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Accessories and Attachments of Lathe Machine

Accessories and attachments of lathe machines are essential components that enhance the versatility
and functionality of the machine. These carefully crafted add-ons are designed to expand the
capabilities of the lathe, enabling it to perform a wide range of precision tasks with precision and
efficiency. Whether it's shaping, cutting, drilling, or threading, these accessories and attachments
empower machinists to achieve intricate and complex machining operations while ensuring the highest
level of accuracy and precision.

What is a Lathe Machine?

A lathe machine is a precision machine that secures a workpiece using a chuck and positions a cutting
tool on a toolpost. It operates by rotating the workpiece along a central axis, facilitating a wide array of
lathe operations. These operations encompass tasks such as turning, facing, chamfering, thread cutting,
knurling, drilling, and numerous others. Utilising various cutting tools applied to the workpiece, a lathe
machine meticulously crafts objects, ensuring symmetry about the axis of rotation.

Accessories of Lathe Machine

The following are the different lathe accessories:

Centres

Chuck

Catch plate or carriage

Face plate

Angle plate

Mandrel

Rests

Centres
Centres: In lathe machining, Centers are essential components used to support and accurately align the
workpiece, enabling precise turning, facing, and tapering operations. They provide stability and
rotational symmetry to the workpiece during the machining process.

Ordinary Centre

An ordinary centre is a versatile option for general machining and smaller operations. It provides a
stable point of support for the workpiece during lathe operations.

Tipped Centre

The tipped centre stands out among all centre types due to its crucial role. It features a tip made from
hard materials that exhibit exceptional deflection, wear, and tear resistance, ensuring precision and
longevity in machining tasks.

Ball Centre

Specifically designed for taper turning using the set-over method, the ball centre minimises wear and
strain on the workpiece. Its rounded shape facilitates smoother and more precise taper turning.

Insert Type Centre

Recognised for its cost-effective design, the insert type centre allows for the replacement of only the
high-speed steel "insert" rather than the entire centre. This feature makes it an economical choice for
machining operations.

Half Centre

Similar to the ordinary centre but with a portion of its centre ground away, the half centre provides
stability while accommodating workpieces with specific requirements, allowing for greater versatility in
machining tasks.

Pipe Centre

Pipe centres are commonly used in production works to support the open ends of pipes. They offer
reliable support and alignment for cylindrical workpieces, particularly in scenarios involving pipes.
Frictionless Centre

Typically found in the tailstock, the frictionless centre boasts the capability to withstand high-applied
forces while allowing rotation along with the workpiece. Its ability to operate at very high speeds makes
it ideal for demanding machining applications.

Chucks

Chucks are generally used to support and hold the workpiece in order to carry out different operations
in the lathe. The different types of chucks are as follows.

3 jaw universal chuck

4 jaw independent chuck

Combination chuck

Magnetic chuck

Collet chuck

3 Jaw Universal Chuck

lathe machine

Fig 3: Three Jaw Lathe Chuck

The 3 Jaw Universal Chuck is equipped with three high-quality steel jaws arranged at an angle of 120° to
each other. These jaws engage with spiral teeth (known as Bevel's teeth) during operation. The
interaction with these teeth, facilitated by a bevel pinion rotated using a square-end key, commonly
referred to as the "chuck key," causes a simultaneous movement of all three jaws either towards or
away from the centre of the chuck. Due to its excellent gripping capabilities, this chuck type is primarily
employed for securing workpieces with circular or hexagonal shapes.

4 Jaw Independent Chuck

The 4 Jaw Independent Chuck features four jaws positioned at 90° angles to one another. Unlike the 3
jaw chuck, each of these four jaws can be operated independently using individual screws, eliminating
the need for a scroll disk. This design makes it ideal for securely holding irregularly shaped workpieces
that may not align well with the standard chuck configurations.

Combination Chuck

The Combination Chuck combines the functionalities of both the universal chuck and the independent
chuck. It is a versatile chuck type that can serve as either a self-centering chuck or an independent
chuck, offering flexibility in machining operations. This chuck incorporates independent screws and a
scroll disk, allowing the user to choose between moving the jaws separately by manipulating the screws
or simultaneously using the scroll disk. Consequently, it is suitable for securing both regularly and
irregularly shaped workpieces, offering adaptability in various machining scenarios.

Catch Plates or Carriers

Catch plates and carriers play a vital role in driving workpieces when they are held between two centres
on a lathe. Carriers are essentially driving dogs that attach to the end of the workpiece using a setscrew,
while catch plates are bolted to the nose of the lathe's headstock spindle. Both feature projecting pins
that fit into corresponding slots. A single-pin catch plate drives the straight end or tail of the attached
carrier, while double-pin catch plates engage with double-tail or double-slotted carriers, providing
uniform drive. Bent-tail types are used in conjunction with a faceplate or slotted catch plate.

Face Plate

A circular plate threaded at its centre with plain and T-slots, the faceplate is affixed to the lathe spindle's
central threaded portion. It secures the workpiece using bolts and clamps within its slots. The faceplate
is versatile, accommodating both regular and irregularly shaped workpieces that chucks or centres may
not easily hold. This makes it a valuable tool for various machining tasks.

Angle Plate

Made of cast iron, the angle plate boasts two precisely machined faces set at a right angle to each other.
It features holes and slots on both faces for clamping onto a faceplate and securing workpieces with
bolts and clamps. Angle plates are particularly useful when the holding surface of the workpiece must
remain horizontal, as is often the case in tasks such as machining a pipe elbow's flange. A balance weight
or counterweight may be necessary for eccentric jobs attached to the faceplate.

Mandrels

Mandrels are essential for holding rotating workpieces that have been previously drilled, stepped,
turned, or bored, allowing for further machining operations. Various types of mandrels are available to
suit specific workpiece requirements, including plain mandrels for parts with plain surfaces, step
mandrels for workpieces with stepped inner portions, cone mandrels for conical workpieces, screw
mandrels for threaded workpieces, and gang mandrels with fixed and movable collars for holding sets of
hollow workpieces.

Rests

Rests serve as support structures in the lathe to prevent the bending of long workpieces due to their
own weight and vibrations. Positioned between the lathe's centres, they are essential when the
workpiece's length is significantly longer than its diameter.

Steady Rest

Comprising a cast-iron structure with a machined base, the steady rest can be clamped like a tailstock in
various positions between the lathe's centres to support and hold the workpiece. Its upper semicircular
body is hinged, allowing for movement without removing the rest completely. Equipped with three
screw-type jaws at 120° intervals, these jaws can be adjusted radially to provide support. Multiple
steady rests may be used for exceptionally long workpieces.

Follower Rest

The follower rest is a C-shaped cast iron structure with two adjustable jaws affixed to the lathe carriage,
moving in tandem with it. Its purpose is to prevent deflection of the workpiece during cutting
operations. Initially, a portion of the workpiece is machined, and the follower rest is adjusted to provide
bearing support. The tool is positioned slightly ahead of the jaws to ensure continuous support on the
machined surface, making it ideal for finishing turning operations.