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Cnc programming
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- 2. Types of AutomationManufacturingAutomationHard/Rigid/ MechanizedAutomationSoft/ Flexible/ ProgrammableAutomationCopy milling machines AutomatsSpecial purpose machinesCNC Machines RobotsAutomatically Guided Vehicles (AGVs) Reconfigurable conveyors Unlimited muscle powerSpeedAccuracyUnmanned operationFlexibilitySimplified generic tooling even for the most complex jobsAdvantages of Soft Automation
- 3. Introduction to CNCConventionally,an operator decides and adjusts various machines parameters like feed , depth of cut etc depending on type of job , and controls the slide movements by hand. In a CNC Machine functions and slide movements are controlled by motors using computer programs. The most basic function of any CNC machine is automatic, precise, and consistent motion control.The two most common axis types are linear (driven along a straight path) and rotary (driven along a circular path).
- 4. Introduction to CNCConventionally,an operator decides and adjusts various machines parameters like feed , depth of cut etc depending on type of job , and controls the slide movements by hand. In a CNC Machine functions and slide movements are controlled by motors using computer programs. The most basic function of any CNC machine is automatic, precise, and consistent motion control.The two most common axis types are linear (driven along a straight path) and rotary (driven along a circular path).
- 5. Why CNC isAccurate?
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- 8. Important G CodesG00Rapid TransverseG01 Linear InterpolationG02 Circular Interpolation, CWG03 Circular Interpolation, CCWG17 XY Plane,G18 XZ Plane,G19 YZ PlaneG20/G70 Inch unitsG21/G71 Metric UnitsG40 Cutter compensation cancelG41 Cutter compensation leftG42 Cutter compensation rightG43 Tool length compensation (plus)G43 Tool length compensation (plus)G44 Tool length compensation (minus)G49 Tool length compensation cancelG80 Cancel canned cyclesG81 Drilling cycleG82 Counter boring cycleG83 Deep hole drilling cycleG90 Absolute positioningG91 Incremental positioning
- 9. Important M CodesM00Program stopM01 Optional program stopM02 Program endM03 Spindle on clockwiseM04 Spindle on counterclockwiseM05 Spindle stopM06 Tool changeM08 Coolant onM09 Coolant offM10 Clamps onM11 Clamps offM30 Program stop, reset to start
- 10. Modal and Non-ModalCommandsModal commands: Commands issued in the NC program that will stay in effect until it is changed by some other command, like, feed rate selection, coolant selection, etc.Nonmodal commands: Commands that are effective only when issued and whose effects are lost for subsequent commands, like, a dwell command which instructs the tool to remain in a given configuration for a given amount of time.
- 11. Open Loop andClosed Loop System
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- 13. Programming : Absoluteand Incremental5 – Parity check6 – Zero7- Minus8 – End of infoEIAASCII
- 14. Features of aCNC SystemsThe tool or material moves.Tools can operate in 1-5 axes.Larger machines have a machine control unit (MCU) which manages operations.Movement is controlled by a motors (actuators).Feedback is provided by sensors (transducers)Tool magazines are used to change tools automatically.
- 15. Types of InterpolationsPointto Point - No contouring capability Straight cut control - one axis motion at a time is controlled for machiningContouring - multiple axis’s controlled simultaneously
- 16. Sample ProgrammingPreparatory Information:units, incremental orabsolute positioningCoordinates: X,Y,Z, RX,RY,RZMachining Parameters: Feed rate and spindlespeedCoolant Control: On/Off, Flood, MistTool Control: Tool and tool parametersCycle Functions: Type of action requiredMiscellaneous Control: Spindle on/off, directionof rotation, stops forpart movementThis information is conveyed to the machine through a set of instructions arranged in a desired sequence – Program
- 17. Sample ProgrammingManual PartProgramming: Manual programming of the machinesComputer Aided Programming (CAP): Programming done by a computerManual Data Input (MDI): A manual program is entered into the machine’s controller via its own keyboard
- 18. Sample ProgrammingTool size= 0.25 inch,Feed rate = 6 inch per minute,Cutting speed = 300 rpm,Tool start position: 2.0, 2.0Programming in inchesMotion of tool:p0 p1 p2 p3 p4 p5 p1 p0
- 19. Sample ProgrammingSet upthe programming parametersProgramming in inchesUse absolute coordinatesFeed in ipmN010 G70 G90 G94 G97 M04 Spindle speed in rpmSpindle CCW
- 20. Sample ProgrammingSet upthe machining conditionsMachine moves in XY-planeUse full-circle interpolationFeed rateSpindle speedN020 G17 G75 F6.0 S300 T1001 M08 Tool no.Flood coolant ON
- 21. Sample ProgrammingMove toolfrom p0 to p1 in straight line Linear interpolationtarget coordinatesN030 G01 X3.875 Y3.698
- 22. Sample ProgrammingCut profilefrom p1 to p2Linear interpolationtarget coordinatesN040 G01 X3.875 Y9.125 orN040 G01 Y9.125 X-coordinate does not change no need to program it
- 23. Sample ProgrammingCut profilefrom p2 to p3Linear interpolationtarget coordinatesN050 G01 X5.634 Y9.125
- 24. Sample ProgrammingCut alongcircle from p3 to p4circular interpolation, CCW motiontarget coordinatesN060 G03 X7.366 Y9.125 I0.866 J-0.125 coordinates of center of circle (always in incremental )
- 25. Sample ProgrammingComplete ProgrammingN010G70 G90 G94 G97 M04 N020 G17 G75 F6.0 S300 T1001 M08 N030 G01 X3.875 Y3.698 N040 G01 X3.875 Y9.125 N050 G01 X5.634 Y9.125 N060 G03 X7.366 Y9.125 I0.866 J-0.125 N070 G01 X9.302 N080 G01 X3.875 Y3.698 N090 G01 X2.0 Y2.0 M30
- 26. Adaptive ControlAdaptive controlwith constraintsAdaptive control with optimization
- 27. Advantage of NCIncreasedproductivity Reduced tool/fixture storage and cost Faster setup time Reduced parts inventory Flexibility that speeds changes in design Better accuracy of partsReduction in parts handling Better uniformity of parts Better quality control Improvement in manufacturing control
- 28. DisadvantagesIncrease in electricalmaintenanceHigh initial investmentHigher per-hour operating cost than traditional machine toolsRetraining of existing personnelNC is a general term used for Numerical Control. CNC refers specifically to COMPUTER NUMERICAL CONTROL. CNC machines are all NC machines but not all NC machines are CNC machine.
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- 30. Turning, boring, milling,grinding etc.
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- 32. Turret punch press,pipe bending, flow forming etc.
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- 34. Wire-EDM, water-jet cutting,electron beam machining, laser beam machining, plasma cutting etc.
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- 38. Rapid Prototyping (RP)machinesNC is a control technique; not a process
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