In this topic you will learn all aspects related to milling machines like their working principle, types and uses.
Milling machine is used in a manufacturing process in which many types of operations are done with the help of a multi-point cutting tool called a milling cutter.
This machine is also used for cutting gear teeth through indexing in milling machines.
Working Principle of Milling Machine
In the milling machine job or workpieces are clamped generally to the table to perform any work on the milling machine.
Therefore, when the workpiece or a job comes in contact with the cutter, the teeth of the cutter cut the metal in the form of chips.
The job on the table can be fed in all three directions in Longitudinal, Crosswise and Vertical in height.
Types of Milling Machines
The following types of milling machines are used.
- Column and knee type milling machine
- Fixed Bed Type Milling Machine
- Planer Type Milling Machine
- Special Purpose Milling Machine
Column and Knee Type Milling Machine
This type of milling machine is most often used in the machine shop.
The table of this machine is kept on the knee which can be raised up and down at different heights anywhere, the mechanism to give different movements to the table is also fitted in this part.
There are following types of column and knee type milling machines are used.
- Hand Milling Machine
- Plain Milling Machine
- Universal Milling Machine
- Omniversal Milling Machine
- Vertical Milling Machine
- Ram Type Milling Machine
Hand Milling Machine
This type of milling machine is a one of the machines which is used to perform small and simple operations.
All the feed and speeds of this machine are given by hand.
This machine is especially useful for cutting small slots, keyways, and grooves.
Plain Milling Machine
This machine is stronger and larger in size as compared to the hand milling machine.
The speed of this machine can be given both manually and automatically.
Universal Milling Machine
This machine is also like a plain milling machine.
But the difference is that the table of this machine can be set anywhere between 0° to 45° by rotating left, right.
The working capacity of this machine has been increased by many attachments.
This machine is generally used in the tool room.
Omniversal Milling Machine
Compared to the table of the universal milling machine, the table of this machine can be tied in the vertical plane by rotating it at any angle, thus the table of these machines can be given relatively more speed.
Vertical Milling Machine
The direction of spindle of this machine is vertical and the spindle head can be clamped by rotating it at any angle from 0° to 90° on both the sides.
The spindle of this machine can also be raised and lowered like a drilling machine.
Drills, End Mills, Shell End Mills, Facing Cutters and similar shank cutters can also be clamped on this machine.
Ram Type Milling Machine
In this type of machine, the work table is fitted over the vertical side passages above the column with the help of nut bolts on the saddle.
There is also a provision for up and down movement.
Fixed Bed Type Milling Machine
Due to the fixed bed of these machines, heavy cuts can be made on them.
These machines have a vertical column, On which paths are made for the spindle head to move.
This machine is very heavy so it is fixed at a one place.
These machines are classified as follows.
- Simplex Milling Machine
- Duplex Milling Machine
- Triplex Milling Machine
Simplex Milling Machine
In this machine there is only one spindle head in which the cutter is caught by applying arbour.
This spindle head can be moved up or down on the column depending on the height of the work or a job.
Duplex Milling Machine
This machine has two separate cutter heads.
These cutter heads are adjusted by sliding up and down on the two columns fitted on the sides of the bed.
These cutter heads can be used together or separately.
Thus two planes can be machined simultaneously on this machine.
Triplex Milling Machine
Two cutter heads are fitted in a triplex milling machine similar to a duplex milling machine and the third cutter head is mounted on a cross-rail.
This cutter head can be operated at different speeds for cutting.
These cutter heads can be moved quickly from one place to another for cutting operations.
The cutting process is done continuously by these machines in a sequential manner.
In which it is easy to do the same type of work.
Planer Type Milling Machine
This machine is designed for the machining of very heavy work and large size floors.
This is a heavy machine.
On the cross-rail of this machine, instead of the tool head, the cutter head is installed.
The height of the cross-rail can be adjusted anywhere up or down on the housing according to the working height.
Special Purpose Milling Machine
These machines are made for a specific purpose.
All the parts manufactured by them are made in the same shape and size, due to which interchangeability remains in the parts.
These machines are classified according to the function.
- Rotary table milling machine
- Profiling Machine
- Planetary Milling Machine
- Pantograph Milling Machine
- Drum type Milling Machine
- Tracer Controlled Milling Machine
- Gear Hobbing Machine
- Thread Milling Machine
Rotary table milling machine
The table of this machine is round in shape and more than one cutter can be used on this machine.
This machine is generally used for the facing process.
This machine is similar to a bed type vertical milling machine.
In which the spindle can be moved up and down and back and forth in the recumbent plane.
This machine is specially used to make a special die or tool.
Planetary Milling Machine
In this machine, the work remains constant and both the cutting or feed movements are given to the cutter itself, that is, the cutter moves around the job like a planetary path and moves simultaneously.
On this machine both external and internal round planes can be manufactured separately or together.
Generally this machine is used for cutting internal and external threads of different pitch.
Pantograph Milling Machine
This type of milling machine is available in two or three dimensional pantograph models.
A pantograph is a device that consists of four rods or links and lives in the shape of a parallelogram.
With the help of this mechanism, according to the shape of the model, the size of the figure on the job can be made by reducing or increasing the size in proportion.
This machine is often specially used for engraving.
Drum type Milling Machine
The table of this machine, which is called a drum, rotates under four spindles simultaneously in a circular motion.
On which, after completing one revolution of the drum, the machined parts are taken out and replaced by new parts.
Tracer Controlled Milling Machine
This machine is used for manufacturing special types of planes in die and moulds.
Whether those planes are regular or irregular, the feed is controlled by a special method called servo-mechanism.
Gear Hobbing Machine
In this milling machine a hob cutter is used for cutting teeth.
In this way, many gears can be cut at a time.
Thread Milling Machine
This machine is used for cutting acme or worm gear teeth, etc.
My name is Kamal Dwivedi & I am a founder Mechical where people learn all about mechanical engineering.
I am an Engineer (Mechanical Engineer) by profession and also working in the Power and Manufacturing Industry for the last 10 years.
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