CNC Lathe Coordinates PDF

MACHINIST PROGRAM - FIRST PERIOD MACHINE CO-ORDINATE SYSTEMS FOR CNC TURNING MACHINES 150102j  MODULE OBJECTIVES 1. Describe the Coordinate points of a workpiece using absolute and Incremental values 2. Describe the CNC axis System 3. Describe the purpose for reference points used on a...

MACHINIST PROGRAM - FIRST PERIOD MACHINE CO-ORDINATE SYSTEMS FOR CNC TURNING MACHINES 150102j  MODULE OBJECTIVES 1. Describe the Coordinate points of a workpiece using absolute and Incremental values 2. Describe the CNC axis System 3. Describe the purpose for reference points used on a CNC Turning Centre. CARTESIAN PLANE X,Y CO-ORDINATE (CARTESIAN) PLANE: CO-ORDINATE (CARTESIAN) PLANE: Y-AXIS ORIGIN (X0,Y0) X-AXIS CO-ORDINATE (CARTESIAN) PLANE: QUADRANTS CO-ORDINATE (CARTESIAN) PLANE: (-,+) (+,+) (-,-) (+,-) (x,y) FORMAT FOR MILLING MACHINES CO-ORDINATE (CARTESIAN) PLANE: (x,y) FORMAT FOR MILLING MACHINES CO-ORDINATE (CARTESIAN) PLANE: X Y Point 1 2 Point 2 1 Point 3 Point 4 3 4 (x,y) FORMAT FOR MILLING MACHINES CO-ORDINATE (CARTESIAN) PLANE: X Y Point 1 3.0 1.0 2 Point 2 -4.0 3.0 1 Point 3 -3.0 -4.0 Point 4 5.0 -5.0 3 4 (x,y) FORMAT FOR MILLING MACHINES CO-ORDINATE (CARTESIAN) PLANE: Y+ X+ X- Y- CARTESIAN PLANE X,Z CO-ORDINATE (CARTESIAN) PLANE: FOR LATHES CO-ORDINATE (CARTESIAN) PLANE: X-AXIS (DIAMETER) Z-AXIS FOR LATHES CO-ORDINATE (CARTESIAN) PLANE: X-AXIS (DIAMETER) (+,-) (+,+) Z-AXIS (-,-) (-,+) (x ,z) dia FORMAT FOR LATHES CO-ORDINATE (CARTESIAN) PLANE: X-AXIS (DIAMETER) Z-AXIS (x ,z) dia FORMAT FOR LATHES CO-ORDINATE (CARTESIAN) PLANE: X-AXIS (DIAMETER) Z-AXIS (x ,z) dia FORMAT FOR LATHES CO-ORDINATE (CARTESIAN) PLANE: X-AXIS (DIAMETER) 2 1 X Z Point 1 Z-AXIS Point 2 (x ,z) dia FORMAT FOR LATHES CO-ORDINATE (CARTESIAN) PLANE: X-AXIS (DIAMETER) 2 1 X Z Point 1 6.0 0.0 Z-AXIS Point 2 6.0 -5.0 (x ,z) dia FORMAT FOR LATHES CO-ORDINATE (CARTESIAN) PLANE: SL – PRODUCTION CNC LATHE (SLANT BED) TL – HYBRID CNC LATHE (FLAT BED) X+ Z- Z- Z+ Z+ X- X+ X-  WORKPIECE CO-ORDINATE POINTS ABSOLUTE AND INCREMENTAL  ABSOLUTE POSITIONING ABSOLUTE POSITIONING: ALL CO-ORDINATES ARE SPECIFIED IN RELATION TO THE PROGRAM ZERO POINT. G90 CODE IS USED TO INITIATE ABSOLUTE POSITIONING. X AND Z: USED TO SPECIFY A SPECIFIC LOCATION IN RELATION TO THE ZERO POINT. PROGRAM ZERO POINT (ABSOLUTE): FRONT OF WORKPIECE THE PROGRAM ZERO CAN BE PLACED AT EITHER END OF THE WORKPIECE. IN THIS EXAMPLE IT IS PLACED ON THE RIGHT- HAND SIDE. (FRONT) PROGRAM ZERO POINT (ABSOLUTE): BACK OF WORKPIECE THE PROGRAM ZERO CAN BE PLACED AT EITHER END OF THE WORKPIECE. IN THIS EXAMPLE IT IS PLACED ON THE LEFT- HAND SIDE. (BACK) INCREMENTAL POSITIONING INCREMENTAL POSITIONING: EACH NEW CO-ORDINATE IS BASED ON THE PREVIOUS CO- ORDINATE OF THE TOOL. (WHERE THE TOOL CURRENTLY IS LOCATED) THERE IS NO REFERENCE TO THE PROGRAM ZERO POINT. U(x) AND W(z): USED TO SPECIFY A SPECIFIC LOCATION IN RELATION TO THE PREVIOUS POINT. (U is given as a diameter) G91 CODE IS USED TO INITIATE INCREMENTAL POSITIONING. PROGRAM ZERO POINT (INCREMENTAL): FRONT OF WORKPIECE THE FIRST POINT IS BASED ON THE ORIGIN (PROGRAM ZERO). FROM THERE, EACH POINT IS BASED ON THE PREVIOUS POINT. THE SIGN INDICATES THE DIRECTION (POLARITY) OF THE MOVEMENT, AND THE VALUE INDICATES THE DISTANCE OF THE MOVEMENT.  MACHINE ZERO (HOME POSITION) (ZERO RETURN)  MACHINE ZERO POSITION (HOME): THE MACHINE HAS NO WAY OF KNOWING WHERE IT IS WHEN IT IS POWERED UP. MOST MACHINE BUILDERS HAVE A BUTTON ON THE CONTROL PANEL THAT INITIATES A SEQUENCE WHERE THE AXES ARE MOVED UNTIL THEY REACH THE MACHINE LIMITS, AND THEN THE POSITION IS REGISTERED. ALL TOOL AND WORK POSITIONS ARE BASED OFF OF THE HOME POSITION. TOOL NOSE RADIUS AND TOOL SETTING THE EFFECTS OF TOOL NOSE RADIUS (TNR): THE PROGRAMMED POINT OF A SINGLE POINT CUTTING TOOL. THE TOOL NOSE RADIUS MUST BE TAKEN INTO ACCOUNT WHEN FACING OR CUTTING A RADIUS OR TAPER. THE EFFECTS OF TOOL NOSE RADIUS (TNR): A TOOL WITH A 0.031” NOSE RADIUS MUST EXTEND PAST THE CENTERLINE BY DOUBLE THE NOSE RADIUS … IN THIS CASE: -0.062” (NEGATIVE BECAUSE THE TOOL IS NOW ON THE OPPOSITE SIDE THE PROGRAM CODE WOULD LOOK LIKE THIS: OF THE PART CENTER) N015 G01 X-0.062 COMMON CUTTING TOOL STYLES: EACH TYPE OF TOOL IS TOUCHED OFF DIFFERENTLY FROM THE NEXT TYPE. THE CNC MACHINES NEED TO KNOW HOW EACH TOOL DIFFERS FROM ONE ANOTHER BEFORE IT CAN BE RUN. TOUCHING OFF THE TOOLS: EACH TYPE OF TOOL MUST BE TOUCHED OFF ON THE DIAMETER AS WELL AS ON THE LENGTH. THE MODULE STATES IN REALITY, THE TOOLS THAT TOOLS CAN BE ARE NORMALLY SET TO TOUCHED OFF ON THE THE FRONT FACE OF FACE OF THE CHUCK, THE MATERIAL … AFTER SINCE IT NEVER A FACING PASS HAS CHANGES POSITION. BEEN TAKEN. (A SHIFT VALUE WOULD NEED TO BE ENTERED IN SO THAT THE FACE OF THE PART AND NOT THE CHUCK WOULD BE SET) CNC LATHES WITH ADDITIONAL AXES (MULTI-AXIS) 3-AXIS MACHINES: X-AXIS Z-AXIS C-AXIS 3-AXIS MILL/TURN CNC ( X,Z,C AXIS) VIDEO: 3-AXIS CNC LATHE (X,Z,C) 4-AXIS MACHINES: X-AXIS Z-AXIS C-AXIS Y-AXIS 4-AXIS MILL/TURN CNC ( X,Z,C,Y AXIS) VIDEO: 4-AXIS CNC LATHE (X,Z,C,Y) SUB-SPINDLE MACHINES: SUB-SPINDLE MACHINES VIDEO: SUB-SPINDLE LATHE END