Hello friends, Today we are going to discuss the milling
machine, In which we will know all aspects related to the milling machine such as parts
of milling machine, types of milling machine and also covers the operation of
milling machine.
The most commonly used machine after
lathe machine is the milling machine.
It is also a type of manufacturing machine like drilling machine,
shaper machine, planer machine, etc.
Basically milling machine is used for making a flat surface, slots, splines,
keyways, sprockets, and gears.
Slots and keyways can also be made by slotting machine which I have already discussed.
What is Milling?
Milling is a method in which the material is cut by feeding the workpiece under a rotating multiple tooth cutter and producing a machined surface that may be flat, angular, or curved.The cutting action of teeth on milling cutters can be quickly machined.
Parts of Milling Machine
The main parts of the milling machine are following:- Base
- Column
- Knee
- Saddle
- Work Table
- Spindle
- Overarm
- Arbor
- Brace
- Milling Cutter
Show in figure parts of milling machine which are described below.
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| Parts of Milling Machine |
Base
It is made up of gray cast iron whose top and bottom surfaces are machined in
precision and it acts as a foundation member for all other parts of the
machine.Column
A column is a vertical member that is cast with the base.These parts of the milling machine have an all driving mechanism for spindle and table feeds.
Its front vertical face is machined in precision and the top of the column is finished to hold the overarm.
Knee
It is a strong casting of gray cast iron that slides up and down on the vertical wedge of the column.It consists of a table feed mechanism and various controls.
A knee is used to support saddles, work tables, and workpiece clamping devices.
Saddle
The top of the knee is fitted with a saddle, which slides on the face of the column on the guideways set at exactly 90°.The top of the saddle is machined in precision to provide guideways for the table.
Work Table
A work table is the most important part of a milling machine on which the workpiece or a job holds tightly and performs many operations.The top of the table is finished in precision and 'T' slots are made to clamp the work and other fixtures.
Spindle
The spindle is located at the top of the column and rotates through receives power from belts, gears, and clutches and transmits it to the arbor.Overarm
It is mounted at the top of the column and rises in front of the column face.It is commonly used to support arbor and spindle.
Arbor
It is the extension parts of spindles on which milling cutters are held or rotated.Brace
A brace is an additional support that is fitted between the knee and the overarm to ensure greater strength for the arm and knee.Milling Cutter
It is the very most important part of a milling machine because through milling cutters different types of milling operations are performed.It is a multipoint cutting tool in a milling machine.
Types of Milling Machine
There are following types of milling machines are used:- Column and Knee Type
- Fixed Bed Type
- Planner Type
- Special Type
Column and Knee Type
Above shown in the figure the milling machines are the column and knee types.
Column and knee type milling machines can be classified into
three categories.
- Plane/Horizontal Milling Machine
- Vertical Milling Machine
- Universal Milling Machine.
Plain/Horizontal Milling Machine
It is stronger than many other types of milling machines.In these types of milling machines, the table can be fed in three directions longitudinal, vertical and crosswise.
Vertical Milling Machine
The vertical milling machine differs from the horizontal milling machine according to the spindle's position because Its spindle rotates on the vertical axis.Universal Milling Machine
A universal milling machine is similar in shape to a plane milling machine.But in addition to the movement in three directions, the table can be swiveled in the horizontal axis as well.
All types of milling work can be done on these types of milling machines.
It is used for cutting helical gears, different types of straight and taped works, etc.
Fixed Bed Type Milling Machine
It is very heavy, and its table is directly tied on the fixed bed wedge.Its table can reciprocate at right angles along the axis of the spindle.
There is no system for a cross or vertical adjustment.
In these types of milling machines, the milling cutter is mounted at the spindle head which can move vertically on the column and the spindle also can be adjusted horizontally to provide cross adjustment.
Planer Type Milling Machine (Plano - Miller)
It is large in shape and is used for heavy duty work.Spindle heads can be adjusted vertically and in transverse directions.
Special Type Milling Machine
There are following special types of milling machines are used:- Surface Milling Machine
- Thread Milling Machine
- Gear Milling Machine
- Copy Milling Machine
Surface Milling Machine
This milling machine is used for multi-production work.Its spindle head can be adjusted vertically with a milling cutter.
In these types of milling machines, the feed movement is given by the table.
Thread Milling Machine
A thread milling machine is used for the milling of threads.Gear Milling Machine
A gear milling machine is used for the milling of different types of gear.Gear teeth are often cut by milling with the help of a dividing head.
Milling of small gears can be also done on a horizontal milling machine but special gear machines are required for milling larger gears.
Copy Milling Machine
It is used to make workpieces that have irregular surfaces.Work Holding Devices for Milling Machine
There is the following work holding devices often used to hold the work on the table of the milling machine.- 'T' bolts and clamps
- Angle plates
- 'V' blocks
- Vices
- Special fixtures
You can also read Work holding devices in lathe machine which I have talked about in the previous post.
Now we will discuss the operation of the milling machine,
But before knowing this first of all I suggest you read the types of milling cutters and their uses which I have already discussed so that we can better understand the operation of the milling machine.
Operation of Milling Machine
The commonly used milling operations are described below.- Plain Milling
- Face Milling
- Side Milling
- Straddle Milling
- Angular Milling
- Gang milling
- Form Milling
- Profile Milling
- End Milling
- Saw Milling
- Milling of Keyways, Grooves, Slots
- Gear Cutting
- Helical Milling
- Cam Milling
- Thread Milling
Show in figure operation of milling machine,
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| Operation of Milling Machine |
Plain Milling
Plain milling is an operation of a milling machine in which a plane, the flat horizontal surface is drawn parallel to the axis of rotation of the plane milling cutter.This is also called slab milling.
Face Milling
These types of milling operations are done by a face milling cutter which rotates in the vertical direction along the axis of the work surface.
Side Milling
Side milling is an operation of a milling machine in which the flat surface is made on the side of the workpiece using a side milling cutter.Straddle Milling
Straddle milling is an operation of a milling machine in which flat vertical surfaces are made on both sides of the workpiece using two side milling cutters tied on the same arbor.Angular Milling
Angular milling is an operation of a milling machine in which the angular surface is formed on the workpiece at an angle other than the right angle along the axis of the spindle of the milling machine.Now, See in figure gang milling, form milling, end milling, saw milling operations which are described below.
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| Operation of Milling Machine |
Gang milling
A gang milling is a type of milling operation in which several surfaces are
machined on the workpiece, using one diameter or different diameter cutters
together on the machine arbor.Form Milling
Form milling is a type of milling operation in which irregular contours are made using form cutters.Irregular contours that can be convex, concave, or any other shape.
Profile Milling
This is an operation in which a complex-shaped outline of a template or master die is created on a workpiece.End Milling
End milling is an operation in which a flat surface is made which can be vertical, horizontal, or at any angle.
Saw Milling
Saw milling is a type of milling operation in which narrow slots or grooves
are made on the workpiece using a saw milling cutter.Milling of Keyways, Grooves, Slots
Keyways, grooves, and slots can be made on a milling machine using a plane milling cutter, slitting saw, end mill, or side milling cutter.Gear Cutting
Gear cutting can be done on a milling machine using a form relieve cutter.The cutter can be of the cylindrical type or end mill type.
Helical Milling
Helical milling is an operation of a milling machine in which helical flutes or grooves are made at the periphery of cylindrical or conical workpieces.Cam Milling
Cam milling is a type of milling operation in which the cams are made on a milling machine using a universal dividing head and vertical milling attachment.Thread Milling
Thread milling is an operation of a milling machine in which threads are made using a single or multiple thread milling cutter.This operation is performed on a special thread milling machine to make small or large quantities of precision threads.
So friends here I discussed parts of milling machine, types of milling machine and as well as operation of milling machine.
I hope you all clearly understand all aspects related to this topic.
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