CNC MACHINE Introduction-1

		Home Teachers Education INDIA
COMPUTER AIDED MANUFACTURING ME0407 CAD&CAM LECTURE NOTES by: Devendra Singh Even 2015-2016 Dept. of ME Funded with Home Teachers Education INDIA 1
		COMPUTER AIDED MANUFACTURING TOPICS
•  Numerical Control Systems (NC,CNC) and Machine Tools •  Numerical Part Programming (Manual and Automatic/CAPP) •  CAD-CAM-CNC Systems Integration •  Automation in Manufacturing and Computer Integrated Manufacturing (CIM) •  Flexible Manufacturing Cells (FMC) and Systems (FMS) •  Sensors and Process Monitoring Systems •  Rapid Prototyping Methods •  Computer Aided Special and Nontraditional Manufacturing Methods 2
		ME0407 CAM Notes by Home Teachers Education INDIA
DEFINITION: Effective utilization of computer technology in the MANAGEMENT, CONTROL and OPERATIONS of the manufacturing facility through either direct or indirect computer interface with the physical and human resources of the company (after CAMI). Dominant Operation: Numerical Control (NC) part programming Common (and narrower) concept for CAM: Computer assisted part programming Logical Starting point: Manual part programming 3
		NUMERICAL CONTROL (NC) ME0407 CAM Notes by Home Teachers Education INDIA
DEFINITION: The control of operation of machine tools (M/T) (or other sheet-working and welding machines) by a series of coded instructions called the program, which consists mainly of alphanumeric characters (nembers and letters). Main Characteristics: Preplanned and predictable Therefore, NC is a typical form of: Programmable Automation. 4

BRIEF HISTORY OF CNC M/T

                                  Time                      Characteristic                                     Description

Early Industrial             J.Jackard’s method to control textile Revolution           Basic Concept      looms by using punched cards.

2^nd World War                                                         2D Manual Applications           Parson’s 2-D Coordinate table operated by two people

                        1947                      1^st modern concept               Parsons’ NC proposal for milling

helicopter rotor blades

                        1952              version1^st effectively functioning MIT’s first NC Milling machine

1956                                                                        1^st industrial contract  USAF’s contract for 100 NC Milling machines to 8 co.s

1956^• -1962                                                           Difficult years              Big opposition against NC M/T in the contractors of USAF

                        1961                     1^st industrial success             Point-to-point control drill pressed

1970                                                                        1^st CNC         Storing the programs on a computer in add. to tapes.

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		ADVANTAGES OF NC ME0407 CAM Notes by Home Teachers Education INDIA
•     NC M/T ensure positioning accuracy and repeatibility with their DESIGN, CONSTRUCTION and CONTROLS: Good for making many of the same part. •     Complex shaped components can be made automatically, with high precision and reliability. •     Parts that require a long series of operation can be made with minimal accumulated error. •     NC M/T can operate in hostile and hazardous environments. •     Since most work is shifted to offices from the shop-floor, production can be monitored by the management directly. •     NC M/T mostly are capable of conducting more than one machining operation at a time or in a sequence without repeating the part set-up. •     Minimum idle time and increased productivity. •     Interchangeability of work between different production plants. 6