C6240K Manual Lathe: A Precision - Oriented Machining Workhorse

C6240K Manual Lathe: A Precision - Oriented Machining Workhorse

In the realm of traditional machining, the C6240K manual lathe holds a significant place. Renowned for its reliability, versatility, and precision, this lathe has been a staple in various industries, from small - scale workshops to large - scale manufacturing plants.

Structural Design and Components

The Bed: The bed of the C6240K is the foundation of the machine. Constructed from high - grade cast iron, it offers exceptional stability and rigidity. Its robust design allows it to withstand the vibrations and forces generated during machining operations. The bed's surface is precisely machined, and the guideways, which are often ultra - frequency hardened and ground, ensure smooth and accurate movement of the carriage and other components. This not only contributes to the long - term accuracy of the lathe but also extends the lifespan of the guideways, reducing the need for frequent replacements.

Headstock: The headstock is a crucial component that houses the main spindle. The spindle of the C6240K is designed to rotate the workpiece at various speeds. It is driven by a powerful motor, and the speed can be adjusted through a series of gears. The spindle is supported by high - quality bearings, which enable it to rotate smoothly and with minimal run - out. This ensures that the workpiece rotates concentrically, resulting in high - precision machining. The headstock also contains the gearing mechanism that allows for different spindle speeds, catering to a wide range of materials and machining operations. For example, when machining soft materials like aluminum, a higher spindle speed can be selected to increase the material removal rate, while for harder materials such as steel, a lower spindle speed with higher torque is more appropriate.

Tailstock: Located at the opposite end of the headstock, the tailstock provides additional support for the workpiece, especially when machining long shafts or slender parts. It can be adjusted along the length of the bed to accommodate workpieces of different sizes. The tailstock features a quill that can be extended or retracted. The quill is often used to hold a center, which supports the end of the workpiece, or other tooling such as a drill bit for machining holes in the end of the workpiece. The ability to adjust the position of the tailstock and the extension of the quill gives operators the flexibility to work with a variety of workpiece lengths and machining requirements.

Carriage and Cross - Slide: The carriage is responsible for the longitudinal movement of the cutting tool along the length of the workpiece. It rides on the guideways of the bed and is manually operated using handwheels. The cross - slide, on the other hand, enables the lateral movement of the cutting tool, perpendicular to the axis of the workpiece. This movement is used for operations such as facing, where a flat surface is created on the end of the workpiece, and for controlling the depth of cut during turning operations. The combination of the carriage and cross - slide allows for precise control over the movement of the cutting tool, enabling the creation of complex shapes and accurate dimensions.

Tool Post: The tool post is where the cutting tools are mounted. The C6240K can accommodate a variety of cutting tools, including turning tools, boring tools, threading tools, and grooving tools. These tools can be easily changed and adjusted on the tool post to suit different machining operations. The tool post is designed to hold the cutting tools securely in place, ensuring that they maintain their position during machining and do not move or vibrate, which could affect the quality of the machined surface.

Machining Capabilities

Turning Operations

External Turning: One of the primary functions of the C6240K is external turning, where material is removed from the outer diameter of the rotating workpiece. By carefully adjusting the position of the cutting tool using the carriage and cross - slide, operators can create cylindrical surfaces with tight tolerances. For example, in the production of shafts, external turning is used to achieve the desired diameter and surface finish. The lathe's ability to control the feed rate and depth of cut precisely allows for the creation of smooth and accurate cylindrical shapes.

Internal Turning (Boring): The C6240K is also capable of internal turning, or boring. This operation involves enlarging an existing hole or creating a new hole with a specific diameter and surface finish. A boring bar, with a cutting tool attached to its end, is used for this purpose. The operator can adjust the position of the boring bar using the cross - slide to control the diameter of the hole being bored. This is particularly useful in manufacturing components such as engine cylinders, where precise internal diameters are crucial for proper functioning.

Facing Operations

Facing operations are used to create a flat surface on the end of the workpiece. With the C6240K, the operator moves the cutting tool radially (using the cross - slide) while the workpiece rotates. This results in a smooth, flat surface that is perpendicular to the axis of the workpiece. Facing is often performed to prepare the workpiece for further machining operations, such as drilling or threading, or to achieve a specific length dimension.

Thread Cutting

The C6240K can cut both metric and imperial threads. Thread cutting is a complex operation that requires precise coordination between the rotation of the workpiece and the movement of the cutting tool. The lathe is equipped with a gear - change mechanism that allows the operator to select the appropriate pitch for the desired thread. By engaging the lead screw, which is connected to the carriage, the cutting tool moves along the length of the workpiece at a specific rate, creating the thread. This is essential in manufacturing parts that require threaded connections, such as bolts, nuts, and various mechanical components.

Grooving and Parting

Grooving involves cutting a narrow groove or channel into the surface of the workpiece. This can be used for various purposes, such as creating a location for an O - ring or separating a finished part from the raw material. Parting, on the other hand, is the process of cutting the workpiece completely through to separate it into two or more pieces. A parting tool, which has a narrow, sharp cutting edge, is used for these operations. The C6240K's ability to control the depth and width of the groove or cut accurately makes it suitable for producing parts with specific groove requirements.

Drilling and Boring

In addition to turning operations, the C6240K can be used for drilling and boring holes in the workpiece. When drilling, a drill bit is mounted in the tailstock quill, and the workpiece is rotated. The drill bit is then fed into the workpiece using the hand - operated movement of the tailstock quill. Boring operations, as mentioned earlier, can be performed using a boring bar mounted on the tool post. This versatility allows for the production of parts that require holes of different sizes and accuracies.

Technical Specifications

Spindle Speed Range: The C6240K typically offers a wide spindle speed range, such as 40 - 1400 RPM. This range allows operators to select the most appropriate speed for different materials and machining operations. For soft materials like plastics or aluminum, higher spindle speeds can be used to increase the machining efficiency, while for harder metals like steel or cast iron, lower spindle speeds are required to ensure proper tool life and machining accuracy.

Max Turning Diameter and Length: The maximum swing over the bed of the C6240K is usually around 460 mm, which determines the maximum diameter of the workpiece that can be machined. The maximum turning length can vary, with common options being 1500 mm or 2000 mm, enabling the machining of relatively long workpieces. This makes the lathe suitable for a variety of applications, from small - scale component production to the machining of longer shafts.

Feed Rates: The lathe has both longitudinal and cross - feed rates. The longitudinal feed range, which controls the movement of the cutting tool along the length of the workpiece, can be in the range of 0.0832 - 4.6569 mm/r. The cross - feed range, for the lateral movement of the cutting tool, is typically around 0.048 - 2.688 mm/r. These feed rates can be adjusted by the operator to achieve the desired surface finish and material removal rate.

Thread - Cutting Capabilities: The C6240K is capable of cutting a wide range of threads. It can handle metric threads with pitches ranging from 0.5 - 240 mm and imperial threads with a range of 80 - 1/4 t/inch. The number of different thread types that can be cut is often extensive, for example, it may be able to cut 49 different inch - thread species and 57 different module - thread species. This versatility in thread cutting makes it suitable for industries where threaded components are commonly used.

Motor Power: The main motor power of the C6240K is usually around 7.5 KW. This power is sufficient to drive the spindle at various speeds and handle different machining operations, even when working with tough materials. The motor is designed to provide stable and reliable power, ensuring smooth operation of the lathe.

Operator Skill and Manual Operation

Operating the C6240K manual lathe requires a high level of skill and knowledge. The operator has full control over the movement and positioning of the cutting tool. Hand wheels and levers are used to move the carriage, cross - slide, and tool post. For example, to control the depth of cut during turning, the operator turns the hand wheel of the cross - slide. The feed rate is adjusted by engaging different gears or using a variable - feed mechanism. The operator must also have a good understanding of machining principles, such as the relationship between spindle speed, feed rate, and depth of cut, to achieve the desired results. Additionally, they need to be able to select the appropriate cutting tools for different materials and operations and know how to set up the lathe correctly, including mounting the workpiece securely in the chuck or between centers.

Applications

Small - Scale Manufacturing and Repair Shops: In small - scale manufacturing and repair shops, the C6240K is a valuable asset. It can be used to produce custom - made parts, repair damaged components, or create prototypes. The manual operation allows for flexibility in machining, as the operator can make on - the - fly adjustments based on the specific requirements of the job. For example, a small - scale machine shop may use the C6240K to produce replacement parts for old machinery or to create unique components for specialized equipment.

Educational Institutions: Educational institutions, such as vocational schools and technical colleges, often use the C6240K to teach students the fundamentals of machining. The manual operation of the lathe helps students develop practical skills and an understanding of machining processes. By working with a manual lathe, students can learn about tool selection, setup, and the importance of precision in machining. This hands - on experience is essential for those pursuing careers in the manufacturing industry.

General Manufacturing: In general manufacturing, the C6240K is used for a variety of applications. It can be used to machine parts for the automotive, aerospace, and machinery industries. For example, in the automotive industry, it may be used to produce small - scale components such as shafts, bushings, or threaded parts. In the aerospace industry, where precision is of utmost importance, the C6240K can be used to machine parts for aircraft engines or other critical components, provided that the required tolerances can be met.

In conclusion, the C6240K manual lathe, with its solid construction, wide range of machining capabilities, and precise operation, continues to be a reliable and versatile machining tool. Despite the advancements in CNC technology, the C6240K still has its place in industries and applications where manual control, flexibility, and cost - effectiveness are valued.