Dr. D. Y. PATIL SCHOOL OF ENGINEERING&TECHNOLOGY

INTRODUCTION OF COMPUTER NUMERICAL CONTROL MACHINE (CNC)

By,)

Under the guidance of,Prof..

INTRODUCTION CNC Machines What

is a CNC Machine?CNC : Computer and Numeric Control

Conventionally, 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.

Basic CNC Principles

•Each axis consists of a mechanical component, such as a slide that moves, a servo drive motor that powers the mechanical movement, and a ball screw to transfer the power from the servo drive motor to the mechanical component.

• 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.

Features of CNC Machinery

• The 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

APPLICATION• In the machine tool category, CNC is widely used for,

1. Lathe2. Drill press3. Milling machine4. Grinding unit5. Laser Cutting6. Sheet-metal press7. Tube bending machine etc.

TOOLS USED IN CNC

•Most are made from high speed steel (HSS), • tungsten carbide or ceramics.• Tools are designed to direct waste away from the material.• Some tools need coolant such as oil to protect the tool and work.

ADVANTAGES

1. high accuracy in manufacturing2. short production time3. greater manufacturing flexibility4. simpler fixturing5. contour machining (2 to 5 –axis machining)6. reduced human error

DISADVANTAGE

1. Costly setup2. Skilled operators3. Computers, programming knowledge required4. Maintenance is difficult

Thank You