This document discusses the features of CNC machines. It describes the main components of CNC machines including the central processing unit, memory, input/output interface, controls for machine axes and spindle speed, and programmable logic controller. It provides details on what each component does and how it functions within the CNC system. In conclusion, it states that while the initial costs of CNC machines are high, profits will increase once the machines are operational.

1. Excel polytechnic college
DEPARTMENT OF MECHANICAL
ENGINEERING

2. SEMINAR
SPECIAL MACHINES

3. Title : FEATURES OF CNC MACHINES
Subject : SPECIAL MACHINES
Section :C
Department: Mechanical
Member
:DineshPiran G
:Arithas
:Anbu selvan . V
:damchuilang gangmei
:dheeraj kumar rajak
:elakkiyan . P

4. CONTENTS
• INTRODUCTON
• DIAGRAM
• FEATURES
• EXPLATION
• CONCLUSION

5. INTRODUCTION
Numerical control is in automation
where controlling of machine tool is by
means of prepared program containing
series of numbers. These numbers
define the required position of each
slide, its cutting speed etc…. The
programme is designed for a particular
job.

6. diagram

7. Features of cnc machines
Central processing unit
Memory
Input / output interface
Controls for machine tools axes & spindle
speed
Programmable logic controller

8. CPU = CENTRAL PROCESSING UNIT
 The central processing unit
is the brain of the MCU.
 It manage other
components in the MCU
with the help of software
contained in the main
memory.
 The control section
retrieves commands and
data from memory and
generates signal in the
MCU.

9. MEMORY
It can be divided into
main memory and
secondary memory.
The main memory
consists of ROM {Read
Only Memory} and RAM
{Random Access
Memory} devices.
Operating system
software and machine
interface programs are
generally stored in the
RAM.

10. INPUT / OUTPUT INTERFACE
The input / out put interface provides
communication between the various
components of the CNC system, other
computer systems and machine
operator.
The machine operator communicates to
the CNC system through the control
panel.
Display is for communication of data
and information from the MCU to the
machine operator.

11. Controls for machines to axes and spindle speed
These are hardware components that
controls the position and velocity of each
machine axis as well as rotational speed
of machine tool spindle.
The control signals generated by MCU
must be converted to the position control
system used to drive the machine axes.
Spindle speed controls components in the
MCU consists of a drive control circuit and
a feed back sensor interface.

12. PLC = PROGRAMMABLE
The programmable logic controller is
used to manage the input / output
interface for auxiliary functions such as
logical sequencing, timing, counting and
arithmetic functions.
These auxiliary functions are generally
ON / OFF actuations, interlocks and
discrete numerical data.
PLC can be reprogrammed according to
the changes in the control functions.

13. Conclusion
Further analysis shows that the cost
initially will be high but the profits will
grow once everything is operational.
The final consultation would be to
agree with implementing these
machines into the company.