Basic CNC Machines working

1. PRESENTED BY
AKSHAY SINGH
B-TECH(ECE)
COMPUTER NUMERICALLY CONTROLLED
MACHINE

2. OUTLINE
• ABOUT BHEL
• CNC MACHINE
• CONFIGURATION
• MODES OF OPERATION
• PROGRAMMING
• MEMORY CONCEPT
• ADVANTAGES
• ENCODERS AT HERP
• REFERENCES

3. BHEL
• The foundation stone of HERP was laid on
26th September 1984.
• It is sprawled in 29.8 acres area at Varanasi.
• After 21 months production activities were
started (1st April'1986).
• It has taken jobs from NTPC Tanda,
UPRVUNL Obra.
• Now apart from jobs it is also manufacturing
& supplying turbine fasteners.

4. HERP, VARANASI

5. PRODUCTS
• Bowl Mill spares for XRP/XRS 623, 703HP.
• Spares for Boiler Auxiliaries like Coal Burners,
Fuel Piping, Air Preheater.
• Hydro Turbine component machining like
Guide Vanes, Guide Bearings, Thrust Pad etc.
• Rabbeting of TG bearings.
• Main Components/Spares: Main vertical shaft,
Bowl Hub.

6. CNC MACHINES
• A computer numerical control (CNC) is a
microprocessor-based system.
• It store and process the data for the control of slide
motions and auxiliary functions of the machine tools.
• Numerical control (NC) is a method employed for with
input in the form of numerical data.
• The CNC systems are constructed with a NC unit
integrated with a programmable logic controller (PLC).
• Positioning and part accuracy depend on the CNC
system's computer control algorithms.

7. SCHEMATIC DIAGRAM OF A CNC
MACHINE TOOL

8. ENCODERS
• Angle Encoders- Encoders that have an
accuracy of better than ± 5”.
• Rotary Encoder- Encoders that have an
accuracy of more than ± 10”.
• Absolute Encoder- Encoders featuring
multiple coded graduation tracks.
• Incremental Encoder- Encoders having
a periodic grating structure.

9. MODES OF OPERATION
• MANUAL MODE- In this mode, movement of a
machine slide can carried out manually by pressing the
particular jog button .
• In this mode slides can be moved in two ways:
 Continuous mode- The slide will move as long
as the jog button is pressed.
 Incremental mode- The slide will move through
a fixed distance, which is selectable.
• MANUAL DATA INPUT (MDI) MODE- Building,
editing or deleting a part program stored in the system
memory .

10. • AUTOMATIC MODE (AUTO AND SINGLE BLOCK):
In this mode the system allows the execution
of a part program continuously.
The part program is executed block by block.
Selection of part program execution continuously
(Auto) or one block at a time (Single Block) is done
through the machine control panel.
• REFERENCE MODE:
Under this mode the machine can be referenced to
its home position is required.
All the compensations (e.g., pitch error
compensation) can be properly applied.

11. PROGRAMMING

12. G & M CODES

13. MEMORY CONCEPT
• LOAD MEMORY- It is used for storing code
blocks and data blocks, as well as system
data (configuration, connections, module
parameters etc.)
• MAIN MEMORY- Its only purpose is
processing of code and user program data.
• SYSTEM MEMORY- It contains the address
areas for memory bits, timers and counters.

14. ADVANTAGES
• Increased productivity.
• Consistent quality
• Reduced scrap rate
• Reduced manpower
• Automatic material handling
• Just in time (JIT) manufacture
• High accuracy
• Machining of advanced material

15. ENCODERS
Encoder Machine Description
Heidenhain ROD 486 2500 03 S12-03 MARIO
Incremental
Rotary Type
Heidenhain ROD 486 1024 03 S12-03 MARIO
Incremental
Rotary Type
BALLUFF Incremental Encoder SBCNC-55
Incremental
Rotary Type
KUBLER Incremental Encoder SBCNC-55
Incremental
Rotary Type
ENCODER 6FX2001-3AC50. NH 26 CNC
Incremental
Rotary Type
ENCODER 6FX2001-3CC50. HMC-650
Incremental
Rotary Type
ENCODER 6FX2001-3CB02. HMC-650
Incremental
Rotary Type
HEIDENHAIN RON 287 HMC-650
Angle Encoder
Incremental
LINEAR SCALE HEIDENHAIN LC
182 SET HMC-650
Linear Scale
Absolute

16. REFERENCES
• http://www.machinemate.com/FullListCodes.h
tm.
• https://en.wikipedia.org/wiki/G-code.
• https://en.wikipedia.org/wiki/CNC_router.
• http://jyoti.co.in/product-category/turning-
centers/simple-turning-centers/.
• http://www.brighthubengineering.com/manufa
cturing-technology/55787-what-is-the-cnc-
machine-how-cnc-machine-works/.

17. THANK YOU