IME 146 FINAL EXAM | QUESTIONS AND ANSWERS | WITH COMPLETE SOLUTION
Three different components of CNC machines - (ANSWER)1. Program of Instructions (G&M Codes)
2. Machine Control Unit (controller)
3. Processing Equipment (tooling)
What are the three main ways G & M code can be created for a CNC machine? - (ANSWER)manual
programing, conversational programming, CAD/CAM programing.
What type of coordinate system is CNC milling G & M code based off of? - (ANSWER)Cartesian
coordinate system.
Our Haas CNC machines have a closed loop positioning system. What does this mean, and how does the
closed loop system work? - (ANSWER)closed loop system get feedback to verify that the appropriate
actions have occurred. In the closed loop system a machine control sends a motion signal through a
controller board to a servomotor. This servomotor rotates causing the table to move in an opposite
direction. Then an optical encoder continuously compares and monitors the position of the axis to the
commanded position.
What is the purpose of the ball screw in a CNC mill's drive system? - (ANSWER)turns rotary motion from
the servo motor into linear axis motion.
What is a fixture offset (WCS) used for in a CNC mill and what is the most common alphanumeric code
used to call up a fixture offset in a CNC program? - (ANSWER)used to provide a way for the CNC control
to know the distance from the machine home position and parts coordinate system. G54 "home
location" is the most common alphanumeric code used to call up a fixture offset in a CNC program.
What is the purpose of a tool length offset in a CNC mill? What alphanumeric codes are used to set a
tool length offset in a CNC program? - (ANSWER)The stick out then tells us the relative position of the
bottom of the tool to the WCS. G43 is the code used to set a tool length offset in a CNC program.
What is a G-code? Give two examples of commonly used G codes in a CNC program. -
(ANSWER)preparatory codes that prepare the machine for a certain type of motion. Commonly used G
codes in a CNC program would include, G00 (rapid motion), and G54 (Home locations).
, IME 146 FINAL EXAM | QUESTIONS AND ANSWERS | WITH COMPLETE SOLUTION
G02, - (ANSWER)Clockwise
G03 - (ANSWER)(Counter-clockwise) cuts and arc or circle.
G01 - (ANSWER)cuts in a straight line G03
What is an M code? - (ANSWER)An M code are miscellaneous codes.
Give two examples of commonly used M codes in a CNC program. - (ANSWER)M06 (tool change), and
M30 (End program)
2½-axis CNC toolpaths - (ANSWER)only the X and Y axes move simultaneously
3-axis CNC toolpaths? - (ANSWER)XY&Z axes move simultaneously to generate the surface profile.
purpose of the post processor in when using CAD/CAM software to program a CNC machine? -
(ANSWER)makes the code for the appropriate machine tool brand.
What type of polymers are utilized in the injection molding manufacturing process? -
(ANSWER)thermoplastics
What are the function of the runners in an injection mold? - (ANSWER)allows the plastic to flow from
the nozzle to the cavity.
What is the definition of a short shot in injection molding? - (ANSWER)molten plastic does not fill the
mold cavity completely.
What is one of the primary causes of a short shot? - (ANSWER)having too little pressure.
Three different components of CNC machines - (ANSWER)1. Program of Instructions (G&M Codes)
2. Machine Control Unit (controller)
3. Processing Equipment (tooling)
What are the three main ways G & M code can be created for a CNC machine? - (ANSWER)manual
programing, conversational programming, CAD/CAM programing.
What type of coordinate system is CNC milling G & M code based off of? - (ANSWER)Cartesian
coordinate system.
Our Haas CNC machines have a closed loop positioning system. What does this mean, and how does the
closed loop system work? - (ANSWER)closed loop system get feedback to verify that the appropriate
actions have occurred. In the closed loop system a machine control sends a motion signal through a
controller board to a servomotor. This servomotor rotates causing the table to move in an opposite
direction. Then an optical encoder continuously compares and monitors the position of the axis to the
commanded position.
What is the purpose of the ball screw in a CNC mill's drive system? - (ANSWER)turns rotary motion from
the servo motor into linear axis motion.
What is a fixture offset (WCS) used for in a CNC mill and what is the most common alphanumeric code
used to call up a fixture offset in a CNC program? - (ANSWER)used to provide a way for the CNC control
to know the distance from the machine home position and parts coordinate system. G54 "home
location" is the most common alphanumeric code used to call up a fixture offset in a CNC program.
What is the purpose of a tool length offset in a CNC mill? What alphanumeric codes are used to set a
tool length offset in a CNC program? - (ANSWER)The stick out then tells us the relative position of the
bottom of the tool to the WCS. G43 is the code used to set a tool length offset in a CNC program.
What is a G-code? Give two examples of commonly used G codes in a CNC program. -
(ANSWER)preparatory codes that prepare the machine for a certain type of motion. Commonly used G
codes in a CNC program would include, G00 (rapid motion), and G54 (Home locations).
, IME 146 FINAL EXAM | QUESTIONS AND ANSWERS | WITH COMPLETE SOLUTION
G02, - (ANSWER)Clockwise
G03 - (ANSWER)(Counter-clockwise) cuts and arc or circle.
G01 - (ANSWER)cuts in a straight line G03
What is an M code? - (ANSWER)An M code are miscellaneous codes.
Give two examples of commonly used M codes in a CNC program. - (ANSWER)M06 (tool change), and
M30 (End program)
2½-axis CNC toolpaths - (ANSWER)only the X and Y axes move simultaneously
3-axis CNC toolpaths? - (ANSWER)XY&Z axes move simultaneously to generate the surface profile.
purpose of the post processor in when using CAD/CAM software to program a CNC machine? -
(ANSWER)makes the code for the appropriate machine tool brand.
What type of polymers are utilized in the injection molding manufacturing process? -
(ANSWER)thermoplastics
What are the function of the runners in an injection mold? - (ANSWER)allows the plastic to flow from
the nozzle to the cavity.
What is the definition of a short shot in injection molding? - (ANSWER)molten plastic does not fill the
mold cavity completely.
What is one of the primary causes of a short shot? - (ANSWER)having too little pressure.
