IME 146 CNC Final Exam Questions with Verified Answers

IME 146 CNC Final Exam Questions with Verified Answers Three different components of CNC machines 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? manual programing, conversational programming, CAD/CAM programing. What type of coordinate system is CNC milling G & M code based off of? 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? 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? 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? 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? 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. 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). G02, Clockwise G03 (Counter-clockwise) cuts and arc or circle. G01 cuts in a straight line G03 What is an M code? An M code are miscellaneous codes. Give two examples of commonly used M codes in a CNC program. M06 (tool change), and M30 (End program) 21⁄2-axis CNC toolpaths only the X and Y axes move simultaneously 3-axis CNC toolpaths? 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? makes the code for the appropriate machine tool brand. What type of polymers are utilized in the injection molding manufacturing process? thermoplastics