What is Capstan And Turret Lathe?

What is Capstan Lathe?

Capstan lathe is the modified form of the engine lathe and center lathe in which the tailstock is replaced with a hexagonal turret tool head. It was first developed by Pratt and Whitney in America in 1860.

It was necessary to develop a capstan lathe because there was only one tool holder in the center lathe and only one tool can be mounted in the tailstock. As a result, it was very time-consuming every time we had to change the tool while changing the operation to be performed on the workpiece. Center lathe was not suitable for mass production.

To overcome these problems, a capstan lathe was developed. capstan lathe is a modified form of the center lathe. This turret tool head has 6 different tool types. The turret tool is rotated to obtain the required tool for the operation.

It is used in mass production, i.e. to manufacture a large number of end products with the highest accuracy and precision in the shortest possible time.

It is a semi-automatic lathe. It is called semi-automatic because the machining processes such as drilling, facing, thread cutting, turning, etc. are carried out automatically without changing tools, while other works such as workpiece clamping, toolset, and cooling are carried out manually.

Working of Capstan Lathe

Six tools are available in the hexagonal tool holder in the capstan lathe. First, the workpiece, which is to be changed into the desired shape and size, is placed in the chuck.

This chuck can be a three-jaw or four-jaw chuck. This workpiece rotates with the chuck, which is connected to a spindle.

The hexagonal tool head has six different surfaces to accommodate six different tool types.

When the workpiece with the chuck starts to rotate, the hexagonal tool head is moved towards the workpiece by moving the saddle. This hexagonal tool head can be rotated and by turning the tool required for machining is directed towards the workpiece.

After the required tool faces the workpiece, the tool is brought into contact with the workpiece by advancing the ram and the required operation is carried out.

After the first operation has been completed and the ram has been moved backward, the turret automatically switches on and the tool mounted on the next face comes into operation.

What are the Key Features and Functions of Capstan Lathe?

Capstan lathe machines are characterized by their turret head, which holds multiple cutting tools simultaneously. This turret can rotate, indexing tools into position as needed for different machining operations. Here are some key features and functions of capstan lathes:

Turret System: The heart of a capstan lathe, the turret system, enables quick tool changes and reduces setup time, increasing productivity.
Automatic Feeding: Capstan lathes often incorporate automatic feeding mechanisms for the workpiece, ensuring consistent and uniform cuts.
High Speeds: These machines are designed for high-speed machining, making them suitable for mass production of small to medium-sized components.
Versatility: Capstan lathes can perform a wide range of operations, including turning, facing, threading, drilling, and more, offering versatility in manufacturing processes.
Precision Control: With precise control over cutting parameters, capstan lathes produce accurate and repeatable results, meeting stringent quality standards.

Applications Of Capstan Lathe Across Industries

The versatility and efficiency of capstan lathe machines make them indispensable in various industries:

Automotive: Capstan lathes are used to manufacture precision components for engines, transmissions, steering systems, and other automotive parts.
Aerospace: In the aerospace sector, these machines produce critical components like landing gear parts, hydraulic fittings, and aircraft engine components.
Electronics: Capstan lathes play a role in producing intricate parts for electronic devices, such as connectors, housings, and components for printed circuit boards.
Medical Devices: Manufacturers rely on capstan lathes to create precise components for medical devices, including implants, surgical instruments, and diagnostic equipment.
General Engineering: From nuts and bolts to specialized tools and equipment, capstan lathes contribute to the production of a wide range of engineering components.

Advantages of Capstan Lathe Machines

The adoption of capstan lathes offers several advantages for manufacturers:

Increased Productivity: Automation and quick tool changes lead to higher productivity rates, reducing manufacturing lead times.
Improved Accuracy: The precision control of capstan lathes ensures consistent and accurate machining, minimizing errors and rework.
Cost Savings: Efficient machining processes result in cost savings through reduced labor costs, material waste, and downtime.
Flexibility: Capstan lathes can handle various materials, geometries, and machining operations, offering flexibility in production.
Quality Assurance: Consistent machining results in high-quality components that meet or exceed industry standards and customer expectations.

What is Turret lathe?

A turret lathe is a type of metalworking lathe that’s characterized by the use of interchangeable cutting tools. Like traditional lathes, it presses a stationary cutting tool against a rotating workpiece.

Turret lathes are unique, however, because of their interchangeable cutting tools. The cutting tool can be quickly changed to accommodate a specific manufacturing application.

It evolved from earlier lathes with the addition of the turret, which is an indexable toolholder that allows multiple cutting operations to be performed, each with a different cutting tool, in easy, rapid succession, with no need for the operator to perform set-up tasks in between (such as installing or uninstalling tools) or to control the toolpath.

Benefits of Turret Lathes

Turret lathes are more versatile than traditional lathes because of their interchangeable cutting tools. Traditional lathes also often support multiple cutting tools, but these are more difficult to change than turret lathes.

To change the cutting tool in a traditional lathe, a worker must detach the existing cutting tool, remove it from the lathe, and then reattach another cutting edge.

Turret lathes, on the other hand, can be equipped with several cutting tools at the same time. The cutting tool does not need to be replaced. Rather, the turret lathe can automatically switch to the appropriate cutting tool, which leads to faster and more efficient production processes for manufacturing companies.

It takes only a few seconds for a turret lathe to be switched to a different cutting tool, while it takes a human worker several minutes to manually change the cutting tool in a traditional lathe.

Types of Turret Lathes

There are many different types of turret lathes. For example, some turret lathes are numerically controlled (NC) while others are computer-controlled (CNC). NC turret lathes are older and usually use punch cards or similar rudimentary control methods.

In comparison, CNC turret lathes are newer and use more advanced control methods that require the use of a computer. Turret lathes can also be classified according to how they work. There are automatic turret lathes that can perform a variety of processes with little or no manual labor.

There are also manual turret lathes that require at least some manual labor. Other common types of turret lathes are semi-automatic, vertical, and flat lathes.

#1. Horizontal, Manual turret lathe

The archetypical turret lathe, and the first in order of historical appearance, is the horizontal-bed, manual turret lathe. The term “turret lathe” without further qualification is still understood to refer to this type.

The formative decades for this class of machine were the 1840s through 1860s, when the basic idea of mounting an indexable turret on a bench lathe or engine lathe was born, developed, and disseminated from the originating shops to many other factories.

#2. Semi-Automatic Turret Lathe.

Sometimes machines similar to those above, but with power feeds and automatic turret-indexing at the end of the return stroke, are called “semi-automatic turret lathes”. This nomenclature distinction is blurry and not consistently observed.

The term “turret lathe” encompasses them all. During the 1860s, when semi-automatic turret lathes were developed, they were sometimes called “automatic”.

What we today would call “automatics”, that is, fully automatic machines, had not been developed yet. During that era both manual and semi-automatic turret lathes were sometimes called “screw machines”, although we today reserve that term for fully automatic machines.

#3. Automatic Turret Lathe.

During the 1870s through 1890s, the mechanically automated “automatic” turret lathe was developed and disseminated. These machines can execute many part-cutting cycles without human intervention.

Thus, the duties of the operator, which were already greatly reduced by the manual turret lathe, were even further reduced, and productivity increased. These machines use cams to automate the sliding and indexing of the turret and the opening and closing of the chuck.

Thus, they execute the part-cutting cycle somewhat analogously to the way in which an elaborate cuckoo clock performs an automated theatre show.

Small- to medium-sized automatic turret lathes are usually called “screw machines” or “automatic screw machines”, while larger ones are usually called “automatic chucking lathes”, “automatic chuckers”, or “chuckers”.

#4. Computer Numerical Control Turret Lathe.

When World War II ended, the digital computer was poised to develop from a colossal laboratory curiosity into a practical technology that could begin to disseminate into business and industry.

The advent of computer-based automation in machine tools via numerical control (NC) and then computer numerical control (CNC) displaced to a large extent, but not at all completely, the previously existing manual and mechanically automated machines.

Numerically controlled turrets allow automated selection of tools on a turret. CNC lathes may be horizontal or vertical in orientation and mount six separate tools on one or more turrets. Such machine tools can work in two axes per turret, with up to six axes being feasible for complex work.

#5. Vertical Turret Lathe.

Vertical turret lathes have the workpiece held vertically, which allows the headstock to sit on the floor and the faceplate to become a horizontal rotating table, analogous to a huge potter’s wheel. This is useful for the handling of very large, heavy, short workpieces.

Vertical lathes in general are also called “vertical boring mills” or often simply “boring mills”; therefore, a vertical turret lathe is a vertical boring mill equipped with a turret.

Difference between capstan and turret lathe

Capstan and Turret lathes are the advancements of the Engine lathes and center lathes in which the tailstock is replaced by a hexagonal turret tool head with 6 different tools in the turret where the turret tool is rotated according to process requirements in each operation.

The capstan and turret lathe although appear to be identical at first sight but a lot of differences in construction, operation, and use. In this article, you can check it out some difference between these two lathe machines.

Capstan lathe	Turret lathe
1. Lightweight machine.	1. Heavyweight machine.
2. These are usually horizontal lathes.	2. Turret tool head is directly fitted on the saddle and both of them appear like one unit.
3. Turret head is mounted on a slide called ram which is mounted on the saddle.	3. Suitable for heavier chucking work.
4. Suitable for bar work.	4. The saddle is moved to provide feed to the tool.
5. The saddle is locked at a particular point and the ram is moved to provide feed to the tool.	5. They are heavy and durable.
6. Only a limited amount of feed and depth of cut is provided for machining.	6. More feed and depth of cut are provided for machining.
7. The cross slide is mounted on a carriage that rests on the bed ways between the headstock and the ram.	7. Some turret-type lathes are equipped with side hung type carriage.
8. The turret tool head is indexed automatically.	8. To index the turret tool head, a clamping lever is released and the turret is rotated manually.
9. Feed stop screws are used to control the distance of tool movement which is at the rear side of the turret.	9. Limit dogs are used to control the distance of tool movement.
10. No such facility to moving turret at right angles.	10. Some turret lathes have the facility of moving the turret at right angles to the lathe axis.
11. Feed rod gives for longitudinal feed.	11. Feed rod does not give for longitudinal feed.
12. Used for mass production of small size equal part.	12. Used for mass production of large size equal part.
13. It has hand-operated collet chucks.	13. It is accommodated with power chucks.
14. Heavy cuts on the workpiece can’t be given because of non-rigid construction.	14. Heavy cuts on a workpiece can be given because of the rigid construction of a machine.