What Is A Lathe Machine? Its Diagram, Parts and How it Works

The lathe machine is one of the most essential machining tools in the manufacturing industry. It facilitates various operations, including facing, turning, knurling, and cutting. Ancient Egypt is the origin of one of the first machining tools.

In this reading, we’ll explore what a lathe machine is, its diagram, application, parts, types, and how it works. We’ll also learn its advantages, disadvantages, and safety precautions.

Let’s begin!

What Is A Lathe Machine?

A lathe is a type of machine tool that uses tools applied to the workpiece to achieve various kinds of operations, including cutting, grinding, knurling, drilling, deforming, facing, and turning to create an object with symmetry around this axis.

The most appropriately outfitted metalworking lathes can produce screw threads or helixes, flat surfaces, and the majority of solids of revolution.

Lathes are employed in glass processing, metalworking, woodturning, thermal spraying, and parts reclamation. Pottery can be shaped with lathes; the potter’s wheel is the most recognized design.

Using ornamental lathes, one may construct extremely complex three-dimensional bodies. The workpiece is usually held in place by one or two centers, at least one of which can be adjusted horizontally to accommodate different workpiece lengths.

Applications Of Lathe Machine

The applications of lathe machines are broad, as they offer numerous advantages to their operations.

Lathe machines find application in woodturning, metalworking, thermal spraying, metal spinning, glassworking, and parts reclamation. lathe application also includes pottery shaping, best known as the potter’s wheel.

Lathe machines are popular in metalworking because they can perform a variety of operations. These operations include cutting, sanding, drilling, facing, knurling, turning, and deformation. Some important applications of a lathe machine include

You can use a lathe to create rounded or partially rounded pieces.
You can use it to cut both male and female threads.
Lathes can be used for cutting off material.
You can drill and bore holes or knurl knobs with a lathe machine.
Taper a shaft and polish a rounded part’s surface.
Dress or face rough stock.
You can also use a lathe to mill small pieces.

Parts Of A Lathe Machine

A lathe machine consists of several components that work together to perform various machining operations. Here are the key parts of a lathe machine and their functions:

Bed

The bed gives the machine the rigidity, strength, and support it needs. The bed is fitted with much machine equipment, including the carriage, electric motor, spindle, chuck, and tailstock.

Headstock

Once clamped to the end, the headstock provides the rotating power for the lathe’s operations. The lathe uses these bearings to rotate the workpiece against the tool bit.

Tailstock

A tailstock’s non-rotating barrel serves multiple functions, including retaining tool bits or providing support for workpieces in motion. The tailstock is at the other end of the lathe from the headstock.

Main Spindle

The spindle and the spindle-driving system make up the main spindle. Many of the lathe’s moving components, such as the motors, gears, and chuck, are housed in the main spindle. The spindle is also mounted with the C-axis drive, which aids in material positioning.

Sub-Spindle

On a lathe, the sub-spindle completes the first and second cutting operations in tandem with the main spindle. This procedure increases the efficiency and output per cycle. It’s intriguing to note that the mechanism known as the “second spindle” has the same capacity and power as the primary spindle.

Guide Way

It enables smooth cutting by allowing the tool to move both vertically and horizontally.

Chuck

A chuck secures the pieces for machining. The main spindle fixes it, turning both the workpiece and the chuck.

Tool Turret

The turret makes it possible to swap out the cutting tools as needed. The size of the turret depends on how many and what kind of cutting tools are used.

Diagram Of A Lathe Machine

Types of Lathe Machine

The common types of lathe machines include

Bench Lathe

This is a tiny machine, mostly used by wristwatch manufacturers. Mounted on a cabinet or bench, it performs small and precise tasks that demand high accuracy. It contains all the parts the larger lathe carries and will perform almost the same operation as the larger ones.

Speed lathes

We use these types of lathe machines for wood turning, polishing, centering, and metal spinning. They’re either available with supporting legs fitted to the bed or the one mounted on a bench. It contains all features other lathes carry, but it lacks provision for power feed.

It also has no gearbox, carriage, or lead screw. Therefore, one must manually feed and activate the tool. Speed lathes get their name from the extremely high speed at which the spindle rotates, as the name suggests.

Engine Lathe

The engine lathe is one of the most used lathes. The name is perplexing, right? After all, lathes are available with a motor drive. The engine lathe, however, has a significant historical significance because a steam engine powered it in its very early days.

As a result, the engine lathe has gained widespread recognition today.

Practically, these lathe machine types look like a speed lathe, as they have all its features. But the construction of the engine lathe is bigger in size and more robust, and there is a large mechanism for providing multiple speeds to the lathe spindle.

The headstock spindle receives power from a lathe shaft through a belt, enabling it to have a cone pulley with back gears. This mechanism helps to provide the desired speed to the headstock spindle, which is why the machine is also called a geared head lathe.

Toolroom Lathe

These types of lathe machines are similar to the engine lathe but include additional features. One of these features is to make it suitable for more precise control over speeds and feeds.

However, the ideal features of the toolroom lathe include taper turning, follower rest, collets, chucks, etc. Comparatively, this lathe has a smaller bed length than the engine lathe, as the most used length is 135 to 180 cm.

Capstan and Turret Lathe

Due to their features, these types of lathes play a significant role in mass production. They are actually semi-automatic, allowing for various operations.

Little skill is required to operate the machine; the only skills required are in the tools set in the turret or capstan head. Upon successfully completing this setting, the machine automatically performs the operations.

Automatic lathe

An automatic lathe is known for its enhancement in the quality and quantity of production. This machine’s perfection allows it to automatically complete the entire manufacturing process. This means the operator’s participation is not required during the operation.

Similar to semi-automatic lathes, operators only need to mount and remove workpieces from the spindles. Automatic lathe machines are available with single or multiple spindles. Heavy-duty, high-speed lathes primarily serve mass production purposes.

Lathe Machine Operations

The various lathe operations are turning, facing, grooving, parting, threading, drilling, boring, knurling, and tapping.

Turning

The most common type of lathe operation, turning, involves removing material from a workpiece’s outer diameter. It is often done at the beginning of the machining before other operations will be performed.

The main purpose of the lathe operation is to reduce the workpiece diameter to the desired dimension, which is done in two methods, such as rough and finish.

We perform the rough operations on a piece within a predefined thickness, removing the maximum amount of material in the shortest possible time. We disregard accuracy and surface finish during this process.

While finishing, turning is done to achieve a smooth surface finish and create the final, accurate dimensions.

Also, a workpiece can have different outer dimensions and the transition between the surfaces with two different diameters can have several features, such as a step, chamfer, taper, and contour. The diagram below shows the different types of turning:

Step turning is used to create two surfaces with an abrupt change in diameters between them. The final look resembles a step.
Taper turning is performed to create a ramp transition between the two surfaces with different diameters due to the angled motion between the workpiece and a cutting tool.
This turning operation is similar to step turning; chamfer turning creates an angled transition of an otherwise square edge between two surfaces with different turned diameters.
In contour turning, the cutting tool axially follows the path with a predefined geometry. Multiple passes of a contouring tool are necessary to create desired contours in the workpiece. However, form tools can produce the same contour shape in a single pass.

Facing

For accuracy during machining, the length of the workpiece is slightly longer than the final part. Facing operation is carried out at the end of a workpiece that is perpendicular to the rotating axis.

During the operation, the cutting tool moves along the radius of the workpiece to produce the desired part length, and achieving a smooth surface is the final process.

Grooving

Grooving is a kind of turning operation that is performed to create a narrow cut, or “groove,” in the workpiece. The width of a cutting tool will determine the size of the cut. Wider grooves may necessitate multiple tool passes.

The two types of grooving operations are external and face grooving. The external grooving is achieved when a tool moves radially into the side of the workpiece and removes the material. In face grooving, the face of the workpiece is grooved.

Parting

Parting is the cutting-off at the end of a machining cycle, using a tool with a specific shape to enter the workpiece. This is done perpendicular to the rotating axis and a progressive cut is made while the workpiece rotates.

The workpiece drops off as soon as the cutting tool edge reaches the center of it. Sometimes, a part catcher is used to catch the removed part.

Threading

We perform these turning operations by severing the thread from the outer surface of the workpiece. The tool moves along the side of the workpiece, and the thread is a uniform helical groove of specified length and pitch. Deeper threads undergo multiple passes on lathe machining.

Knurling

Knurling is a special turning operation that produces serrated patterns on the surface of a workpiece. This operation is often done to increase the gripping friction and the visual appearance of the machined part.

A unique tool that consists of a single or multiple cylindrical wheels (knurls) is used to achieve the process. This unique tool can rotate inside the tool holders. The teeth of these knurls roll against the workpiece’s surface, creating a serrated pattern. Diamond pattern is the most common.

Drilling

You can also perform this popular operation on a lathe. We achieve this by using a drill bit to remove material from the inside of a workpiece. The drill bits are usually positioned on the lathe tailstock or the tool holder.

Reaming

Reaming is a kind of lathe machine operation that enlarges the hole in the workpiece after drilling. During the operations, the reamer enters the workpiece axially through the end and expands the existing hole to the diameter of the tool.

Reaming is done to remove a minimal amount of material and create an accurate diameter and a smoother internal finish.

Boring

Boring is a turning operation that is achieved as the cutting tool enters the workpiece axially and removes material along the internal surface. We perform it to either create different shapes or to enlarge an existing hole, similar to the process of reaming.

Tapping

To achieve tapping, use a tapping tool to cut threads into an existing hole. The tapping tool enters the workpiece axially and cuts the thread. The hole is sized to accommodate the tap bit. This operation is also used to make threading on nuts.

How Does A Lathe Machine Work?

A lathe machine operation involves positioning the workpiece “between centers,” or between the headstock and tailstock. Smaller lathes, which can only hold the spindle firmly, are best for working with small pieces.

In this working condition, the cutting tool applies less force, allowing for a facing operation. Work can also be done at a right angle to the axis of rotation. Mounting a workpiece with a specific axis of rotation can achieve an eccentric or multi-axis turning.

When it’s then remounted with a new axis of rotation, it results in various cross-sections of the workpiece being rotationally symmetric. However, the workpiece is not rotationally symmetric. The tool post firmly holds the cutting tools toward the revolving workpiece, which helps achieve the desired cut.

Advantages of Lathe Machine

When comparing CNC lathes to normal machining lathes, the precision is significantly higher.
There is a high speed of production.
It does not require highly experienced operators.
Complete automation makes work easier and faster.
The lathes and the CNC lathes both completed their machining tasks swiftly.
It is extremely adaptable, enabling usage in the production of various parts and products.

Disadvantages of Lathe Machine

Not using lubricant could cause damage to the machine’s parts due to poor maintenance.
If the user lacks the necessary competence to conduct the experiment, the equipment will quickly wear out.
The smell will be strong in the air due to the bite’s rapidity, which impacts your health.
Lathes can perform many operations, making them pricier than other traditional machines.

Lathe Machine Safety Precautions

To keep the operator, the work, and the machine safe, there are certain safety precautions that one must understand and adhere to when using a lathe machine.

Clean up chips with a brush, not your hands.
Use a holding device to support the workpiece; do not use your hands.
Make no adjustments while the machine is running.
Do not measure on revolving parts
Use Google to avoid flying chips from entering the eye
Ensure all machine parts are securely tight
Avoid flying cloth or loose cloth
Tools should not be placed on the drilling table

FAQs

What is the use of a lathe?

The primary purpose of a lathe is to shape wood or metal. The process rotates the workpiece around a cutting tool that is stationary. The main aim is to remove material that is not required, leaving behind a well-shaped workpiece.

What is the function of a lathe?

A lathe is a type of machine tool used to form metal or wooden objects. By rotating a wooden or metal component around an axis, it provides the workpiece, while a stationary cutting tool continuously removes material from it to achieve the required shape.

Is operating a lathe easy?

Lathes, in spite of their appearance, work on basic principles. Any newbie can begin working on simple projects with all the knowledge they need if they understand a few basic ideas.

What is the most typical operation on a lathe?

Turning, facing, grooving, parting, threading, drilling, boring, knurling, and tapping are the most frequently performed lathe operations.

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