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CNC Tutorials and Exercises Boxford DUET CNC Tutorials and Exercises CNC Tutorials and ExercisesBoxford DUET This tutorial gives examples of absolute co-ordinates and incremental co-ordinates. Absolute Co-ordinates The code G90 is used to select this type of programming. Before programming commences the points on the path to be machined are defined relative to the workpiece datum: Examples of these co-ordinates are shown in the first table on the next page. Tutorial 1: X and Y Co-ordinate Calculation - Absolute and Incremental Co-ordinates Y+ B C D E F A -1 Y- X+ X- -2-3-4-5-6-7-8-9-10 1 2 3 4 5 6 7 8 9 10 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 1 2 3 4 5 6 7 8 9 10 G H ORIGIN X0 Y0 Tutorial 1 CNC Tutorials and Exercises Boxford DUET POINT DATUM A B C D E F G H X 0 5 5 -14 -5 2 3 11 -2 Y 0 4102-10-313 The Z axis is the vertical axis and the datum used is normally the surface of the work. Z is positive when moving away from the surface and negative when moving towards or into the surface. POINT DATUM A B C D E F G H X0510-4-9-7-475 Y 0 4 5 5 7 -3 -6 -5 -2 Incremental Co-ordinates The code G91 is used to select this type of programming. The points on the path to be machined are defined relative to the previous position. The points for the example on the previous page are shown in the table below. The Z axis is again the vertical axis, and the points are defined relative to the previous position; positive when moving away from the surface and negative when moving towards or into the surface. Tutorial 1 CNC Tutorials and ExercisesBoxford DUET Exercise 1 : Calculation of Co-ordinates Tabulate the positions of the points A to H shown in the illustration below: a) in absolute co-ordinates b) in incremental co-ordinates B C D E F A -1-2-3-4-5-6-7-8 -1 -2 -3 -4 -5 -6 1 2 3 4 5 6 G H 1 2 3 4 5 6 7 8 Y+ Y- X+ X- Tutorial 1 CNC Tutorials and Exercises Boxford DUET This tutorial illustrates the use of the G01 code; cutting takes place in a straight line at a controlled feed rate. Consider the component illustrated below; it is required to mill the two L shaped slots. Absolute Co-ordinates The absolute co-ordinates of the points are shown in the table below: X Y 45 15 20 30 80 50 15 20 BCD EFA Material: Grooves: Tool change at: Tool used: 15mm thick Plastic 5 wide x 2 deep X 0, Y 0, Z 25 5mm Slot Drill Tutorial 2: Linear Interpolation POINT A B C D E F T.C. X 1515 45656535 0 Y 1535 35351515 0 The program can be written in tabulated format as shown on the following page. Note: G00 is a default value and need not be programmed. The first tool is selected when entering the program into the computer. Tutorial 2 CNC Tutorials and ExercisesBoxford DUET ABSOLUTE PROGRAMMING N10 90 METRIC UNITS N20 71 TOOL CHANGE N30 0 0 25 SPINDLE N40 03 1500 2mm ABOVE POINT A N50 15 15 2 FEED TO 2 DEEP N60 01 –2 125 POINT B N70 01 15 35 125 POINT C N80 01 45 125 2mm ABOVE WORK N90 2 ABOVE POINT D N100 65 FEED TO 5 DEEP N110 01 –2 125 POINT E N120 01 15 125 POINT F N130 01 35 125 2mm ABOVE WORK N140 2 PARK POSITION N150 05 0 0 25 END OF PROGRAM N160 30 TUT 2/1 1 1 Tutorial 2 DUET PROGRAMMING SHEET-MILLING DRAWING NUMBER TITLE PROGRAMMED BY SHEET No. OF SEQUENCE No. PREP FUNCTION MISC FUNCTION CO-ORDINATES FEED RATE SPINDLE SPEED NGM Y ZJFS NOTES X I CNC Tutorials and Exercises Boxford DUET N10 G90 N20 G71 N30 X0 Y0 Z25 N40 M03 S1500 N50 X15 Y15 Z2 N60 G01 Z-2 F125 N70 G01 X15 Y35 F125 N80 G01 X45 F125 N90 Z2 N100 X65 N110 G01 Z-2 F125 N120 G01 Y15 F125 N130 G01 X35 F125 N140 Z2 N150 M05 X0 Y0 Z25 N160 M30 Incremental Co-ordinates The incremental co-ordinates for the component are shown in the table below. Using these co-ordinates the program can be written as shown as follows: POINT TOOL A B C D E F T.C. FROM CHANGE F X 0 35 0 30 20 0 -30 -35 Y 0 35 20 0 0 -20 0 -15 Using compact format, the program for the component shown previously will be as follows: Tutorial 2 CNC Tutorials and ExercisesBoxford DUET DUET PROGRAMMING SHEET-MILLING DRAWING NUMBER TITLE PROGRAMMED BY SHEET No. OF SEQUENCE No. PREP FUNCTION MISC FUNCTION CO-ORDINATES FEED RATE SPINDLE SPEED NGM Y ZJFS NOTES X I Tutorial 2 1. Examine the program listed 2. Enter the program into the computer 3. Simulate the machining process and compare the movement of the cutter with the program ABSOLUTE PROGRAMMING N10 90 METRIC UNITS N20 71 TOOL CHANGE N30 0 0 25 INCREMENTAL PROGRAMMING N40 91 SPINDLE START RAPID TO 2mm ABOVE A N50 03 15 15 –23 1500 FEED TO mm DEPTH N60 01 –4 125 FEED FROM A TO B N70 01 0 20 125 FEED FROM B TO C N80 01 30 0 125 RAPID TO CLEARANCE PLANE N90 4 RAPID TO 2mm ABOVE D N100 20 0 FEED TO 2mm DEPTH N110 01 –4 125 FEED FROM D TO E N120 01 0 –20 125 FEED FROM E TO F N130 01 –30 0 125 RAPID TO CLEARANCE PLANE N140 4 STOP SPINDLE RAPID TO PARK POSITION N150 05 –35 –15 23 END OF PROGRAM N160 30 TUT 2/2 1 1 Using these co-ordinates the program can be written as shown as follows: CNC Tutorials and Exercises Boxford DUET POINT TOOL CHANGE A B C D E F G H X 0 20 60 20 20 60 20 60 60 Y 0 10 10 30 20 40 40 20 30 1. For the component shown below, use a programming sheet and write a program for the cutter to cut a groove along the path from A to H. 2. Enter your program into the computer and give it a test run. 3. Edit your program if necessary. Absolute Co-ordinates X Y 80 50 B C D E F A Material: Slots: Tool change at: Tool used: 15mm thick Plastic 5 wide x 2 deep X 0, Y 0, Z 25 5mm Slot Drill H G Exercise 2: Linear Interpolation - Absolute Co-ordinates Tutorial 2 CNC Tutorials and ExercisesBoxford DUET Tutorial 3 POINT A B C D X20206060 Y15353515 Canned cycles are used to shorten and simplify the CNC program. This tutorial gives examples of the G81 Hole Drilling and G88 Pocket Milling cycles. G81 Hole Drilling This code drills a hole at the current X and Y values to a depth of Z measured incrementally from the face of the workpiece and then withdraws to the previous Z value i.e. 2mm clear. Enter Z incremental distance from the face of the workpiece to the bottom of the hole) F (feed rate) 20 40 80 50 15 20 BC D A Tool change at: Tool used: X -5, Y -5 5mm Slot Drill 4 x Ø 5 holes 10 deep Tutorial 3: Canned Cycles - Hole Drilling and Pocket Milling . CNC Tutorials and Exercises Boxford DUET CNC Tutorials and Exercises CNC Tutorials and ExercisesBoxford DUET This tutorial. Tutorial 2 CNC Tutorials and ExercisesBoxford DUET Tutorial 3 POINT A B C D X20206060 Y15353515 Canned cycles are used to shorten and simplify the CNC program.