1. SUBMITTED BY: PIYUSH NAYAK NC CODE AND TOOL PATH GENERATION USING NX CAM 2. CONTENTS Introduction NX 5 NC CODE Operations window About model Generation of program Tool path display Simulation and verification of tool path References 3. INTRODUCTION Implementing a designed model of die cavity into manufacturing environment for machining in the NX 5 software. Generation, verification and simulation of tool path to produce CNC (computer numerical code) 4. NX 5 NX is cad/cam/cae software developed by siemens PLM Software NX was originally called unigraphics which was developed by united computing in 1977 NX is parametric, solid, feature based modeling system NX is widely used in the engineering industry, especially in the automotive and aerospace sectors 5. NC CODE Numerical control can be defined as a form of programmable automation in which the process is controlled by numbers, letters and symbols. It has a wide application in metal cutting machine tools, drilling and boring. 6. FUNCTION CODES: Preparatory Function Word: (G) These are the commands which prepare the machine for different modes of movement like positioning, contouring, thread cutting etc. They always precedes the dimension word. Feed Word: (F) The F is used in contouring and straight cut systems. In point to point straight cut systems a constant maximum feed rate is used to move the tool from point to point. Feed is usually programmed in mm/rev or mm/min. Spindle Speed Word: (S) The spindle speed can be specified in RPM, whereas, the cutting speed is specified in m/min. The speed word allows for both the cases. For example a speed of 500rpm. Is programmed G97 as S500 directly. As the cutting parameters specified is cutting speed, a more convenient method of programming is to specify the cutting speed and this can be directly programmed using G96. Tool Word: (T) Tool word may be coded using 1,2,3, or 4 digits. Each cutting tool or tool position in the tool magazine has a code number. The tool specified is selected by the automatic tool changes when the code number is programmed in a block. Miscellaneous Function: (M) This function pertains to auxiliary or switching information which does not relate to dimensional movement of the machine, such as spindle command, or coolant ON/OFF etc. 7. Survey of G Commands (ISO Codes) Command Function Command Function A A G 00 Rapid traverse G 54 Zero offset 1 G 01 Linear interpolation G 55 Zero offset 2 G 02 Circular interpolation clockwise G 56 Zero offset 3 G 03 Circular interpolation counter clockwise G 57 Zero offset 4 G 04 Dwell G 58 Programmable Zero offset 1 G 09 Exact stop blockwise G 59 Programmable Zero offset 2 G 17 Plane selection XY G 60 Zero offset 5 G 18 Plane selection ZX G 61 Zero offset 6 G 19 Plane selection YZ G 62 Zero offset 7 G 40 Cancel cutter radius compensation G 63 Zero offset 8 G 41 Cutter radius compensation left G 64 Programmable Zero offset 3 G 42 Cutter radius compensation right G 65 Programmable Zero offset 4 G 50 Cancel scale modification G 66 Zero offset 9 G 51 Scale modification G 67 Zero offset 5 G 53 Cancel zero offset blockwise G 68 Zero offset 6 G 69 Zero offset 7 8. Survey of M- Codes Command Meaning M00 Programmed stop, unconditional M01 Programmed stop, conditional M02 Main program end M03 Spindle ON clockwise M04 Spindle ON counter clockwise M05 Spindle OFF M06 Tool exchange M08 Coolant ON M09 Coolant OFF M17 Subroutine end M25 Release Clamping device M26 Grip Clamping device M30 Main program end M50 Direction logic tool turret OFF M53 No mirror axis X M54 Mirror axis X M55 No mirror axis Y M56 Mirror axis Y M57 No mirror axis Z M58 Mirror axis Z 9. Cutting Parameters: Cutting Speed (V): relative velocity of the tool with respect to the work surface. (Surface feet per minute (sfpm), m/min) Calculation of cutting speed The manufacturers catalogs or table book is used to initially determine the optimum cutting speed. By calculation D [ mm] * * S [rpm] V [m/min] = ------------------------------------- 1000 V [m/min] cutting speed D [mm] diameter of work piece S [rpm] ...speed of main spindle Rotational (Spindle) Speed (S): Speed of cutting tools that rotate (rev/min). Feed (f): Lateral displacement of the cutting tool relative to the work on each pass or revolution of the tool (in./rev, in./pass). Feed rate is the tool movement (traverse) in the machining direction. The feed rate is obtained by the programmer from the table book of the tool manufactures manuals and from the experienced gained by the programmer. The unit of feed is mm per revolution of the work piece or mm per minutes. In CNC programs the feed rate generally carries the code Letter F. Depth of cut: The distance the tool penetrates below the original surface of the work (in., mm). 10. Model of die cavity 11. BLANK 12. MANUFACTURING Select START MANUFACTURING 13. For CAM Session Configuration, select cam_general and for CAM Setup, select mill_contour. This window pops up when you start the Manufacturing Application 14. CREATING OPERATION AND PARAMETER SETTING Click on the Create Operation icon in the toolbar as shown Type of Operation is mill_contour Click on the CAVITY_MILL icon at the top left as shown in the figure. Change the Program from NC_PROGRAM to program. Change the Use Geometry to WORKPIECE Click OK. 15. On the new tool window select the mill icon Type in BUEM12X1 as the Name and click OK Enter the values as shown in the figure below. 16. Milling tools parameter 17. Tool Path Settings select the Follow Part icon from the Cut Pattern. For the Step-over, select TOOL DIAMETER and change the Percent to 70. 18. Depth per cut Change the Global Depth per Cut value to be 0.5. Click on CUT LEVELS as shown below. 19. Cut Level Use the up and down scroll buttons until you reach the level that has a Range Depth of 80. Select measured from top level. Select OK after making these adjustments. 20. Under the Strategy tab button, change the Cut Order from Level First to DEPTH FIRST. 21. CUTTING PARAMETER 22. NON CUTTING MOVES Click the AVOIDANCE tab. Click FROM POINT. Choose SPECIFY. In the Point Constructor, enter the coordinates of XC, YC and ZC as (0, 0, 50). Choose OK. 23. Click on the TRANSFER/RAPID tab. Choose PLANE in the CLEARANCE OPTION. SELECT plane. 24. Enter the Offset value as 3 in the Plane constructor window. Click on the XY Plane icon toward the bottom of the window. Click OK twice to go back to the parameters window. 25. Speed Speed normally specifies the rpm of the spindle speed. Enter the Spindle Speed value as 4500 rpm. 26. Feeds Enter the cut value 1200 in mmpm Click OK. 27. Program Generation And Verification Click on the Generate icon at the bottom of the window. 28. GENERATED TOOL PATH 29. Tool Path Simulation 30. You can also view the visualization in different modes Click on the 3D DYNAMIC tab on the same window. Change the Number of Motions to 50. Change the Animation Accuracy to FINE. Change the IPW Color to Green. Click OK. Click on the Play button again. 31. The simulation will look as shown in the figure below:- 32. SIMULATION VIDEO 33. REFERENCES CAD/CAM by Mikell P. Groover Publisher:-Pearson Education Reprint 2009 Websites:- www.siemens.com 34. THANKS