Many people still couldn’t understand CNC Turning very well. And there is no detailed and comprehensive introduction for it. So today i write this article, which including the definiation of CNC Turning, How does it work & it’s process, Different Types, It’s materials, CNC lathe Machine, CNC Turning Center & it’s benefits, and sure it will help you to get understand them clearly.
Table of Contents
What is CNC Turning
Computer Numeric Control Turning is an industrial machining operation that removes material with a cutting tool to create cylindrical pieces. Machine tools are fed to the component, eliminating material to make a finished piece, and are most commonly employed to generate cylindrical parts.
This method is best suited to big production runs with short lead times and is applied to assist a wide range of sectors, including:
- The electrical sector
- Machining using electrical discharge
- Fabrication of woodworking materials
- Metal removal
CNC turning utilizes turning-capable machinery, such as a lathe or a turning center. This operation’s axis of rotation could be oriented horizontally or vertically. The latter is utilized for workpieces with a large radius relative to their length.
CNC Turning is one part of CNC Machining, if you are looking for CNC Machining for your projects & want to get quotations, feel free to contact us
The CNC Turning Process
In the CNC Process, a bar of metal material is clamped in a chuck, rotated, and then a tool is inserted to remove the material and create a form for the final product. This can be performed with a machine that produces one or more shapes.
From computerizing the intended design to producing the final product, the process consists of four parts. These are the steps followed in the CNC turning process:
- Creating the design of the part in CAD
- Using the CAD files to create machining codes
- CNC Lathe Setup
- Manufacturing the final product
Various turning parameters must be considered during the turning process and are spindle speed, work piece diameter, cutting diameter, feed rate, axial cut depth, and radial cut depth. These are all critical and are affected by factors such as component and tool material, tool size, and finishing requirements.
CAD Designing
In this process, 3D CAD files are prepared and transferred directly to the manufacturing section using programs like Solidworks and Fusion 360.
Another option is to create a 2D drawing and send it to manufacture. Both approaches work, however making 2D is more complicated due to how manual the process is, and consequently takes more time.
Machining Codes Creation
To produce the final product, the manufacturing engineer creates G code and the M code for the machining. The machining codes for 3D files are generated automatically, but the machining codes for 2D files are generated manually
Lathe Setup
This is the step where the machine is setup. Here are steps followed in the process of lathe setup.
- Ensuring the electricity is turned off
- Fixing the component in the chuck
- Loading the tool turret
- Calibration
- Upload the program
Part Production
The CNC turning process can be finished on the exterior or inside of a work item, which is referred to as boring. The procedure can also be used to do a variety of additional operations, such as:
- Grooving: The process of cutting grooves or creating narrow spaces in work pieces.
- Taper turning: Produces a cylindrical shape with a steadily diminishing diameter.
- Drilling: Creates circular holes, which are commonly used for screws and bolts.
- Facing: Creates a flat surface perpendicular to the milling cutter’s axes.
- Parting: The process of separating one portion of a work item from another.
- Knurling: The process of creating vertical, horizontal, or crossed lines on a work piece.
- Threading: The process of creating grooves that can be screwed into other things.
The process used to work on the initial material will determine how the final product turns out.
Types of Turning
A cutting tool removes material from the outside diameter of a spinning workpiece during the turning process. Turning’s primary goal is to reduce the workpiece’s diameter to the appropriate size.
There are rough and finish turning operations. Rough turning tries to process a piece to within a set thickness by removing the most material in the least period of time, neglecting accuracy and surface finish. Finish turning results in a workpiece with final exact dimensions and a smooth surface finish.
There are four types of turning
Step turning
It is a turning technique in which a series of steps of varying diameters is made using a lathe machine. It produces two surfaces with a sharp difference in diameters between them.
Taper turning
When a workpiece is turned, the cutting tool moves at an angle to the workpiece’s axis, giving the workpiece a tapered shape. The diameter of the workpiece varies consistently from one end to the other
Chamfer turning
The process of chamfering involves beveling the work piece’s very end. It makes an ordinarily square edge that connects two surfaces with different turning diameters angular.
Contour turning
In the finishing procedure, the cutting tool travels axially along a path with a predetermined shape. The turning tool must be moved in a trajectory of a complex flat curve depending on the part profile in order to construct the part profile.
Materials for turning
The original form of the material in turning is a piece of stock from which the workpieces are cut. This stock comes in various configurations, including solid cylindrical bars and hollow tubes. Here are steps that can be followed in the selection of the materials for turning:
- Define the material specifications: These can include mechanical, thermal, or other material specifications, in addition to cost and surface finish. Consider how you’ll use your parts and the environment they’ll be in.
- Identify candidate materials: Select a few candidate materials that meet all or most of your technical specifications.
- Choose the most appropriate material: Typically, two or more of the design requirements must be compromised in this situation, for instance, mechanical performance and cost.
Using the above steps, turning may be done on many materials, including metals and polymers. The commonly used materials are Magnesium, Brass, Aluminum, Steel, and Zinc.
Metals are most utilized in applications requiring high strength, hardness, and thermal resistance. Plastics are lightweight materials with a wide range of physical qualities that are frequently utilized for chemical resistance and electrical insulation.
What is CNC Lathe
CNC lathe machines rotate a bar of material, allowing the cutting tool to remove material from the bar until only the desired product remains.
The primary spindle secures and rotates the material, while the cutting tool may be moved along numerous axes. A CNC lathe frequently produces cylindrical or symmetrical pieces around an axis.
Components of a CNC Lathe Machine
CNC lathe machines are divided into the following components:
Headstock
Headtock is the front component of a CNC lathe is the location of the drive motor along the mechanics that power the spindle.
CNC lathe Bed
The bed is just a foundation plate that lies on the table and supports other machine components. The carriage travels over the heat-treated bed, which is designed to endure the machining impacts
Chuck
The chuck’s jaws grasp the machined item. It is directly attached to the spindle but removable, allowing different sized components to be machined.
Tailstock
Tailstock is the other end of a CNC turning center. It is attached directly to the bed and serves to support longer workpieces. The hydraulic force is provided by the tailstock quill.
The spindle is still the driving power, and the tailstock just runs with the component. When face turning is required, using a tailstock is not recommended since it will be in the way
Carriage
The carriage is supported by means that let it to slide with the rotating workpiece. It retains the instruments, enabling the cutting operation to occur.
CNC Control Panel
The control panel is the location of computer numerical control. The panel allows the operator to configure and launch the application.
Tool turret
The carriage is frequently replaced with a turret on newer vehicles. They can carry numerous tools at once, reducing the time it takes to transfer from one operation to the next.
Types of Lathe
There are numerous classifications of lathe machines; you can select the suitable classification of lathe machine based on your processing and precision needs.
Speed Lathe Machine
Machine Lathe machines of this type are simple in design, with a bed, headstock, tailstock, and tool post positioned on an adjustable slide and no feed box lead screw or carriage.
It has a high-speed capability and is operated manually. High-speed lathes have a speed range of about 1200 to 3600 RPM. This lathe is used to turn wood, center it, polish it, and machine it.
Engine Lathe Machine
The engine lathe is the most common type of lathe machine, and it is powered by a gear or pulley mechanism. It was used to accomplish turning, end face, grooving, knurling, and threading operations. The engine lathe’s feed mechanism may move the cutting tool in both the longitudinal and lateral directions. The center lathe can be categorized as a belt drive, motor drive, or reducer depending on the source of the drive.
Bench Lathe Machine
Bench lathes are small machines that are positioned on a bench and can be used for smaller and more precise work. Has parts that are comparable to engine lathes and high-speed lathes and performs similar operations, except for machine size.
Toolroom Lathe Machine
The tool room lathe is similar to the engine lathe in appearance, but its parts are created with greater accuracy and order, therefore this machine is utilized for high-precision grinding machining.
The machine has a wide speed range, with spindle speeds ranging from extremely low to relatively high, up to 2500rpm. It has a chuck, a taper turning attachment, a draw-in collection attachment, a steady and follower rest, and a coolant pump.
Capstan and Turret Lathe Machine
Capstan and turret lathes are engine lathe upgrades that can be employed for high-volume production and huge tasks. The machine tool’s head is a hexagonal head that may be turned to alter the operation without requiring a manual change, such as turning, end face, boring, and reaming.
Multiple tools can be fitted and fed into the job in the right sequence on these types of lathe machines. The key advantage is that various procedures and parts can be produced in a relatively short time.
Special-purpose lathe machines
Types of lathe machines are utilized for unique purposes and production operations that the other lathe cannot do. Drilling, grinding, reaming, and boring are examples of special operations.
Vertical lathes, wheeled lathes, T-type lathes, multi-axis lathes, production lathes, and tracer lathes are examples of special lathes noted for their heavy-duty manufacture of the same parts.
Automatic Lathe Machine
The automatic lathe can be utilized for mass production and can do tasks automatically. Without needing to replace the tool manually, the automatic machine will change. The advantage is that an operator can manage numerous machines at the same time. The automated lathe is a heavy-duty, high-speed machine.
CNC lathe machine
A CNC lathe is a machine tool that spins the workpiece around the main spindle, whereas a cutting tool cuts the workpiece into the required shape, and a precise set of design instructions controls both.
CNC machines are more expensive than manually run machines because of how sophisticated they are built. They assure constant product quality and do not require highly qualified personnel to operate the machine.
CNC Turning center
CNC turning centers are sophisticated computer-controlled equipment. They can have three, four, or even five axes, as well as a wide range of cutting capabilities such as milling, drilling, tapping, and turning. These machines are frequently enclosed to keep any cut material, coolant, and components contained within the machine.
There are two types of turning centers; horizontal turning centers and vertical turning centers and they have the same fundamental components but differ in their orientation. A variety of criteria influence whether you choose a horizontal or a vertical lathe, but there are some general guidelines to follow which include comparing their benefits and the specific requirements.
The benefit of a horizontal lathe is that gravity pushes the chips away from the component, causing all of the chips to fall into the chip conveyor as you turn. The advantage of a vertical lathe is that gravity helps seat your component into the work holding, but chips can be a difficulty, especially if your part is concave because the chips can trap internally.
In general, horizontal lathes are more adaptable since they can have longer bed lengths compared to spindle sizes, and they can also use bar feeders and tailstocks, which are uncommon on verticals. The vertical lathe, on the other hand, is ideal for milling big-diameter short pieces, especially if they are heavy.
Because horizontal lathes have been around longer, they probably account for 60 or 70% of the market, but which one to choose depends on the user’s requirements.
What are the Benefits of CNC Turning
Recent developments in machining technology are utilized by CNC turning, and its advantages include:
Fast Speed
There is a lower chance of error when tasks specified by programming are carried out on CNC lathes. CNC turning can produce thousands of pieces quickly while maintaining a stable final result. Finally, you can receive the industry’s necessary parts or components faster than with other options.
Accuracy
CNC turning machines provide excellent precision for manufacturing items. Because the CNC machine is computer-controlled, when programmed to execute a job, it produces a consistent and accurate cut. This ensures product quality and can be repeated indefinitely in the same way.
Cost-effectiveness
The most notable advantage of this service is that it can be inexpensive. Because a machine works continuously, hiring a person to physically make parts at scale is much more expensive than having a machine do it. Additionally, because of its nature, you will not need to purchase new equipment or tools as frequently.
Flexibility
They have a variety of size capabilities to fulfill the needs of your diverse applications. The adjustment is relatively simple because the tasks performed by this machine are coded. The machine operator can create a component for your company and then make the necessary programming adjustments to produce something completely different by accessing the keyboard. As a result, you may rely on the same manufacturing business or precision CNC machining service provider to supply a huge number of distinct parts.
Safety
To ensure total safety, manufacturing companies follow strict safety standards and regulations. Because the turning machine is automatic, less work is necessary because the operator is simply responsible for monitoring the machine. Similarly, the lathe body uses fully enclosed or semi-enclosed protection mechanisms to prevent flying particles from the processed object and to safeguard the crew.
