CNC(KAPIL)

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GEETANJALI INSTITUTE OF TECHNICAL STUDIES

Presentation on

DEPARTMENT OF MECHANICAL ENGINEERING

CNC (Computer Numerical Control) machine

GITS IN-HOUSE TRANING

Approved by :- Prof. Vishnu Agarwal HOD,Mechanical

Submitted By :- Kapil vadiyar

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1. DESIGNING SOFTWARE SOLID WORKS ANSYS

2. WHEEL BALANCING AND WHEEL ALIGNMENT3. CNC LATHE MACHINE4. IC ENGINE

DISASSEMBLY REASSEMBLY

5. WELDING6. SOFT SKILLS

GITS IN HOUSE TRANING MODULE

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CONTENT• 1. Introduction• 2. What is CNC?• 3. History of CNC • 4. Classification of CNC machine• 5. Basic element of CNC machine• 6. Process of CNC• 7. CAD/CAM• 8. Part programming• 9. Basic G-codes• 10. Basic M-codes• 11. Process of program• 12. Advantages• 13. Challenges

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INTRODUCTION

• In Industry it is not efficient or profitable to make everyday products by hand.

• CNC machines can have several axes of movement, and these movements can be either linear or rotary. Many machines have both types.

• We use Siemens 802D CNC Lathe machine in our college.

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WHAT IS CNC?

• CNC Machining is a process used in the manufacturing sector that involves the use of computers to control machine tools.

• This means a computer converts the design into numbers which the computer uses to control the cutting and shaping of the material.

• CNC machine works like the Robot, which has to be fed with the program and it follows all your instructions.

Computer Numerical Control

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CLASSIFICATION OF CNC MACHINE

Classification of CNC

Based on Motion

Point-to-point

Based on Feedback

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HISTORY OF CNC

• 1949:US Air Force asks MIT to develop a "numerically controlled" machine.

• 1952:Prototype NC machine demonstrated (punched tape input).

• 1980:CNC machines (computer used to link directly to controller) • 1990:DNC: external computer “drip feeds” control programmer

to machine tool controller

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BASIC ELEMENTS OF CNC MACHINE

A CNC machine consist of following 6 major elements:-

1. Input Device2. Machine control unit3. Machine tools4. Driving system5. Feedback devices6. Display unit.

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BLOCK DIAGRAM OF CNC

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PROCESS OF CNC

• The computer is used to draw the design. However, the design is only a picture and the CNC machine cannot use this to manufacture the product. The computer software must also convert the drawing into numbers (coordinates) .

A Computer

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CAD/CAM

• CAM – Computer Aided Machining or Manufacturing – Refers to the use of various software packages to create tool paths and NC code to run a CNC controlled machine, based on 3D computer model (CAD) data. When the two are used together, this is generally referred to as CAD/CAM.

• Note: CAM does not actually run the CNC machine, but just creates code for it to follow.

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PART PROGRAMMINGPrepare the process plan

Identify the machine tool

Select the drive axis

Choose the tool

Determining the machining parameter

Make job and tool set-up plan

Decide the tool path

Write the part program

Test the part program

Document the program

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PROGRAMMING FUNCTION

Preparatory function G- code

Miscellaneous function M- code

Speed function S- code

Feed rate F- code

Tool function T- code

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BASIC G-CODESCodes FunctionsGOO Linear interpolation at rapid motion

GO1 Linear interpolation at feed rate

GO2 Circular interpolation(clockwise )

G03 Circular interpolation(anti-clockwise)

GO4 Dwell timeG70 Inch modeG71 Millimeter modeG75 Reference position(home position)

G94 mm per minute G95 mm per revolution

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BASIC M-CODESCodes Function

M00 Program stop

M01 Optional stop

M02 End of program

M03 Spindle clockwise

M04 Spindle anti clockwise

M05 Spindle OFF

M06 Tool change

M08 Coolant ON

M09 Coolant OFF

M10 Chuck open

M11 Chuck close

M16 Auto tool change

M30 End of tape/ tape rewind

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PROCESS OF PROGRAM

Start up program

Tool position

Profile program

End of program

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EXAMPLEG71 G95G75 X0Z0M16 T1M03 S1000G00 X32Z2G00 X29G01 Z-10 F0.1G01 X30G00 Z2G00 X28G01 Z-10 F0.1G01 X30G00 Z2G75 X0Z0M05M30

RPM = CUTTING SPEED(V.C) X 1000 ∏ X D

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ADVANTAGES OF CNC

• Increase production throughput• Improve the quality and accuracy of manufactured

parts• Stabilize manufacturing costs• Manufacture complex or otherwise impossible jobs -2D

and 3D contours• Less skilled/trained people can operate CNC’s

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CHALLENGES

• Costly setup• Skilled operators required• Programming knowledge required• Maintenance is difficult.

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REFERENCES

• www.google.com• www.wikipedia.com• CAD/CAM books• Training report.

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Any Questions?

THANKS!