Cnc Machinist

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Job Quizzes & Trivia

CNC MACHINIST KNOWLEDGE ASSESSMENT.


Questions and Answers
  • 1. 
    When referring to CNC programming, which of the following is the command coed to move the tool in the clockwise direction?
    • A. 

      G01

    • B. 

      G02

    • C. 

      G03

    • D. 

      G17

  • 2. 
    • A. 

      G90 G01 X_Y_R_F_;

    • B. 

      G17 G02 X_Y_R_F_;

    • C. 

      G90 G01 X_Y_Z_F_;

    • D. 

      G17 G03 X_Y_I_J_F_;

  • 3. 
    When referring to CNC programming, which of the following is the command coed to move the tool in the counter clockwise direction?
    • A. 

      G01

    • B. 

      G02

    • C. 

      G03

    • D. 

      G17

  • 4. 
    When referring to the elements of word address CNC programming, a "1" bit is a representation of an _________ condition.
    • A. 

      On

    • B. 

      Emergency

    • C. 

      Off

    • D. 

      Ultimate

  • 5. 
    Calculate the feed per minute when an 8 tooth CNC cutter is rotating at 700 rpm and the chip load is 0.008 inch. The feed per minute will be _______ inches.
    • A. 

      56.0

    • B. 

      44.8

    • C. 

      5.6

    • D. 

      0.7

  • 6. 
    Which of the following operations will produce a hole with 45 degree chamfers?
    • A. 

      Blind hole drilling.

    • B. 

      Spot drilling.

    • C. 

      Center drilling.

    • D. 

      Counter sinking.

  • 7. 
    The most common type of feed drives used on CNC machines is the:
    • A. 

      Electric servo motor.

    • B. 

      Hydraulic drive.

    • C. 

      Manual crank.

    • D. 

      Manual/hydraulic system.

  • 8. 
    When referring to CNC tapping operations, what does the acronym TDS stand for?
    • A. 

      Tap Drilling Speed

    • B. 

      Total Diameter Size

    • C. 

      Tap Drill Size

    • D. 

      Tap Down Speed

  • 9. 
    When referring to CNC operations, an excessive surface cutting speed will result in:
    • A. 

      Extended tool life.

    • B. 

      A longer time to machine the workpiece.

    • C. 

      Rapid tool wear.

    • D. 

      A decreased use of coolant.

  • 10. 
    When referring to common CNC programming structures, which of the following is the best example of an end of block character?
    • A. 

      ;

    • B. 

      G

    • C. 

      G00

    • D. 

      %

  • 11. 
    What is a major disadvantage of the vertical spindle machining centers?
    • A. 

      They can handle heavy workpieces.

    • B. 

      Chips accumulate on top of the workpiece.

    • C. 

      Some of the spindles have vertical motion.

    • D. 

      The crosslide can move transversally.

  • 12. 
    When referring to CNC programming, which of the following multiple hole patterns is typically the simplest to program?
    • A. 

      An arc hole pattern.

    • B. 

      A bolt hole circle.

    • C. 

      A linear hole pattern.

    • D. 

      An angular hole pattern.

  • 13. 
    The coolant system of a CNC machine would most commonly be a __________ pump.
    • A. 

      Low pressure

    • B. 

      Medium pressure

    • C. 

      High pressure

    • D. 

      Gravity

  • 14. 
    • A. 

      It is the program feed rate.

    • B. 

      It is the incremental dimensions from park location to cutting start and end points.

    • C. 

      It is the absolute dimensions of the cutting start and end points.

    • D. 

      It is the facing canned cycle command.

  • 15. 
    • A. 

      It is not possible to program tool nose radius compensation when using repetitive cycles G70-72.

    • B. 

      When programming TNR inside the cycle, you must cancel the compensation inside the cycle.

    • C. 

      It is not possible to program and cancel TNR outside the repetitive cycle

    • D. 

      For pattern repeating cycle G 73 the operator programs the number of rough cuts and the DOC workpiece.

  • 16. 
    • A. 

      The ratio of cut from the far to near surface.

    • B. 

      The depth of cut for the roughing pass.

    • C. 

      It is a block number immediately following the G71.

    • D. 

      It tells the CPU how the X value must be adjusted.

  • 17. 
    Which of the following CNC codes relates to "spindle on" counter clockwise at constant surface speed?
    • A. 

      N020 T0101

    • B. 

      N 030 G50 X8.500 Z7.500 S3000

    • C. 

      N040 M04 S500 G96

    • D. 

      N200 M05

  • 18. 
    With CNC programming it is good practice to program a rapid motion in ____ axis at a time.
    • A. 

      4

    • B. 

      3

    • C. 

      2

    • D. 

      1

  • 19. 
    When should a CNC linear interpolation command never be used?
    • A. 

      For programs longer than 27 lines

    • B. 

      Outside the work area.

    • C. 

      For canned programs

    • D. 

      With projects using 4 quarter addressing.

  • 20. 
    With CNC linear interpolation programming what does the U refer to in G01U__W__F__; (incremental feed motion)?
    • A. 

      The coordinate along the X axis.

    • B. 

      The coordinate along the Z axis.

    • C. 

      The program feed code.

    • D. 

      The linear interpolation code.

  • 21. 
    When applying tool measurement using a master reference tool and work shift, all Z values can be set to a pre-machined workpiece or the:
    • A. 

      Reference point of the machine.

    • B. 

      Face of the chuck.

    • C. 

      X0 point.

    • D. 

      Base of the tool turret.

  • 22. 
    Which of the following statement is true with respect to CNC multiple repetitive machining cycles?
    • A. 

      For boring or internal facing the tool must be located above the cored diameter.

    • B. 

      Only absolute values may be used for co-ordinate positions.

    • C. 

      The starting point should be as far away from the workpiece as possible to assist with tool movement.

    • D. 

      For external turning and facing the tool must be located above and in front of the workpiece.

  • 23. 
    Which of the following CNC codes deals with a multiple repetitive, rough cutting cycle used for facing operations?
    • A. 

      G94

    • B. 

      G76

    • C. 

      G72

    • D. 

      G68

  • 24. 
    • A. 

      The lead of the thread to four decimal places.

    • B. 

      The length of the thread including the deceleration distance.

    • C. 

      The minor diameter of the thread for external threads.

    • D. 

      The depth of cut for the threading pass.

  • 25. 
    With CNC repetitive cycle programming, what does the P stand for in the code G71P__Q__U__W__D__S__F__; (rough turning and boring repetitive cycle)
    • A. 

      The block number of the first tool motion from tool park location for machining the finish profile.

    • B. 

      The block number of the last tool motion completing the part profile and closing the repetitive cycle loop.

    • C. 

      The amount of material left on the diameter for the finish cut.

    • D. 

      The amount of material that is left on the Z faces for the finish cut.

  • 26. 
    Which of the following CNC codes cancels the mirror image coordinates for double turret turning centres?
    • A. 

      G94

    • B. 

      G76

    • C. 

      G72

    • D. 

      G69

  • 27. 
    How are CNC "G" codes grouped?
    • A. 

      According to their bit size.

    • B. 

      According to their function.

    • C. 

      Based on their sequence.

    • D. 

      Based on the number of significant digits.

  • 28. 
    When programming a multiple-start threading operation for a CNC machine, the shift amount is always equal to the ________ of the thread.
    • A. 

      Lead

    • B. 

      Depth

    • C. 

      Pitch

    • D. 

      Lag

  • 29. 
    • A. 

      The coordinate along the X axis.

    • B. 

      The coordinate along the Z axis.

    • C. 

      The program feed code.

    • D. 

      The linear interpolation code.

  • 30. 
    • A. 

      The block number.

    • B. 

      The type of offset.

    • C. 

      The value of the tool nose radius.

    • D. 

      The tool orientation number.

  • 31. 
    • A. 

      A code that allows the tool to dwell at a location.

    • B. 

      It instructs the control to move rapidly to specific X and Z locations.

    • C. 

      It is a linear interpolation feed rate code.

    • D. 

      It directs the machine control to use to use workpeice coordinate values stored in memory.

  • 32. 
    • A. 

      The diameter of the bit.

    • B. 

      The major diameter of the thread being cut.

    • C. 

      The outside diameter of the headstock.

    • D. 

      The inside major diameter of the thread being reamed.

  • 33. 
    • A. 

      It is used where work must be machined on both ends.

    • B. 

      It is designed for work that must be machined from both sides at the same time.

    • C. 

      It is the most common arrangement.

    • D. 

      It is used in high production machining.

  • 34. 
    When using the right hand rule for identifying an axis, what does the index finger represent?
    • A. 

      The Z axis.

    • B. 

      The Y axis.

    • C. 

      The X axis.

  • 35. 
    • A. 

      Transitional

    • B. 

      Positional

    • C. 

      Modulated

    • D. 

      Direct

  • 36. 
    What angle of bed decline do most CNC turning machines have to assist with chip management?
    • A. 

      70-85

    • B. 

      50-65

    • C. 

      30-45

    • D. 

      18-28

  • 37. 
    In which of the following CNC program preparation systems is the program prepared off line then stored on a disc or hard drive ?
    • A. 

      Text editor.

    • B. 

      MDI.

    • C. 

      CAM software.

    • D. 

      MMI configuration.

  • 38. 
    With CNC turning machines, the programmed speed for tapping is generally 25 to ____ % of that used for drilling.
    • A. 

      50

    • B. 

      46

    • C. 

      33

    • D. 

      27

  • 39. 
    Which of the following is true with respect to a Preparatory (G) code?
    • A. 

      They turn various functions of the machine on or off.

    • B. 

      They are modal or non modal.

    • C. 

      They follow EIA/ASC11 guidelines.

    • D. 

      It controls directly tool, speed and feedrate functions.

  • 40. 
    What principle of measurement does a rotary encoder use?
    • A. 

      Transitional

    • B. 

      Positional

    • C. 

      Indirect

    • D. 

      Direct

  • 41. 
    • A. 

      It is used for comments and messages in front of the program.

    • B. 

      It is used to skip program blocks.

    • C. 

      It is used to indicate program number for ISO standard.

    • D. 

      It is used at the end of each program block.

  • 42. 
    With CNC turning machines and Miscellaneous (M ) codes what does a "M03" represent?
    • A. 

      Program stop and ends program execution.

    • B. 

      Optional stop used when occasional part inspection may be required.

    • C. 

      Spindle on in clockwise rotation.

    • D. 

      Spindle on in counter clockwise rotation.

  • 43. 
    • A. 

      The tape has to be fast forwarded or reversed to locate the required program.

    • B. 

      It is historically the only medium for program storage and transfer

    • C. 

      They can be used for storage large amounts of program data in a compressed form.

    • D. 

      They can be affected by viruses but have the largest storage capacity.

  • 44. 
    What is the common rotary resolution for most CNC machines in degrees?
    • A. 

      0.0001

    • B. 

      0.001

    • C. 

      0.01

    • D. 

      0.1

  • 45. 
    • A. 

      RAM connecting directly to binary logic allowing machining logic.

    • B. 

      It is a type of ROM that allows a programmed feedback loop.

    • C. 

      Its function is to develop signals from program data for driving servo motors.

    • D. 

      It allows a CNC machine to be programmed.

  • 46. 
    When using the right hand rule for identifying an axis, what does the middle finger represent?
    • A. 

      The Z axis.

    • B. 

      The Y axis.

    • C. 

      The X axis.

  • 47. 
    • A. 

      The tape has to be fast forwarded or reversed to locate the required program.

    • B. 

      It is historically the only medium for program storage and transfer

    • C. 

      They can be used for storage large amounts of program data in a compressed form.

    • D. 

      They can be affected by viruses but have the largest storage capacity.

  • 48. 
    • A. 

      The position of the tool clear of the work piece after the profile is machined.

    • B. 

      The last location on the work piece defining the profile to be machined.

    • C. 

      The first location chew off the work piece before defining the part profile to be machined

    • D. 

      The XZ position of the tool before the repetitive cycle G71 is activated.

  • 49. 
    • A. 

      It allows dimensions to be written without the zeros in front of the decimal point.

    • B. 

      It is used to reduce the number of zeros in the full format dimensions.

    • C. 

      It allows dimensions to be written without the zeros after the decimal point

    • D. 

      Where eight digits are required for each dimension.

  • 50. 
    • A. 

      Each program character is represented in rows containing odd number holes.

    • B. 

      The number of wires from the controller to the hardware is always odd.

    • C. 

      The RAM is sectored off in odd divisions.

    • D. 

      The hard drive is mathematically tuned to mathematical operations thst result in odd numbers.