CNC turning is a crucial machining technology that is revolutionizing various industries. By combining traditional turning methods with computer numerical control (CNC), this process ensures exceptional precision, repeatability, and production efficiency. In this article, we will delve into everything worth knowing about CNC turning, from its history and technological process to the types of turning, applications, and factors influencing service costs.
What is CNC Turning?
CNC turning (Computerized Numerical Control) is an automated machining process that involves removing surface layers of material from a workpiece to give it the desired shape. The workpiece is set in rotary motion on CNC lathes, while the cutting tool (turning tool) moves parallel, perpendicular, or in a combined manner relative to the axis of rotation. This process results in elements with cylindrical, conical, or spherical shapes.
Examples of products obtained through CNC turning include:
- Axles and drive shafts,
- Sleeves and rings,
- Screws and nuts,
- Cylinders and washers.
How does a CNC lathe work?
A CNC lathe is an advanced machine equipped with a computer control system. The CNC turning process can be divided into three main stages:
- CAD design - the designer prepares a 3D model of the element in a computer program.
- CAM programming - the model is converted into code controlling the lathe.
- CNC machining - the machine performs the cutting according to the programmed instructions.
Types of CNC lathes
There are many different types of CNC lathes, which can be categorized by:
Spindle orientation:
- Horizontal lathes: the spindle is positioned horizontally, enabling the machining of long and heavy workpieces.
- Vertical lathes: the spindle is positioned vertically, enabling the machining of large and heavy workpieces with complex shapes.
Number of spindles:
- Single-spindle lathes: they have one spindle on which the workpiece is mounted.
- Multi-spindle lathes: they have several spindles, allowing for simultaneous machining of multiple workpieces, increasing production efficiency.
Construction:
- Universal lathes: these are the most versatile type of lathes, enabling various turning operations.
- Specialized lathes: these are adapted to perform specific turning operations, such as thread turning, gear turning, or contour turning.
- Vertical boring mills: these are used for machining large and heavy workpieces with a large diameter.
- Turret lathes: these are equipped with a turret-type tool head, enabling quick tool change without interrupting the lathe's operation.
Degree of automation:
- CNC lathes: these are computer-controlled, enabling automation of the turning process and increasing its precision.
- Automatic lathes: these are equipped with mechanisms that automate individual stages of the turning process, such as material feeding, workpiece clamping, and tool change.
Types of CNC turning
CNC turning can be divided into several basic types depending on the direction of tool movement and the process used:
- Longitudinal turning: the turning tool moves parallel to the axis of rotation of the workpiece. It is usually performed in two passes of the tool - the first is defined as roughing, and the second - finishing or precision turning. It is used to create elements with an elongated shape, such as shafts, axles, or sleeves.
- Transverse turning: the tool movement is perpendicular to the axis of rotation of the workpiece. It is used for machining face surfaces, e.g., the bottom of cylinders.
- Copy turning: the turning tool moves along a template, reproducing its shape. It is used to create elements with non-standard shapes.
- Contour turning: the tool has a specially shaped blade that gives the workpiece the desired contour. It is used for the production of short rotating solids.
CNC turning parameters
In the CNC turning process, it is important to select the appropriate machining parameters, such as:
- Cutting speed: the speed at which the tool cuts the material. It depends on the type of material being machined, the type of tool, and the surface quality requirements.
- Feed rate: the speed at which the tool moves relative to the workpiece. It affects the chip thickness, surface quality, and machining efficiency.
- Depth of cut: the thickness of the material layer removed during a single pass of the tool. It affects the cutting forces, machining temperature, and process efficiency.
- Type of turning tool: the choice of the appropriate turning tool depends on the type of material being machined, the shape of the surface being machined, and the quality requirements of the machining.
- Cooling and lubrication: cooling and lubrication are necessary to ensure the correct temperature of the tool and workpiece during turning, as well as to reduce friction and tool wear.
The selection of appropriate turning parameters affects the quality of machining, tool life, and process efficiency.
Materials for CNC turning
CNC turning is a versatile machining method that allows for precise shaping of various materials. The choice of the appropriate material is crucial to achieve the desired properties of the final product. Below we present the most important information on the materials used in the CNC turning process.
Metals and metal alloys
- Aluminum: lightweight, corrosion-resistant, easy to machine. Applications: automotive (sleeves, shafts), aviation (structural elements), electronics (housings). Requires special blades to prevent chip adhesion.
- Steel and steel alloys: wide range of hardness and strength, resistance to high temperatures (in the case of heat-resistant steel). Applications: tools, shafts, sleeves, structural elements. Machining of hard steel requires carbide or ceramic tools.
- Copper and its alloys (brass, bronze): excellent thermal and electrical conductivity, corrosion resistance. Applications: electronics (contacts), decorative elements, chemical-resistant parts. Copper requires the use of coolants to prevent overheating.
- Titanium: durable, lightweight, corrosion-resistant, and biocompatible. Applications: aviation (turbine parts), medicine (implants, prostheses). Difficult to machine, requires low cutting speeds.
Plastics
- Polyacetal (POM): stiffness, dimensional stability, wear resistance. Applications: gears, guides, bearings.
- Polyethylene (PE): lightweight, resistant to abrasion and chemicals. Applications: seals, pipe elements.
- Polycarbonate (PC): transparency, impact resistance. Applications: protective covers, optical elements.
Composites and other materials
- Carbon fiber (CFRP): very light, exceptionally strong. Applications: aviation, automotive, professional sports. Difficult to machine, requires specialized tools.
- Ceramic and composite materials: resistance to high temperatures and chemicals. Applications: aviation industry, high-tech devices.
Advantages of CNC turning
- Precision: ability to achieve dimensional tolerances even at the micron level.
- Repeatability: each element is identical, which is crucial in mass production.
- Material optimization: minimizing material waste thanks to precise cutting.
- Production speed: shorter lead times thanks to process automation.
- Error reduction: eliminating human error thanks to computer control.
- Versatility: machining of various materials, from metals (steel, aluminum, copper) to plastics.
Applications of CNC turning
CNC turning is widely used in many industries due to its versatility and precision. Here are the key areas where this technology is used:
- Automotive: production of axles, shafts, sleeves, cylinders and other mechanical parts. Machining of suspension components and braking systems.
- Aerospace: manufacturing of precise parts for turbines and jet engines. Machining of aircraft structural parts.
- Medicine: production of implants, surgical instruments and prosthetic components. Machining of precision components for diagnostic devices.
- Electronics and automation: components for control systems, housings for electronic devices. Parts for robots and industrial machines.
- Household appliances and furniture industry: production of parts for kitchen equipment, such as rollers in mixers. Machining of decorative furniture elements.
Summary
CNC turning is an advanced machining technology that, thanks to its precision, repeatability, and versatility, has become an indispensable element of modern industry. It enables the production of both simple and complex components from various materials, such as metals, plastics, and composites, meeting the highest quality standards. Thanks to process automation and computer control, CNC turning ensures optimal use of materials, error minimization, and faster order completion. This technology finds applications in many industries, from automotive and aviation, through electronics and medicine, to the production of everyday objects, making it the foundation of modern industrial production.
CNC turning – contact us
At RADMOT, we offer CNC milling services, CNC turning services, as well as many additional services, including washing, aluminum anodizing, laser marking and assembly. We have at your disposal over 80 modern machines in our machine park, all from renowned manufacturers. Download the presentation and check on which machine tools we produce CNC turned parts and CNC milled parts.
Contact us and tell us what you need. We have been providing CNC services for almost 40 years. Our valuation is completely free. And if you're in doubt about which technology will work best for you, our expertise is at your service.
