The lathe machine is a mechanical tool or device that is commonly used in heavy industry. It operated through a swarf removal process for cutting purposes, shaping of materials, and polishing of different parts made with different materials.
There are different types of lathe machines, and each has its own function, such as milling, turning, and automatic. These machines are also defined based on tabletop and benchtop lathes.
In this post, we will cover details and features for different parts of the lathe machine. So, let’s get started with
What is a Lathe Machine?
A lathe machine is a flexible tool that is utilized to shape and cut different materials, like metal, wood, and plastics. It is a sort of mechanical device that rotates the workpiece on its axis, permitting the cutting tool to move along and eliminate material to create the ideal shape.
Lathe Machines can be operated manually or utilizing computer numerical control (CNC) technology, and they come in a range of sizes and designs to suit various applications.
They are generally utilized in manufacturing and machining industries for producing parts with exact dimensions and complex shapes. The Parts of a lathe machine incorporate the bed, tailstock, headstock, carriage, tool post, and many more parts, which have their own particular elements and benefits.
Parts of the Lathe Machine
#1. Lathe Bed.
The lathe bed is the rigid and robust part of the lathe machine. It is generally made of cast iron because it is hard and absorbs vibrations. It avoids deflection due to a heavy working load.
The headstock is located on the left side, and the tailstock is on the right side of the bed. The carriage rests on the bed and slides over the bed.
On top of the lathe bed, guideways are there to slide the tailstock and carriage over it.
These guideways are accurately machined to make them parallel with each other and provide bearing and sliding surfaces for the tailstock and carriage to slide. It is high resistance to wear.
There are two types of guideways.
- Flat guideways
- Inverted V guideways
Flat guideways give a high bearing surface, minimum wear, and are easy to clean. Inverted V guideways offer better alignment and a better guide to the tailstock and carriage. It helps to fall the chips from the bed.
#2. Headstock.
The headstock is the main component of the lathe machine, which is called the powerhouse. It lies on the left of the bed and comes with a spindle and motor that control the working component rotation. The headstock is used for providing power and the required speed for machining functions.
The headstock is used for holding and rotating the working component at different speeds, based on the materials and work needed. It is important for defining spindle speed that has an effect on the accuracy of the machining process.
The spindle of the headstock gets power from the motor. When the motor operates, it provides power to the spindle; as a result, it rotates. Different parts like chucks, faceplates, or collets are configured on a spindle that firmly controls and holds the working component in position during working.
For an accurate working headstock, there is a need for proper speed features, and make sure the spindle is accurately aligned. Material hardness and cutting type are needed to affect the speed at which the headstock operates.
#3. Spindle.
The material of the spindle is nickel or carbon chrome steel. The centreline of the spindle and the centreline of the lathe are perfectly in alignment with each other.
It is hollow from the inside. So, a long bar can pass through it. The front end of the spindle can hold the taper part.
There are two types of spindles.
- Threaded
- Flanged
The threaded design carries a driving plate, faceplate, and chuck, whereas a flanged one enables them to attach.
The spindle is required with two bearings in the headstock from both sides. It can be a ball, bush, or roller bearing, and its selection depends on the type of application, loads, speed, and accuracy.
#4. Chuck.
Chuck is for holding the workpiece during the machining process. It can be able to hold workpieces of irregular shapes rigidly and quickly.
Chuck is attached to the backplate with a bolt, and the backplate is screwed to the spindle nose. It is necessary to have an accurate alignment of the chuck with the lathe axis.
Different types of chucks
Four-Jaw Chuck
Four jaw chuck has four jaws that slide in the slot to give good gripping for different shapes of workpieces. In some cases, each jaw can slide independently by rotating a screw.
With the chuck, we can clamp hollow parts from the inside and outside. The gripping surfaces of four jaws simultaneously apply pressure on the outside diameter of the pipe for clamping.
Whereas, for clamping from the inside, outer gripping surfaces simultaneously apply pressure on the inside surfaces of the pipe.
Three-Jaw Universal Chuck
A universal chuck consists of three jaws that simultaneously slide in the slot to clamp the workpieces. We can reduce the distance between the three jaws by rotating the key in the chuck slot.
This chuck is suitable for delivering a quick grip in round, hexagonal, and similar shapes. It has less gripping capacity than four jaw chuck.
Air or Hydraulic operated Chuck
It consists of a hydraulic or compressed air cylinder mounted on the backside of the headstock. During the clamping act, hydraulic oil or compressed air is forced through the valves to the cylinders.
So, the piston slides into the cylinder, and these pistons connect to the jaws to open and close.
Magnetic Chuck
These chucks are suitable for only ferrous metals. This type of chuck is appropriate for those metals that cannot sustain the pressure applied by the jaws of other types of chucks.
In most cases, an electromagnet is present to make a magnetic force to clamp the workpiece. When we switch ON the power, flux develops to create a magnetic force.
During the removal of the workpiece, we can switch OFF the power. By using ‘keepers’, we can short the circuit and prevent the flux from passing through the workpiece.
Collet Chuck
It is suitable for holding long parts. These parts pass through the spindle and are attached to the collet from the front end of the spindle.
The shape of the collection is round, hexagonal, etc trusting on the type of workpiece. Collet has an external thread lengthwise.
During the fixing of the collet into the spindle, a key is inserted in the chuck hole to engage the thread with the collet to get better fixing. By loosening the key, we can disengage the collet.
Combination Chuck
It is a combination of four jaw chuck and a universal chuck. We can drag their jaws independently, or, through some adjustment, we can move their jaws simultaneously.
Drill Chuck
It is used for holding shank drills or taps for respective operations.
#5. Tailstock.
The tailstock exists opposite to the headstock, and this part is used for providing some support for the working component at the time of functions. It has moving features over the bed and handles working components at different lengths.
The tailstock provides stability for the working component for longer machining operations. It is also configured with a drill chuck for boring functions.
The tailstock moves over the bed and locks in the required position for handling the working component. If the drill process required the quill to be extended for driving the drill bit into materials
For working of the tailstock, there is a setting needed over the bed for alignment of the spindle. After that, the tailstock locks and gives support for the stable rotation of the working component.
#6. Carriage.
The carriage is the main part of the lathe machine, used for holding and moving cutting tools. It moves over the bed that provides accurate cutting, drilling, and working component shaping.
The carriage holds cutting tools and moves over the surface of the working component to provide proper machining function. Its main workings are turning, facing, and threading.
The basic working of the carriage is to move longitudinally through the handwheel or lead screw. The cross-slide component of the carriage moves the cutting tool at 90 degrees to the working component. This type of motion helps to make different shapes of components and cut at different angles.
#7. Saddle.
The saddle is an H-shaped casting that fits the bed and slides along the guideways. The Cross slide and tool post are part of the saddle.
#8. Cross Slide.
A cross slide is provided at the top of the saddle where a male dovetail is assembled, with a female dovetail on the other side. The cross slide top surface is furnished with T-slots to empower or engage the fixing of the rear tool post or coolant connection.
The carriage fundamentally provides a mounted or automatic cross-movement for the cutting tool.
#9. Compound rest.
The compound rest mounts on the cross slide, which has a circular dial for angle. Its function is to arrange compound rest at a specific degree to achieve cuts in angles and tapers.
With the compound rest handle, we can give motion. It is a manual operation to do. The compound rest handle has a micrometer guide to decide the depth of the cut.
#10. Tool post.
At compound rest, the tool post is mounted. Holding different cutting tool holders is utilized. Wedge which is shaped, formed, and molded on the base to fit into a concave-shaped ring on the holder’s rest, which permits the height of the cutting edge to be changed by tilting the tool.
It is fixed on the top slide. By the movement of the seat, cross slide, and top slide tool post gets its movement.
The three kinds of tool posts that are generally utilized are:
- Ring and rocker tool post: It includes a roundabout tool post with a slot attached for accommodating the tool.
- Quick-change tool post
- Square head tool post.
#11. Apron.
The apron contains gears, levers, clutches, etc., in the operation of the carriage. It plays a primary role in automatic feeds.
By employing the split nut with the lead screw, we can construct internal or external threads on the object. The handwheel of the apron helps to move the carriage forth and back.
#12. Motor.
It is the power source of the lathe machine. When the motor turns ON, it transfers the rotating motion through a belt drive, chain drive, or gear drive to the headstock spindle.
Due to that chuck rotates at a specific speed.
#13. Lead Screw.
The feature of the screw is to align different threads through the bend. For smoothing other refinements with working components, a smooth screw gets the screw position.
The lead screw is important for threading or for providing automatic feeding for longer cuts.
The lead screw is regulated with the headstock and rotates through the spindle. that turns the carriage over the bed that provides threading and feeding with high accuracy.
When you set the required parameters, operators adjust the lead screw, and the carriage moves to cut threads with smooth accuracy over the working component.
#14. Feed Rod.
The feed rod helps to transfer motion from the lathe spindle to the apron assembly by the feed rod. There are so many gear arrangements there to transmit movement.
Feed rods help during turning, facing, and all other operations on the lathe machine by giving motion to the carriage.
#15. Thread-cutting mechanism.
This mechanism operates by the half-nut mechanism. This mechanism engages or disengages the carriage with the lead screw. The closing of the half nut allows the carriage to move at a fixed distance.
A split nut is used only during thread cutting, not for other operations.
#16. Chip Pan.
It is for collecting chip formations during various operations on the lathe machine. It is at the base of the lathe machine.
#17. Gearbox.
It is present inside the headstock. It offers variation in speed with a geometric ratio as per requirement by moving a lever.
#18. Cooling Devices.
During the operations on the lathe machine, a cooling agent is necessary to reduce heat formation. The cooling water pump sprays the cooling medium during the process to reduce heat and remove chips from the working area into the chip pan.
#19. Legs.
On the leg, the whole mass of the machine is balanced. These legs are bolted to the foundation with bolts to transfer machine vibrations to the ground. It is crucial to pass a certain amount of machine vibrations to the earth for better stability.
#20. Apron.
The apron is part of the carriage that houses the control mechanisms. It contains gears, clutches, and levers used to control the movement of the carriage and the cross slide.
The apron is essential for the operator to control and adjust the carriage’s position and motion during machining operations.