Q1: What is a Numerical Control System (NC System)?
Ans: A Numerical Control System is a manufacturing system in which machine operations are controlled by numerical instructions in the form of codes.
Q2: What is the NC/CNC Program?
Ans: An NC/CNC program is a set of coded instructions that tells the machine how to move tools and perform machining operations.
Q3: Name the types of NC/CNC Programming.
Ans: The types of NC/CNC programming are as followsare:
- ➔ Manual Programming
- ➔ Computer-Assisted Programming
Q4: Write the types of Programming.
Ans: The types of programming include:
- ➔ Absolute Programming
- ➔ Incremental Programming
Q5: What are the components of a Numerical Control System?
Ans: Main components of an NC system are as follows:
- ➔ Input device
- ➔ Controller
- ➔ Machine tool
- ➔ Feedback system
Q6: Name the media of data storage.
Ans: Data storage media are as follows:
- ➔ Paper tape
- ➔ Magnetic tape
- ➔ Disk drives
- ➔ Computer memory
Q7: What is the purpose of Tape Reader?
Ans: A tape reader reads the punched tape and sends the instructions to the controller.
Q8: What is the purpose of Tape Punch?
Ans: A tape punch is used to prepare or modify punched tapes by creating holes that represent instructions.
Q9: What is the purpose of the Controller?
Ans: The controller interprets program instructions and controls the movement of the machine tool.
Q10: What is an NC Machine?
Ans: An NC machine is a machine tool that operates automatically using numerical control instructions.
Q11: What is MCU (Machine Control Unit)?
Ans: MCU is the control unit that processes input data and controls machine movements.
Q12: What is a Computer Numerical Control System (CNC System)?
Ans: A CNC system is an advanced NC system where a computer is used to control machining operations.
Q13: What is a Computer Numerical Control Machine (CNC Machine)?
Ans: A CNC machine is a machine tool controlled by a computer using programmed instructions.
Q14: Write the working of a CNC Machine.
Ans: The working of a CNC machine is as follows:
- ➔ Program is entered into the computer
- ➔ Controller interprets the program
- ➔ Motors move the tool/workpiece
- ➔ Machining operation is performed
Q15: Write the working of an NC Machine.
Ans: The working of an NC machine is as follows:
- ➔ Program is prepared on punched tape
- ➔ Tape is read by tape reader
- ➔ Controller sends signals
- ➔ Machine performs operation
Q16: Briefly state the history of Numerical Control.
Ans: Numerical Control was developed in the 1950s to automate machine tools using punched tape systems.
Q17: Name four advantages of Numerical Control System (NC System)?
Ans: Some of the advantages of NC system are as follows:
- ➔ High accuracy
- ➔ Increased productivity
- ➔ Reduced human error
- ➔ Consistent quality
Q18: Name four disadvantages of Numerical Control System (NC System)?
Ans: Some of the disadvantages of NC system are as follows:
- ➔ High initial cost
- ➔ Complex maintenance
- ➔ Skilled operators required
- ➔ Limited flexibility
Q19: Compare NC Machine and CNC Machine?
Ans: Comparison between NC and CNC machines is as under:
- ➔ NC uses punched tape, CNC uses computer memory
- ➔ CNC is more flexible than NC
- ➔ CNC allows easy program editing
Q20: List the operations of a Numerical Control Machine Tool?
Ans: Operations include:
- ➔ Turning
- ➔ Drilling
- ➔ Milling
- ➔ Grinding
Q21: Define Process Planning.
Ans: Process planning is the systematic determination of manufacturing steps required to produce a part.
Q22: Define Machining.
Ans: Machining is a manufacturing process in which material is removed to shape a workpiece.
Q23: Define Turning in Machine Operation.
Ans: Turning is a machining operation where material is removed using a rotating workpiece.
Q24: Define Taper Turning in Machine Operation.
Ans: Taper turning produces a conical surface by gradually reducing the diameter of the workpiece.
Q25: Define Contour Turning in Machine Operation.
Ans: Contour turning produces curved or irregular shapes on a rotating workpiece.
Q26: Name the factors controlling Turning in Machine Operation.
Ans: Factors controlling turning are as follows:
- ➔ Cutting speed
- ➔ Feed rate
- ➔ Depth of cut
Q27: Define Facing in Machine Operation.
Ans: Facing is the operation of machining the flat surface at the end of a workpiece.
Q28: Define Drilling in Machine Operation.
Ans: Drilling is the operation of creating a circular hole using a rotating drill.
Q29: Define Boring in Machine Operation.
Ans: Boring enlarges an existing hole to improve accuracy and finish.
Q30: Define Threading in Machine Operation.
Ans: Threading is the process of cutting screw threads on a workpiece.
Q31: Define Milling in Machine Operation.
Ans: Milling removes material using a rotating multi-point cutting tool.
Q32: Define Knurling in Machine Operation.
Ans: Knurling creates a patterned surface for better grip.
Q33: Define Parting in Machine Operation.
Ans: Parting is the operation of cutting off a finished part from the workpiece.
Q34: Define Grinding in Machine Operation.
Ans: Grinding is a finishing process that uses an abrasive wheel to improve surface finish.
Q35: Define Hobbing in Machine Operation.
Ans: Hobbing is a machining process used to cut gear teeth.
Q36: What is an APT Program?
Ans: APT (Automatically Programmed Tool) is a high-level programming language used for NC machines.
Q37: When was the APT Program developed?
Ans: APT was developed in the late 1950s.
Q38: What is Program Coding in NC Machine Tool Operation?
Ans: Program coding is the process of converting machining instructions into numerical codes.
Q39: What is a Process Sheet?
Ans: A process sheet is a document that lists machining steps, tools, and parameters.
Q40: What is Servomechanism?
Ans: A servomechanism is a control system used to accurately control machine movement.
Q41: What is an Encoder?
Ans: An encoder is a feedback device that converts motion into electrical signals.
Q42: What is a Controller?
Ans: A controller is a device that manages and controls machine tool operations.
Q43: What are Micro-computers?
Ans: Micro-computers are small computers that use a microprocessor as the CPU.
Q44: When were Micro-computers invented?
Ans: Micro-computers were invented in the early 1970s.
