Milling MachineMilling Machine

Definition:- A machine tool used for removing the Definition:- A machine tool used for removing the undesirable material from a workpiece by feeding undesirable material from a workpiece by feeding the workpiece past a rotating multipoint cutting tool the workpiece past a rotating multipoint cutting tool

called milling cutter.called milling cutter.Principle of operation: Principle of operation: Workpiece is clamped on the work table.Workpiece is clamped on the work table.Milling cutter is mounted on the arbor or spindle Milling cutter is mounted on the arbor or spindle of milling machine.of milling machine. Milling cutter rotates at desired speed.Milling cutter rotates at desired speed.Workpiece is fed against the rotating milling cutter Workpiece is fed against the rotating milling cutter in X,Y and Z directions.in X,Y and Z directions.Milling cutter is made up of material harder than Milling cutter is made up of material harder than the workpiece.the workpiece.

Principle of operationPrinciple of operation

Features of millingFeatures of milling Interrupted cutting:Interrupted cutting: A material is removed for only part A material is removed for only part

of the rotation of the milling cutter. As a result a cutting of the rotation of the milling cutter. As a result a cutting edge gets time to cool before it removes material again. edge gets time to cool before it removes material again. Thus milling is a cooler operation than turning operation.Thus milling is a cooler operation than turning operation.

Large material removal:Large material removal: Chip size is small but multiple Chip size is small but multiple cutting edges remove a large material in a single pass cutting edges remove a large material in a single pass than turning.than turning.

Variation in chip thickness:Variation in chip thickness: There is a cyclic variation There is a cyclic variation in chip thickness from zero to maximum. This is harmful in chip thickness from zero to maximum. This is harmful for surface finish and tool life.for surface finish and tool life.

ClassificationClassification Knee and column type:Knee and column type:Horizontal, Vertical, Universal and Turret.Horizontal, Vertical, Universal and Turret.These are general purpose milling machines with lot of These are general purpose milling machines with lot of

flexibility.flexibility. Production type:Production type: Simplex, Duplex, Triplex Simplex, Duplex, TriplexSuitable for large production of similar components, less Suitable for large production of similar components, less

flexibility.flexibility. Plano millers:Plano millers: Suitable for Large size workpieces. Suitable for Large size workpieces. Special purpose type:Special purpose type: Suitable for gear profiling, spline Suitable for gear profiling, spline

shaft manufacturing e.g. keyway milling, spline shaft shaft manufacturing e.g. keyway milling, spline shaft milling, etc.milling, etc.

Horizontal milling machineHorizontal milling machine

Vertical milling machineVertical milling machine

Components of milling machineComponents of milling machine Base:Base: lowermost part to support the machine lowermost part to support the machine Column:Column: Vertical part fixed on the base. Vertical part fixed on the base. Knee:Knee: The elevating screw moves it up and down The elevating screw moves it up and down Saddle:Saddle: Mounted on the knee, supports and provides Mounted on the knee, supports and provides

cross feed to the worktable.cross feed to the worktable. Worktable:Worktable: Movable table for clamping the workpiece. Movable table for clamping the workpiece. Over-arm:Over-arm: In horizontal milling machine to support the In horizontal milling machine to support the

arbor.arbor. Spindle:Spindle: Hollow shaft driven by motor to rotate milling Hollow shaft driven by motor to rotate milling

cuttercutter Arbor:Arbor: In horizontal milling to hold and rotate milling In horizontal milling to hold and rotate milling

cuttercutter

Operations performed on milling Operations performed on milling machinemachine

Plain milling:Plain milling: Up Up milling and down milling and down milling:- Machining is milling:- Machining is done by the teeth on done by the teeth on the cylindrical surface the cylindrical surface of the cutter, Finished of the cutter, Finished surface is parallel to surface is parallel to the axis of the cutterthe axis of the cutter

Operations performed on milling Operations performed on milling machinemachine

Face milling:Face milling: Machining is Machining is done by the teeth on the flat done by the teeth on the flat surface of the cutter, Finished surface of the cutter, Finished surface is perpendicular to the surface is perpendicular to the axis of the cutter. axis of the cutter.

Side milling:Side milling: Similar to face Similar to face millingmilling

Side and face milling:Side and face milling: Machining is done by the teeth Machining is done by the teeth on the flat as well as cylindrical on the flat as well as cylindrical surface of the cutter, finished surface of the cutter, finished surfaces are perpendicular as surfaces are perpendicular as well as parallel to the axis of well as parallel to the axis of the cutter.the cutter.

Operations performed on milling Operations performed on milling machinemachine

End milling:End milling: The machining is The machining is done by the cutter teeth on the done by the cutter teeth on the end as well as periphery of the end as well as periphery of the cutter. It is used for machining cutter. It is used for machining of complicated profiles.of complicated profiles.

Profile milling:Profile milling: The cutter has The cutter has outline same as that of the outline same as that of the shape of the profile. It is used shape of the profile. It is used for gear teeth manufacturing.for gear teeth manufacturing.

Gang milling:Gang milling: Two or more Two or more milling cutters are mounted on milling cutters are mounted on the arbor. Horizontal and the arbor. Horizontal and vertical surfaces are machined vertical surfaces are machined simultaneously.simultaneously.

Operations performed on milling Operations performed on milling machinemachine

Saw milling( Slitting):Saw milling( Slitting): The thickness of cutter is The thickness of cutter is small.(0.75 to 5 mm) It is small.(0.75 to 5 mm) It is used for cutting deep used for cutting deep slots or for cutting off slots or for cutting off operations.operations.

Keyway milling:Keyway milling: Keyways can be Keyways can be prepared by using side prepared by using side and face milling cutter on and face milling cutter on horizontal milling machine horizontal milling machine or end milling cutter on or end milling cutter on vertical milling machine.vertical milling machine.

Peripheral and face millingPeripheral and face milling

Milling CuttersMilling Cutters