CNC MACHINES

(COMPUTER NUMERICAL

CONTROL)

By

S. Hemanth

Computer Numerical Control

Computer Numerical Control (CNC) is one in

which the functions and motions of a machine

tool are controlled by means of a prepared

program containing coded alphanumeric data.

CNC can control the motions of the workpiece

or tool, the input parameters such as feed,

depth of cut, speed, and the functions such as

turning spindle on/off, turning coolant on/off.

Types of CNC Machines

Horizontal Machining centre

Vertical Machining centre

Turning Machining centre

HMC Machine

Horizontal Machining

Centers (HMCs)

Spindle is a horizontal orientation

Horizontal orientation encourages

chips to fall away

HMCs are high-precision

Used for tight-tolerance

HMC Working Operations

VMC

Machine

Vertical Machining Centers

(VMCs)

Spindle in a vertical orientation.

VMCs are high-precision

Used for tight-tolerance

VMC Working Operations

Turning Machine

Turning Machining centre

Spindle and tool

are in horizontal

plane

Runs two or more

spindles

Runs 24 hours

TMC Working Operations

Favourable specks

High accuracy in manufacturing

Short production time

Greater manufacturing flexibility

Simpler fixturing

Contour machining (2 to 5 axis machining)

Reduced human error and effort

Unfavourable specks

High cost

Maintenance is difficult

Skilled part programmer is required