In this article, we are going to discuss about Main Parts of the Lathe Machine
A lathe is an accurate cutting tool that is used to cut and form cylindrical shapes by holding the workpiece on the tool and rotating it against a cutting element. This entails a solid base, a revolving spindle in the head screw, and other components such as the carriage and the tail stock which enable various cutting processes such as turning, facing, and threading. This is because the machine is precise and capable of creating fine and intricate pieces making it an important tool in manufacturing.
Main Parts of Lathe Machine
Let's take a closer look at these vital parts:Bed
It is a principal component of the lathe machine. The bed is made of cast iron in its construction and it comes with a flat and even surface that is machined flat. The bed has been provided with legs and floor bolts and thus can be bolted to the floor. One end of the bed houses the headstock, while the tailstock is located at the other end. The carriage moves smoothly on the guideways between the headstock and the tailstock.The guideways come in two primary forms: flat and inverse 'V'. The inverted 'V' guideways provide better guidance and maximum control when aligning the saddle and tailstock, as well as easy shedding of metal shavings during turning processes. Although flat guideways are common in older machines and are suitable for heavy work involving large pieces, their precision is slightly lower than that of the 'V' shaped guideways.
Headstock
The headstock is well secured by being mounted to the inner guideways on the left side of the lathe bed. It houses a hollow spindle and contains the mechanism responsible for driving the spindle at various speeds. Depending on the design, the headstock may incorporate one of the following systems for driving and adjusting spindle speeds:- Stepped Cone Pulley Drive
- Back Gear Drive
- All Gear Drive
Tailstock
It is mounted on the inner ways on the right-hand side of the lathe bed opposite to the headstock. Its body has been drilled to contain a hole for containing the tailstock spindle which goes forward and backward within the bore. The spindle has a through hole that tapers to accommodate the dead center, or the shanks of drills, and reamers. When clockwise is turned at the tailstock handwheel, then the spindle moves forward and when anticlockwise is turned then the spindle is withdrawn back into the bore.The tailstock serves two primary functions:
- Supporting Long Workpieces: It offers assistance to one end of a lengthy workpiece when being worked between centers.
- Tool Holding: The tailstock is also used in holding tools like drills, reamers, and taps during operations like drilling, reaming, and tapping respectively.
Carriage
The carriage is located on the lathe bed guideways between the headstock and the tailstock. It can be moved on the bed in such a way that will allow it to slide along either towards or away from the headstock and is a key component in the support, movement, and positioning of the cutting tool. The carriage is composed of several key components:
- Saddle
- Apron
- Cross-Slide
- Compound Rest
- Compound Slide
- Tool Post
All these parts make it possible for the operator to exercise great control over the tools during the various operations of machining.
Saddle:
The ”saddle” is part of the carriage assembly. This is an “H” type casting that joins the two-bed guideways, like a bridge. It fits over the bed and moves along the guideways between the headstock and the tailstock. The saddle or the whole carriage can be shifted either by hand feed or power feed, depending on the need during machining operations.Cross slide:
The cross slide is positioned on the saddle and the cross slide traverses in dovetail guideways parallel to the bed guideways. It can support compound rest, compound slides, and tool posts. The cross-slide handwheel is also used to rotate the cross-slide in a right-angled direction to the axis of the lathe. This movement can also be power-driven for additional features and anything that would afford the consumer that much more comfort. The rim of the handwheel is graduated so you can set the feed rate accurately and has feeds as small as 0. 05mm.Compound rest:
It is an integral part that connects the cross-slide to the compound slide through a nut and screw arrangement. It is directly fixed on the cross-slide through a tongue and groove system to guarantee stiffness and coaxiality. The compound rest has a circular base with angular graduations so that it can be rotated to the required position especially when turning tapers.Right to the compound rest by a dovetail joint is the top slide, which is referred to as the compound slide, which enhances the adjustment of the tool. The cutting tool holder is situated on top of the compound slot known as the tool post to control the movement during the machining operations.
Tool post:
The tool post is fixed at the top of the compound slide and is intended to grip the cutting tools firmly and accurately. Given the type of operation, the right tool is chosen, positioned on the tool post, and put at the best working angle. Various types of tool posts are available, each offering different advantages: Various types of tool posts are available, each offering different advantages:Single Way Tool Post
Four-Way Tool Post
Quick Change Tool Post
Lead screw
The lead screw is a long shaft that has threads on it and it acts as the master screw of a lathe. It is mainly used during the cutting of threads to transfer the carriage a specific distance. Leadscrews are normally Acme threaded, this makes the leadscrew robust while at the same time being capable of free and smooth motion.The lead screw is located with two bearings on the face of the lathe bed, to reduce the loading on the lathe and its operation. On the leadscrew, there is a gear known as the “gear on the leadscrew.” While cutting the threads, the leadscrew has to be engaged and this is done using the half-nut lever present in the apron so that the carriage can move in correspondence to the spindle reversal.
Feed rod
It is mounted on the front side of the lathe bed and it lies parallel to the leadscrew. A steel with a series of grooves along the length of the bar, so that it is capable of transmitting power. From the spindle, power is transmitted through a gear system to the feed rod.The feed rod helps to move the carriage and the cross slide during the machining process, apart from thread cutting. A worm gear fixed to the feed rod regulates these motions and assures everything functions properly.