
  3. Explain the proper corrective action for the following causes of broken punch holders, fingers or punches:
    1. Broken fingers caused by striking fingers
    2. Sheared wire striking transfer fingers
    3. Play between punch and holder
    4. Punch not square on the end that fits into the punch holder
    5. Workpiece too far out of alignment with punch
  4. Explain the most likely causes of a distorted cutoff on the end of the blanks.
  5. Explain the proper corrective action for the following causes of headed parts with heads off-center, scored, cracked or bent:
    1. Improperly aligned punch and die causing head to be off center
    2. Excessive play between the punch and punch holder
    3. Excessive clearance between the wire and die opening
    4. Trying to upset too much material with one blow of the punch
    5. Improperly aligned transfer at the die causing score marks
    6. Undersize die opening scraping the wire causing score marks
    7. Inconsistent part body caused by die hole too large or wire too large for die
    8. Undetected seam in wire causing cracks or splits in finished parts
    9. Parts not clearing the work area
    10. Workpiece sticking in the punch
    11. Workpiece sticking in the die
    12. Workpiece sticking in the punch caused by wire diameter too small or the die opening diameter too small
  6. Explain the most likely causes of broken kickout pins.
  7. Describe two procedures which may be used to unstick the header.

Lesson 9: Relieving Knockout and Knockout in the Punches [ Top ]

After completing this lesson the operator will be able to:

  1. Identify the components of the relieving knockout attachment on the cold header and explain how the attachment operates.
  2. Disengage the relieving knockout attachment by moving the adjusting knob all the way down and setting the cam lever so that it does not contact the cam.
  3. Engage the relieving knockout attachment by moving the adjusting knob up and setting the cam lever so that it contacts the cam.
  4. Measure the amount of relief provided by the relieving knockout attachment by placing a wire sample in the die with the relief cam at the lowest position, marking the wire at the face of the die, moving the relief cam all the way up, and marking the wire again.
  5. Rough adjust the relieving knockout attachment for a specific amount of relief by turning the adjusting knob on the attachment, using a marked wire sample to measure the amount of relief.
  6. Fine adjust the relieving knockout attachment at production speed.
  7. Identify the components of the knockout in the punch attachment and explain how the attachment operates.
  8. Disengage the punch knockout attachment by turning the cam lever roller adjusting nut to a point where the roller does not contact the cam, then removing the knockout lever from the punch area of the machine.
  9. Engage the punch knockout attachment by installing the knockout lever in the punch area, and by moving the adjusting nut so that the cam roller contacts the cam during a complete cycle.
  10. Rough adjust the punch knockout mechanism by moving the adjusting screw in the front lever of the attachment against the kickout lever, at a point in the heading cycle when the punch and die are solid against an upset blank.
  11. Fine adjust the punch knockout attachment at production speed.

Lesson 10: Automatic and Manual Lubrication [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify by name and explain the purpose of all lubrication components of the machine, including components of the main lubrication system, the cone tool mist lubricator and the wire lube bath.
  2. Locate and identify types of lubrication fittings, including oil cup fittings, oil ball valve fittings, and zerk fittings.
  3. Explain how often regular lubrication tasks should be performed: inspecting the mail oil reservoir level, lubricating the manually oiled locations, and greasing the zerk fittings.
  4. Locate and clean the oil strainer.
  5. Start up the main lubrication system, making sure that the pressure reaches the correct p.s.i.
  6. Remove and replace the oil filter, clean the filter shell, reassemble the filter components and add oil as needed.
  7. Properly adjust the adjustable oil distributors.
  8. Setup and adjust the cone tool mist lubricator.
  9. Locate and lubricate all machine locations which require filling an oil cup, filling a ball valve, or hand oiling.
  10. Locate and grease all zerk fittings on the machine.