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Milling MachinesBy
Avinash N. Fulbaria
ContentIntroductionMilling ParametersTypes of Milling MachineMilling OperationsMilling CuttersComponents Of Milling MachineReference
Milling Or Milling MachineMilling: a
process in which a rotating multi-tooth cutter removes material while traveling along various axes with respect to the work piece.
Cutter
Workpiece
Milling Parameters Cutting speed : it is the peripheral
speed of the milling cutter relative to the work.
V= πdN m per minute 1000 where V= cutting speed d = Diameter of cutter in mm N = RPM of cutter
Milling ParametersFeed : It is ratio of linear speed of
workpiece to the product of number of teeth and rpm of cutter.
F = V NnWhere , V = linear speed of
workpiece n = number of teeth
Milling ParameterMilling Time : t = l + la V l = Length of workpiece la = approach length
Milling ParameterMetal Removal Rate MRR = lwb tWhere w = width of the cut
Types of Milling MachineConventional milling machineBed type milling machine Column- knee type milling
machine CNC milling machine (VMC)
Column and Knee Type Milling m/c
Bed Type Milling m/c
CNC Milling m/c
Milling OperationsPeripheral milling Face millingEnd milling
Peripheral MillingIn peripheral
milling (also called plain milling), the axis of cutter rotation is parallel to the work piece surface.
Up milling Down milling
Face Milling The cutter is
mounted on a spindle whose axis of rotation is perpendicular to workpiece surface.
Tool
Workpiece
Milling CuttersStraddle: More cutters are used to machine two
parallel surfaces on the workpiece.
Form milling : It produces curved profiles using cutters that have specially shaped teeth.
Slotting and slitting operations are performed with circular cutters. Eg.T-slot cutters
Slotter Cutter
Components Of Milling MachineWorktable: on which the work piece is clamped
using T-slots. The table moves longitudinally relative to the saddle.
Saddle: supports the table and can move in the transverse direction.
Knee: supports the saddle and gives the table vertical movement so that the depth of cut can be adjusted and work pieces with various heights can be accommodated.
Overarm: used on horizontal machines; it is adjustable to accommodate different arbor lengths.
Head: contains the spindle and cutter holders.
ReferenceS.K. Hajra Choudhary , A.K. Hajra
Choudhary , Nirjhar Roy , Elements of Workshop Technology , Vol 2 (12th Edition), Media Promoters & Publishers PVT. LTD
END