The lathe machine is one of the most essential machining tools in the manufacturing industry. It facilitates a variety of operations, including facing, turning, knurling, and cutting. It is among the first machining tools, and its origins can be traced back to Ancient Egypt.
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 get started!
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.
Screw threads or helixes, flat surfaces, and the majority of solids of revolution may all be produced with the most appropriately outfitted metalworking lathes. 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 great advantages to their operations. It is used in woodturning, metalworking, thermal spraying, metal spinning, glassworking, and parts reclamation. lathe application also includes pottery shaping, best known as potter’s wheel.
Metalworking is popularly known for the use of lathe machines, as various operations can be accomplished. These operations include cutting, sanding, drilling, facing, knurling, turning, and deformation. Some important applications of a lathe machine include:
- Lathe can be used to create rounded or partially rounded pieces.
- Both male and female threads can be cut using it.
- Lathe can be used for cut-off material.
- A lathe machine is used to drill and bore holes or to knurl knobs.
- Taper a shaft and polish a rounded part’s surface.
- Rough stock should be faced or dressed.
- Lathe can also be used to mill small pieces.
Related: What is Electrochemical Grinding (ECG)? Its Parts & How it Works
Parts Of A Lathe Machine
A lathe machine consists of several essential 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
The headstock gives the rotating power for the lathe’s operations once it is clamped to the end. 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 increases the efficiency and output per cycle. It’s interesting to note that the mechanism known as the “second spindle” has the same capacity and power as the primary spindle.
Guide Way
It is what enables smooth cutting by allowing the tool to move both vertically and horizontally.
Chuck
A chuck secures the pieces for machining. It is fixed to the main spindle that turns 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 very small machine, mostly used by wristwatch manufacturers. It is mounted on a cabinet or bench and used for small and precise work that requires high accuracy. It contains all parts the larger lathe carries and will perform almost the same operation as the larger ones.
Speed lathes
These types of lathe machines are used in 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. As a result, feeding and activating the tool are both done by hand. As the name implies, speed lathes are named because of the very high speed at which the spindle rotates.
Engine Lathe
engine lathe is one of the most used lathes. The name is quite confusing, 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. Because of this, it is a popularly known engine lathe today.
Practically, these lathe machine types look like a speed lathe as it has 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, making it have a cone pulley with back gears. This helps to provide desired speed to the headstock spindle, which is why the machine is also called geared head lathe.
Toolroom Lathe
These types of lathe machines are the same as the engine lathe but have some extra features. One of these features is to make it suitable for a relatively more accurate angle of speeds and feeds. However, the ideal features of the tool room 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
These types of lathes are widely used in mass production and it’s very important due to their features. They are actually semi-automatic, and various operations can be performed on them. Little skill is required to operate the machine; the only skills required are in the tools set in the turret or capstan head. Once this setting is successfully done, the operations are done automatically.
Automatic lathe
An automatic lathe is known for its enhancement in quality and quantity of production. This machine is so perfect that the complete manufacturing process is automatically achieved. This means no participation of the operator is required during the operation.
And just like the semi-automatic lathes, the work of operators is just the mounting and removing of workpieces from the spindles. Well, automatic types of lathe machines are available with single or multi spindles. They are classified as heavy-duty, high-speed lathes mainly used for mass production.
Lathe Machine Operations
The various lathe operations are turning, facing, grooving, parting, threading, drilling, boring, knurling, and tapping.
Turning
Turning is the most popular kind of lathe operation, which is achieved by removing material from the outer diameter of a workpiece. It is often done on at the begining of the machining before other operation 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.
The rough operations are performed to a piece within a predifined thickness, by removing the maximum amount of material in the shortest possible time. During this, accuracy and surface finish is disregarded. While finish 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 trasition between the surfaces with two different diameters can have several features such as step, chamfer, taper, and contour. The diagram below shows the different types of turning:
- Step turning is used creates 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 the step turning, chamfer turning creates 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 is 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 perpendicualar to the rotating axis.
During the operation, the cutting tool moves along the radious of the workpiece to produce the desired part length and a smooth surface must be acomplish as the final process.
Grooving
Grooving is a kind of turning operation that is performed to create a narrow cut “groove” in the workpiece. The width of a cutting tool will determine the size of the cut. While wider grooves might require 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, 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 in perpendicular to the rotating axis and make a progressive cut while the workpiece rotates.
The workpiece drop off as soon as the cutting tool edge reaches the centre of the workpeice. Sometimes, part catcher is used to catch the removed part.
Threading
These turning operation that is done by cutting thread in the outer surface of a workpiece. The tool moves along the side of the workpiece, and the thread is uniform helical groove of specified length and pitch. Deeper thread 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. This knurls have teeth that are rolled against the surface of the workpiece forming a serrated patterns. Diamond pattern is the most common.
Drilling
Drilling is a popular operation that can also be performed on lathe. It is achieved by using a drill bit to remove the 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 remvoe a minimal amount of material and create accurate diameter and a smoother internal finish.
Boring
Boring is a turning operation that is achieved as the cuttng tool enters the workpiece axially and removes material along the internal surface. It is performed to either create different shapes or to enlarge an existing hole like that of reaming.
Tapping
Tapping is achieved by using a tapping tool to cut threads into an existing hole. The tapping tool enters the workpiece axially and cuts the thread. The hole is the size of the tap bit so that will accommodate the tapping tool. These 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, facing operation is done as less force is applied via the cutting tool. Work can also be done at a right angle to the axis of rotation. An eccentric turning or multi-axis turning can be achieved when a workpiece is mounted with a certain axis of rotation.
When it’s then remounted with a new axis of rotation, resulting to various cross-sections of the workpiece being rotationally symmetric. However, the workpiece is not rotationally symmetric. The tool post firmly holds cutting tools toward the revolving workpiece, which helps to achieve the desired cut.
Related: What is NC Machining? its Types and How it Works
Advantages of Lathe Machine
- When comparing CNC lathes to normal machining lathes, the precision is significantly higher.
- There is a high speed of production.
- Not need very experienced operators.
- complete automation, which makes work easier and faster.
- Both the lathe and the CNC lathe machined fairly quickly.
- Extremely adaptable, enabling usage in the production of various parts and products.
Disadvantages of Lathe Machine
- Poor maintenance would result in the machine’s parts being damaged by not utilizing lubricant.
- if the user is not competent enough to do the experiment, the equipment quickly wears out.
- The smell will be strong in the air due to the bite’s rapidity, which has an impact on health.
- Given that a lathe can do practically any operation, these machines can be more expensive 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.
- When the machine is operating, adjustments should not be made.
- 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?
A lathe is a type of machining tool that is mainly used 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 the workpiece 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.