CHHATTISGARH SWAMI VIVEKANAND TECHNICAL UNIVERSITY, BHILAI (C G)
Semester: B.E. VII Sem. Branch: Mechanical Engg.
Subject : Numerical Control of Machine Tools
Total Theory Periods: 50 Total Tutorial Period: 12
Total Marks in End Semester Exam: 80
Minimum number of class tests to be conducted: 2
UNIT – I
Fundamentals of numerical control, advantages limitations of N.C systems -classification of N.C systems.
Computer Numerical Control
Nomenclature, types and features of CNC machine tools. . Machine control unit. Position control and its
significance. Engineering analysis of NC positioning systems. Open loop and closed loop systems. Precision in NC
positioning systems: control resolution, accuracy and repeatability. Actuators: servomotors, stepper motors,
transducers and feedback elements.
UNIT – II
Features of N.C. Machine tools
Design consideration of N.C machine tools – increasing productivity with N.C machines, tooling for CNC machine.
Feed back system-counting devices digital analog converters
DDA integrators, simple and symmetrical DD reference word CNC interpolators.
UNIT – III
Process planning and flow chart for part programming. systems, nomenclature and tool geometries. Tool
presetting &Modular Tooling. Selection of tools based on machining capacity, accuracy and surface finish. Elements
of programming for turning and milling. part programming. Preparatory codes G, Miscellaneous functions M.
Interpolation, Tool compensations, cycles for simplifying programming. Typical part programming
Control Loops for N C Systems
Introduction-control loops for point and counting systems.
UNIT – IV
Computerized Numerical Control
CNC concepts-advantage of CNC reference planes, sampled data techniques, microcomputers in CNC.
Adaptive Control Systems
Adaptive control with optimization, and constraints-variable gains AC systems.
UNIT – V
Modern CNC machines
CNC lathes. Turning centers. Machining centres. Automatic pallet changers. Automatic tool changers. Direct
numerical control and applications. CNC machine design features.
1. Automation, Production Systems and Computer Integrated Manufacturing – Mikell P. Groover – PHI, 2001.
2. CNC Programming – S.K. Sinha – Galgotia Publications 2003.
HMT Mechatronics – Tata McGraw Hill
numerical control of machine tool by urie and koren