Linear-Guide CNC Lathes: Precision, Speed, and Light-Duty Production

A linear way CNC lathe is a CNC lathe that is equipped with linear guideways, which carry and move the tools on the linear rails with the traveling blocks during operation. The linear way CNC lathe is designed to machine workpieces that are relatively lightweight with fast speed and high accuracy, which is able to benefit the manufacturers of light-duty productions.

A CNC lathe is a machine that allows the workpieces to rotate with the rotary spindle, and the cutting tools traverse or reciprocate on the workpieces in order to remove parts of materials from the required areas, which may be either on the surfaces or covers from the surfaces to the inner parts of the workpieces. In combination with the CNC technology, the above processes can be performed with the computerized adjustment and maneuver related to the speed, positions, directions, and feeds, etc.

When the CNC technology is employed in a lathe machine, from the design of the products to the operation of machining processes, there are the corresponding systems that are in charge of each task respectively. For the designing process of the products, the computer-aided design (CAD) system is to allow the programmers to use the software to design the 2D or 3D models of the products. As for the conduction of machining processes, the computer-aided manufacturing system transforms the programs into codes as the instructions provided for the processes.

In addition to the techniques in the design and manufacturing processes, whether or not the components on the CNC lathe can properly coordinate with each other have a lot to do with the efficiency of the works and the quality of the products. So, let's learn about how a CNC lathe is constructed first.
 

Construction of CNC Lathe

On a CNC lathe, there are several systems that contain the assemblies of components, which make up the mechanisms that are required in each machining procedure. These systems include the power supply system, the work-holding system, the machining system, and the motion transmission system.
 

Power Supply System

The power supply system refers to the delivery of power or energy, which can be hydraulic, pneumatic, or electrical energy, from the source to the motion transmission system.
 

Work-holding System

The work-holding system contains the equipment that holds the workpieces and the cutting tools respectively. The equipment that holds the workpieces is combined with the rotary spindle and the clamping devices, either a chuck or a collet, which secure the workpiece as it rotates with the spindle.
 

Machining System

The machining system is the components that directly take part in the working site, which are the rotary spindle and the cutting tools. The rotary spindle is responsible for facilitating the movement of the workpieces. Being attached to the clamping device on the headstock, the workpieces are driven to rotate as the spindle turns. As for the cutting tools, they are specially designed cutters with blades on the cutting tips and applied for removing the materials from the workpieces with the teeth or flutes on the blades.
 

Motion Transmission System

The motion transmission system can be derived from the power supply system. This system contains the mechanism that allows the moving parts including the spindle and the guideways to move, which transforms the mechanical or electrical energy into kinetic energy in either rotary or linear forms of motion and delivers the motion required for the moving parts on the machine.
 

What Is the Role of the Guideways on a CNC Lathe?

No matter what kind of CNC machines, such as the CNC milling machine or the CNC lathe, the guideways are used to drive the rotary or linear motion of the connected components. Especially for the CNC lathe, the guideways specifically serve for the motion that is provided for the cutting tools.

On the CNC lathe, the cutting tools, which are held with the tool holder, are advanced to cut through the workpiece on axes as the traveling blocks, which support the tool holder, move forward and backward. In other words, it is the guideways that facilitate the movements of the cutting tools. But what makes the traveling blocks move?

In general, there are two types of guideways that are commonly applied in the motion transmission system, including box ways and linear ways, and these two types are named after their shapes. The former is also called the dovetail ways, since they come in the shape of a box with dovetail joints, and have a wide surface, which allows heavier loads to be fed onto. The latter is also called the linear slides since they are simply the linear bearings with relatively narrower surfaces of the traveling blocks, which makes them more suitable for lighter loads instead.
 

What Are Linear Ways Made up of?

The linear ways consist of two main parts, including the rails and the traveling blocks. Two traveling blocks are arranged on two rows of rails, which make the common type of guideway assembly on a CNC lathe.
 

Rail

The rail is designed similar to the ball bearings or roller bearings, but different from the surface above. The ball bearings and roller bearings are made as cylindrical shapes, which have no edges on the sides. While the rail on the linear way has a flat surface above, this provides stable support for the traveling block, as well as the tool holder and the cutting tools.
 

Traveling Block

The traveling block is arranged above the tail, which can be recognized as the base of the tool holder on the CNC lathe. During operation, the tool holder is attached to the surface of the traveling block. As the rotary motion, which is transmitted from the power supply system, is transformed into linear motion for the rail, the rail would drive the traveling block with back and forth movements, which thereby cause the tool holder to move.
 

Linear Ways vs. Box Ways

Dynamic Stiffness

The dynamic stiffness of the guideways refers to the stiffness of this mechanism when it moves. Since the box ways provide wider surfaces for the tool holder to be placed on, the mechanism would be relatively stable compared to the narrower surfaces of the linear ways. Therefore, when it comes to the dynamic stiffness, the box ways are superior to the linear ways.
 

Compatible Application

The more stable the guideways are, the heavier the load capacity is. According to the dynamic stiffness of each type of guideways, the linear ways are suitable for lighter loads, and the box ways would be preferred when heavier loads are required
 

Speed

With the variation in the amount of load, the working speed of the guideways would be different accordingly. In other words, the linear ways, which are in charge of lighter loads, work faster than the box ways, which serve for relatively heavier loads.
 

Vibration Damping

When the components of a mechanism move, there would be vibration produced from the moving parts. To determine the vibration damping ability of the guideways, stability matters. From here we can know that the box ways would perform better in the vibration damping ability than the linear ways.