Davenport

Davenport Image The following lesson outline details the tasks needed to be a machinist on a Davenport automatic bar machine. 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 training system was specifically designed to accommodate the various stock size Davenport machines commonly found in use today. The instructional technique employed will enable individuals to learn to setup and operate the machines with little difficulty. The first 8 lessons cover the basic set up and operating tasks. The final 6 lessons cover installation and setup of specific attachments. Both existing personnel and new trainees can utilize these training materials to develop or improve their performance.

Lesson 1: Basic Controls and Components [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify by name, and explain the purpose for each of the major components of the machine including:
    1. Main Power Switch
    2. Main Motor
    3. Main Control Panel
    4. Motor Start Control
    5. Motor Stop Control
    6. Jog / Run Control
    7. Work Spindles
    8. Hand Wheel Mechanism
    9. Feed Start Lever
    10. Tool Swing Arms
    11. Cross Slides
    12. Work Chute
    13. Cross Slide and Tool Arm Cams
    14. Tool Spindle Cams
  2. Identify the sequence of events in the machining cycle. The following is included:
    1. Indexing
    2. Approach
    3. Feed Portion
    4. High Point or Dwell
    5. Drawback
  3. Locate and explain the following operations:
    1. Cutoff Operation and Position
    2. Stock Feed Operation
    3. Cross Slide Operation
    4. Tool Swing-Arm Operation
    5. Optional Position 4 Cross Slide
    6. End-working Tool Spindle Positions
  4. Explain the following end-working operations:
    1. Reaming
    2. Broaching
    3. Recessing
    4. Drilling

Lesson 2: The Stock Feed Components [ Top ]

After completing this lesson the operator will be able to:

  1. Locate and explain the purpose for the following stock feed system components:
    1. Stock Tube Carriers
    2. Stock Reel
    3. Feed Fingers
    4. Pusher Assemblies
    5. Collets
    6. Inner Spindle
    7. Stock Feed Lever
    8. Chuck and Feed Cam
    9. Cam Roller
    10. Stock Stop
    11. Feed Slide Safety Cam
    12. Collet Hand Operating Lever
    13. Chuck Lever Roll Throwout
    14. Chuck Slide Opening Guide Latch
    15. Stock Feed Adjusting Crank
  2. Explain the stock feed sequence of operation.
    1. Feed Lever pull-back
    2. Pusher pull-back over stock
    3. Collet opening
    4. Pusher forward stroke
    5. Collet closing
    6. Begin machining

Lesson 3: Pusher and Collet Removal and Replacement [ Top ]

After completing this lesson the operator will be able to:

  1. Place the machine at half index.
  2. Move Stock Carrier.
  3. Remove and clean the Pusher assemblies.
  4. Remove and clean the Feed Fingers.
  5. Select, clean, and install new Feed Fingers.
  6. Lubricate, replace and secure the Pusher assembly.
  7. Unlock chuck slide mechanism.
  8. With collet wrench, loosen and remove collet.
  9. Clean spindle.
  10. Clean and replace collet.
  11. Hand crank to complete index, load bar end in collet.
  12. Set collet tension using hand operating lever.
  13. Replace pusher and reposition stock carrier.

Lesson 4: Adjusting Speed and Feed [ Top ]

After completing this lesson the operator will be able to:

  1. Name, locate, and state the purpose of the following components in the feed and speed gears:
    1. Feed Gears
    2. Feed Change Gear
    3. Feed Gear Arm
    4. Feed Change Gear Bushing
    5. Spindle Speed Gears
    6. Thread Spindle Change Gears
  2. Identify the correct feed gears from the setup documentation.
  3. Identify the correct spindle speed gears from setup documentation.
  4. Remove gear case cover and remove the feed gears.
  5. Replace the feed gears and replace cover.
  6. Remove cover and remove the spindle speed gears.
  7. Replace the spindle speed gears and replace cover.

Lesson 5: Cross Slides, Cams, and Cutoff [ Top ]

After completing this lesson the operator will be able to:

  1. Identify and explain the purpose for each of the following:
    1. Form tools
    2. Cross slide form tool holder
    3. Positive Stop Screw
    4. Cross Slide Cam
    5. Cam Carrier
    6. Cam identification numbers
    7. The Rise of a Cam
    8. The Approach of a Cam
    9. The Feed of a Cam
    10. The Dwell of a Cam
    11. The Return of a Cam
    12. Sliding Block
    13. Cutoff Tool
  2. Explain the following:
    1. Control of cross slide travel
    2. Mounting sequence of Cam Carrier
    3. Positive Stop functions on a cross slide
    4. Cutoff positioning from spindle face
    5. Centering a tool to spindle centerline
  3. Remove cross slide cam carrier.
  4. Remove and replace cross slide cams on a carrier.
  5. From setup documentation, determine and set cross slide stroke.
  6. From setup documentation, clean, mount, position, and center a cutoff tool and tool holder.

Lesson 6: Restocking and Adjusting the Feed Length [ Top ]

After completing this lesson the operator will be able to:

  1. Explain the feed operation sequence.
  2. Disengage the Feed.
  3. Clean bar stock and remove burrs from bar ends.
  4. Check bar size against setup documentation.
  5. Load stock into stock tubes.
  6. Open collets and load bars.
  7. Start spindles and manually cutoff bar ends.
  8. Measure, calculate, and set a stationary stock stop.
  9. Measure, calculate, and set a movable stock stop.
  10. Install and set first position tool.

Lesson 7: Setting Basic Tooling [ Top ]

After completing this lesson the operator will be able to:

  1. Identify, locate, and explain the purpose of the following:
    1. Tool Setting Gauge
    2. Tool Holder Side Adjusting Screw
    3. First Position Gauge Surface
    4. Second Position Gauge Surface
    5. Third Position Gauge Surface
    6. Positive Stop Screw
    7. Tool Spindle Cam
    8. Tool Spindle Cam Roller
  2. Explain the purpose of properly setting Positive Stop tension.
  3. Based on setup documentation, correctly select the tools for the job.
  4. Clean, mount and center a form tool.
  5. Adjust the cross slide to position tool at low point and high point, and set depth of cut.
  6. Properly adjust positive stop tension for a cross slide.
  7. Install Tool Spindle cams.
  8. Set lever arms with block adjustment.
  9. Assemble end-working tool for tool spindle.
  10. Install end-working tool in tool spindle.
  11. Adjust the Tool Spindle to position tool at low point and high point, and set depth of cut.
  12. Jog through machining cycle.
  13. Measure and adjust features to size.

Lesson 8: Tooling and Part Troubleshooting [ Top ]

After completing this lesson the operator will be able to explain:

  1. Identify and explain the purpose for the basic tools and their holders used in the screw machine
    1. Screw Machine Drill
    2. Fast Spiral Drill
    3. Chip Breaker Drill
    4. Tapered Shank Drill
    5. Spot Drill
    6. Drill Holder
    7. Floating Holder
    8. Circular Form Tool
    9. Circular Form Tool Holder
  2. Given workpieces with and without chatter marks, be able to recognize those with chatter.
  3. Explain the 11 most common causes of chatter in the screw machine while using the Job Aid contained within the lesson.
  4. Explain how to correct the 11 most common causes of chatter in the screw machine while using the Job Aid contained within the lesson.
  5. Explain the 4 most common causes of short feed in the screw machine when only some of the parts produced are short.
  6. Explain the corrective action to use for each of the 4 common causes of short feed when only some of the parts produced are short.
  7. Explain the most common causes of short feed in the screw machine when all of the parts produced are short.
  8. Explain the corrective action to use for each of the common causes of short feed when all of the parts produced are short.
  9. Correctly identify a worn, damaged or dull drill.
  10. Measure and remove a drill.
  11. Correctly sharpen a drill, then measure cutting surfaces and drill-point angles.
  12. Correctly replace a drill to the previous depth of cut.
  13. Correctly identify a worn, damaged, or dull form tool.
  14. Remove a form tool.
  15. Correctly sharpen a form tool, and measure for squareness and proper rake and relief angles.
  16. Hone a newly sharpened form tool.
  17. Reinstall and center a form tool.
  18. Identify a damaged, worn or dull cutoff blade.
  19. Correctly measure and remove a cutoff blade.
  20. Correctly sharpen and measure rake and relief angles on a cutoff blade.
  21. Correctly replace a cutoff blade.

Lesson 9: The Sizing Attachment [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify, and explain a sizing attachment, it's operating sequence and component parts.
  2. Explain the size tool machining cycle.
  3. Clean and mount the size tool in the size tool holder.
  4. Preset the depth of the size cut to meet setup requirements.
  5. Clean the cross slide and mount the size tool attachment to the slide.
  6. Back off positive stop and the cross slide to eliminate contact at high point.
  7. Jog or hand crank the machine to high point.
  8. Align the size tool attachment to the formed workpiece and secure to the slide.
  9. Adjust attachment vertically until roller contacts workpiece, then secure.
  10. Adjust cross slide forward past centerline of part and secure cross slide.
  11. Identify and correct for taper.

Lesson 10: Tapping Operations [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify, and explain a tapping operating sequence and component parts.
  2. Check setup documents for correct threading cam.
  3. Engage threading gears to threading clutch.
  4. Align clutch shifting cam and connect operating mechanism.
  5. Install tap in holder.
  6. Set to thread under depth required.
  7. Adjust turnbuckle to achieve full thread.
  8. Tap workpiece and make final adjustments.

Lesson 11: Die Head Threading [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify, and explain a Die Head Threading attachment, it's operating sequence and component parts.
  2. Clean and mount the die head chasers if required, set size with sample part.
  3. Check for the correct threading gears and speed clutch operation based on right or left hand thread required.
  4. Place the tool spindle cam lever arc to the correct setting.
  5. Mount the yoke, yoke trip rod and die head.
  6. Jog machine to near end of thread.
  7. Set yoke to open die before end of thread.
  8. Jog to return and set jam nuts to close die head.
  9. Thread workpiece and adjust for correct thread length and depth, and die head closing.

Lesson 12: Thread Rolling [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify, and explain a thread rolling attachment, it's operating sequence and component parts.
  2. Check all thread roll components against setup documents.
  3. Clean and assemble thread rolls, and matched linkage arms to head.
  4. Mount the attachment to the machine.
  5. Attach connecting rods.
  6. Align attachment to the workpiece.
  7. Check position of rolls to centerline of part.
  8. Adjust for start of threading.
  9. Adjust turnbuckle slightly to increase thread depth.
  10. Run workpiece and adjust for full thread depth and dimension.
  11. Identify and correct for thread problems.

Lesson 13: The Pick-Off Attachment [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify, and explain a pick-off attachment, countersink arm, it's operating sequence and component parts.
  2. Mount bushings, pick-off slide, spindle and collet.
  3. Mount and connect back burring attachment and set pick-off collet tension.
  4. Mount and adjust knock out rod and back burring tool.
  5. Set collet closing and opening timing.
  6. Install pick-off collet assembly and set tension with sample workpiece.
  7. Set back burring tool for center.
  8. Install and set the cut-off tool.
  9. Jog through the cycle to cut-off and pick-off the workpiece.
  10. Run part and make final adjustments.

Lesson 14: The Box Tool [ Top ]

After completing this lesson the operator will be able to:

  1. Locate, identify, and explain a box tool attachment, it's operating sequence and component parts.
  2. Mount the Box Tool into the attachment, and center it.
  3. Adjust for depth of cut by setting roller position.
  4. Clean and mount the attachment to the correct tool spindle.
  5. Hand crank the box tool through a cycle to check for clearance.
  6. Feed out bar stock and perform a trial cut for depth with hand lever.
  7. Adjust to cut undersize.
  8. Adjust rollers to contact trial cut.
  9. Back tool off to cut to correct depth.
  10. Set length of cut.