Q1: What is a Milling Machine?
Ans: A milling machine is a machine tool used to remove material from a workpiece by using a rotating cutting tool. It is mainly used for shaping and cutting solid materials like metal.
Q2: Write any four uses of the Milling Machine.
Ans: The uses of a milling machine are as follows:
- ➔ Cutting and shaping metal surfaces
- ➔ Making slots and grooves
- ➔ Producing gears and threads
- ➔ Drilling and boring operations
Q3: What is the working principle of a Milling Machine?
Ans: The working principle of a milling machine is based on the rotation of a cutting tool.
The cutter rotates at high speed and removes material from the stationary or moving workpiece.
Q4: Briefly discuss the working of a Milling Machine.
Ans: In a milling machine, the workpiece is fixed on the table.
A rotating cutter removes unwanted material from the workpiece.
The table can move in different directions to get the required shape and size.
Q5: Name the types of Milling Machines.
Ans: The types of milling machines are:
- ➔ Vertical Milling Machine
- ➔ Horizontal Milling Machine
- ➔ Universal Milling Machine
- ➔ Planner Milling Machine
- ➔ Bed Type Milling Machine
- ➔ Duplicating Milling Machine
- ➔ Duplex Milling Machine
- ➔ Column and Knee Type Milling Machine
Q6: Briefly explain Vertical Milling Machine.
Ans: In a vertical milling machine, the spindle is placed vertically.
The cutting tool rotates in a vertical direction.
It is mainly used for face milling and end milling operations.
Q7: Briefly explain Horizontal Milling Machine.
Ans: In a horizontal milling machine, the spindle is placed horizontally.
The cutter rotates in a horizontal direction.
It is used for heavy cutting and large workpieces.
Q8: Briefly explain Universal Milling Machine.
Ans: A universal milling machine can perform multiple operations.
Its table can be swiveled to different angles.
It is used for complex and angular machining work.
Q9: Briefly explain Planner Milling Machine.
Ans: A planner milling machine is used for machining large surfaces.
The workpiece moves while the cutter remains stationary.
It is suitable for heavy and large jobs.
Q10: Briefly explain Bed Type Milling Machine.
Ans: In a bed type milling machine, the table is fixed on the bed.
The spindle moves vertically to perform cutting.
It is used for heavy-duty operations.
Q11: Briefly explain Duplicating Milling Machine.
Ans: A duplicating milling machine is used to copy the shape of a model.
It follows a template to produce identical parts.
It is commonly used in mass production.
Q12: Briefly explain Duplex Milling Machine.
Ans: A duplex milling machine has two spindles.
It can machine two surfaces at the same time.
It increases productivity and saves time.
Q13: Briefly explain Column and Knee Type Milling Machine.
Ans: This type of machine has a vertical column and an adjustable knee.
The knee supports the table and can move up and down.
It is widely used in workshops for general machining.
Q14: What is a Pantograph?
Ans: A pantograph is a mechanical device used to copy or reproduce a design at a different scale, either larger or smaller.
Q15: Briefly explain the working of a Pantograph.
Ans: A pantograph works by tracing a design with a pointer.
The movement is transferred through linked arms.
It produces a scaled copy of the original design.
Q16: Define Slab Milling.
Ans: Slab milling is a machining process in which a flat surface is produced by using a rotating cutter with teeth on its periphery.
Q17: Define Gang Milling.
Ans: Gang milling is a process in which multiple cutters are used together on one arbor to perform different operations at the same time.
Q18: State the driving mechanism of Milling Machine
Ans: The driving mechanism of a milling machine includes:
- ➔ Electric motor
- ➔ Belt and pulley system
- ➔ Gear mechanism
Q19: Name the parts of a Milling Machine.
Ans: The main parts of a milling machine are:
- ➔ Base
- ➔ Column
- ➔ Knee
- ➔ Table
- ➔ Spindle
- ➔ Arbor
- ➔ Over Arm
- ➔ Arbor Support
Q20: What is a Work Piece in a Milling Machine?
Ans: A workpiece is the material or object that is fixed on the machine table and is being cut or shaped during the milling operation.
Q21: What is a Base in a Milling Machine?
Ans: The base is the bottom part of the milling machine. It supports the entire machine and provides stability.
Q22: What is a Column in a Milling Machine?
Ans: The column is a vertical structure mounted on the base. It supports the spindle and other parts of the machine.
Q23: What is an Over Arm in a Milling Machine?
Ans: The over arm is a horizontal bar that supports the arbor. It provides rigidity and stability during machining.
Q24: What is an Arbor Support in a Milling Machine?
Ans: Arbor support is a part that holds and supports the outer end of the arbor. It helps reduce vibration during cutting.
Q25: What is a Knee in a Milling Machine?
Ans: The knee is a movable part that supports the table. It can move up and down to adjust the position of the workpiece.
Q26: What is a Spindle in a Milling Machine?
Ans: The spindle is a rotating part of the milling machine that holds and drives the cutting tool. It provides motion to the cutter.
Q27: What is a Saddle in a Milling Machine?
Ans: The saddle is a part mounted on the knee that supports the table. It allows movement of the table in a cross direction.
Q28: What is Swivelling Table Housing in a Milling Machine?
Ans: The swivelling table housing allows the table to rotate at different angles. It is used for angular and complex machining operations.
Q29: State the use of the Work table in Milling Machine.
Ans: The work table is used to hold and support the workpiece during machining operations. It can move in different directions to position the workpiece properly.
Q30: What is a Vertical Feed Crank in a Milling Machine?
Ans: The vertical feed crank is used to move the knee or table up and down. It helps in adjusting the vertical position of the workpiece.
Q31: What is a Table Hand Wheel in a Milling Machine?
Ans: The table hand wheel is used to move the table in the longitudinal direction (left and right).
Q32: What is a Cross Hand Wheel in a Milling Machine?
Ans: The cross hand wheel is used to move the table in the cross direction (in and out).
Q33: What is a Coolant Pump in a Milling Machine?
Ans: A coolant pump supplies coolant fluid to the cutting area. It helps in cooling, lubrication, and removing chips.
Q34: Which coolant is used in a Milling Machine?
Ans: The commonly used coolants are:
- ➔ Water-soluble oil
- ➔ Cutting oil
- ➔ Synthetic coolant
Q35: What is a Belt Drive in a Milling Machine?
Ans: A belt drive is a mechanism that transmits power from the motor to the spindle using belts and pulleys.
Q36: What is a Feed Change Gear Box in a Milling Machine?
Ans: The feed change gear box is used to control and change the speed of feed movement of the table.
Q37: What are Longitudinal Feed Trip Dogs in a Milling Machine?
Ans: These are devices used to automatically stop or reverse the table movement in the longitudinal direction.
Q38: What are Vertical Feed Trip Dogs in a Milling Machine?
Ans: These are used to control and stop the vertical movement of the table or knee automatically.
Q39: What are Cross- Feed Trip Dogs in a Milling Machine?
Ans: These are used to control and stop the cross movement of the table automatically.
Q40: What are Wiper Pads in a Milling Machine?
Ans: Wiper pads are used to clean dirt, chips, and dust from machine guideways. They help in smooth movement and reduce wear.
Q41: What is the function of the Main Drive Box in a Milling Machine?
Ans: The main drive box controls the speed and power of the spindle. It helps in selecting different cutting speeds.
Q42: What are Trip Dogs in a Milling Machine?
Ans: Trip dogs are adjustable stops that control the automatic movement of the table. They help in stopping or reversing motion.
Q43: Briefly discuss the care and maintenance of a Milling Machine?
Ans: Care and maintenance include:
- ➔ Regular cleaning of machine parts
- ➔ Proper lubrication of moving parts
- ➔ Checking alignment and adjustments
- ➔ Avoiding overloading
- ➔ Keeping the machine dry and rust-free
Q44: What is a Gib?
Ans: A gib is a thin strip used to adjust and control the clearance between sliding parts of the machine.
Q45: What is Gib Adjustment?
Ans: Gib adjustment is the process of tightening or loosening the gib to remove play and ensure smooth movement.
Q46: What is Table Gib Adjustment?
Ans: Table gib adjustment is done to remove looseness in the table movement and ensure smooth sliding.
Q47: What is Saddle Gib Adjustment?
Ans: Saddle gib adjustment is used to control the movement of the saddle and remove any unwanted play.
Q48: What is Knee Gib Adjustment?
Ans: Knee gib adjustment is done to ensure proper vertical movement of the knee without looseness.
Q49: State at least six safety precautions while operating a Milling Machine.
Ans: The safety precautions are:
- ➔ Wear proper safety equipment
- ➔ Do not wear loose clothes
- ➔ Keep hands away from rotating cutter
- ➔ Secure the workpiece properly
- ➔ Stop the machine before adjustments
- ➔ Keep the work area clean
Q50: State the dress code in a workshop while operating the Milling Machine.
Ans: The dress code includes:
- ➔ Wear fitted clothes
- ➔ Use safety shoes
- ➔ Wear goggles
- ➔ Avoid jewelry and loose items
Q51: Write the importance of Work Station Light while working with a Milling Machine.
Ans: Work station light is important because:
- ➔ It improves visibility
- ➔ Helps in accurate machining
- ➔ Reduces chances of errors
- ➔ Increases safety
Q52: State any four House Keeping precautions regarding Milling Machines.
Ans: The housekeeping precautions are:
- ➔ Keep the floor clean and dry
- ➔ Remove chips regularly
- ➔ Arrange tools properly
- ➔ Maintain cleanliness around the machine
