The Evolution of CNC Vol. 1:CNC turning
A sneak peek at this issue:
The ballpoint pen in your hand, a component of a car’s drive shaft, and those precision nuts found everywhere—when examined closely, they all exhibit an extremely precise rotational symmetry. So, what exactly enables these parts to be machined with such perfect roundness and such precision? Today, we are going to lift the veil on the mystery behind this process: CNC turning.
What is CNC turning?
If we were to compare manufacturing and machining to artistic creation, then CNC turning would be akin to “pottery thrown from a metal slab”.
The workpiece, clamped securely in place, is spinning at high speed; yet the cutting tool, with its hardness and sharpness, much like our own nimble fingers, moves along the contour of the workpiece to cut away the material; excess metal is removed bit by bit, resulting in a smooth, standard cylinder, a smooth, standard cone, a smooth, standard thread, and even a smooth, standard sphere.
CNC turning has three key characteristics:
However, CNC turning has significant limitations; at its core, it is a “rotational machining” process and is therefore only capable of machining symmetrical shapes such as circles and cylinders.Rotating componentsThese are machined; however, if the workpieces are irregularly shaped, other CNC processes must be employed in conjunction with this one.
Three key parameters
To produce parts that meet specifications, three key parameters must be carefully controlled in CNC turning.
1. Rotational speed: how fast the workpiece rotates
When rotating the raw material, the speed must not be too fast, nor too slow. If the rotational speed is too fast, the workpiece is likely to overheat and become deformed; if the rotational speed is too slow, machining efficiency will be very low and the surface finish will be rough.
Adjustments are usually made according to the material and dimensions of the workpiece. For example, when machining aluminium alloys, the rotational speed can be set slightly higher, whereas when machining hard steel, the rotational speed needs to be slightly lower.
2. Feed rate: the “speed” at which the tool moves”
The quantity used to indicate the distance travelled by the cutting tool per revolution is known as the feed rate. If the feed rate is too high, significant tool marks will appear on the surface of the workpiece; if the feed rate is too low, the machining speed will be slow, which in turn will affect efficiency.
3. Tool material: the “scalpel” of machining”
Provided the correct tool material is selected, machining can be carried out efficiently and accurately. There are generally three common types of tools, and each of the various materials corresponds to different machining requirements:
Applications of CNC turning
It is precisely because the “circle” has been perfected to such an extent that turned products are virtually ubiquitous in our daily lives; that is the situation.
Parts produced by CNC turning include drive shafts for motor vehicles, brake discs and shaft-type components for engines. The precision of these parts has a direct impact on the vehicle’s safety and stability whilst driving; it is therefore essential to ensure that tolerances are accurate and free from error to prevent issues such as loosening or wear.
Electronics industry
Electronic devices such as computers, headphones and the mobile phones we use every day contain many precision CNC-turned parts, such as the screws in mobile phones and the metal tubes in headphones. These components are small in size yet require a high degree of precision; CNC turning enables them to be produced with both compact dimensions and high accuracy, without affecting the normal operation of the electronic devices.
Basic hardware components such as screws, nuts and bolts are mostly manufactured in bulk using CNC turning. It is precisely because of CNC turning that these components can be produced to uniform specifications and achieve a tight fit.
CNC Turning Solutions
If you have any requirements for CNC turning—whether for prototyping or mass production—Zhemi Technology can tailor its services precisely to your needs.
Coming up next
In this issue, we’ve unlocked the secrets of CNC turning
Although it excels at machining rotary parts, it is “at a loss” when it comes to irregular surfaces”
Those irregular, irregularly shaped parts and complex curved parts
What manufacturing process is used?
Chinese 
Japanese 
English 
German 
Finnish 
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