1955 - US Air Force define a need to develop a machine tool capable of machining complex and close tolerance aircraft parts.

1959 - MIT is the contractor and builds the machine for the project. MIT announces Automatic Programmed Tools (APT) programming language

1960 - Direct Numerical Control (DNC). This eliminates paper tape and allows programmers to send files directly to machine tools

1980’s - CNC machine is introduced. Unix and PC based systems

1997 - PC- Windows operating system is attached to cnc

Turning Centers

Milling Centers

Vertical Machining Centers

Horizontal Machining Centers

Drilling Machines

EDM Machines

Laser-Cutting Machines

Spindle in a vertical orientation.

VMCs are high-precision

Used for tight-tolerance

Spindle in a horizontal orientation.

Horizontal orientation encourages

chips to fall away.

HMCs are high-precision

Used for tight-tolerance

Controlled by G and M codes.

These are number values and co-ordinates.

Each number or code is assigned to a particular operation.

Typed in manually to CAD by machine operators.

G & M codes are automatically generated by the computer software.

O - Program number N - Sequence number G - Preparatory function X - X axis designation Y - Y axis designation Z - Z axis designation R - Radius designation F – Feed rate designation S - Spindle speed designation H - Tool length offset designation D - Tool radius offset designation T - Tool Designation M - Miscellaneous function

G00 Rapid Transverse G01 Linear Interpolation G02 Circular Interpolation, CW G03 Circular Interpolation, CCW G20/G70 Inch units G8 Cancel canned cycles G81 Drilling cycle G82 Counter boring cycle G83 Deep hole drilling cycle G90 Absolute positioning G91 Incremental positioning

M00 Program stop M01 Optional program stop M02 Program end M03 Spindle on clockwise M04 Spindle on counterclockwise M05 Spindle stop M06 Tool change M08 Coolant on M09 Coolant off M10 Clamps on M11 Clamps off M30 Program stop, reset to start

Automobile Part

Aerospace

CNC machine manufactures this items

Diamond & Jewellery Ind.

Textile Machinery

Die & Mould Manufactures

• Posess hardness and strength at high temperatures

• Able to withstand when heat is generate

• Angle of the cutting face

• Flute width, number of flutes, teeth, and margin size

Lubricating during cutting process

Cooling the workpiece at high cutting speeds

Improving tool life,

Improving surface finish

Flushing away chips from the cutting zone

Corrosion protection of the machined surface

STRAIGHT OILS -Non-emulsifiable and are used in machining operations in an undiluted form they are composed of a petroleum oil , lubricants such as fats, vegetable oils

( BEST LUBRICATION )

SOLUBLE OILS -Contain no petroleum or mineral oil , composed of alkaline inorganic and organic compounds ( BEST COOLING )

SEMISYNTHETIC FLUIDS- Emulsion when mixed with water

( LEAST EXPENSIVE )

SYNTHETIC FLUIDS-Combination of synthetic and soluble oil fluids

( COST AND HEAT TRANSFER PERFORMANCE )

High Accuracy e.g. Aircraft parts

Production rate is very high

Complex surfaces need to be machined

Flexibility in job change , automatic tool settings

More safe , higher productivity , better quality

Less paper work , faster prototype production

Costly setup

Skilled operators

Computers , Programming knowledge required

Maintenance is very difficult

.