CNC machining services are frequently requested by our customers when looking to fabricate complex shaped metal parts. So how to process these structurally complex parts? Well there are generally 2 processes: Milling and Turning.
Milling and turning. Both are CNC machining methods, but they are not the same. CNC stands for Computer Numerical Control and refers to the fact that CNC milling and CNC turning use a computer system to guide the cutting machinery. Good CAD-CAM software can easily convert a 3D model into readable code for a CNC machine. This determines tool use and movement, cutting paths, etc. While our engineers can make a decision about the proper operation of a part, it can be interesting to know the differences.
What is the difference between CNC milling and turning?
The short answer is this - CNC milling uses rotating tools, while CNC turning uses rotating parts for cutting. Therefore, the two use different techniques to create parts. While milling machines create complex parts from blocks of metal by removing excess material, turning is typically used for cylindrical parts such as shafts.
What is cnc machining milling?
Let's start with milling. The first is the more traditional three-axis CNC milling machine. The tool can move in 3 directions of X, Y and Z axes.
While this places some constraints on the geometry of the part, it is sufficient for most jobs that require milling. A wide range of milling tools can provide different cutting methods, such as end milling, face milling, hollow milling, etc. Multi-axis milling allows 4 or more axes, including tool and table rotation. This provides additional flexibility. 5-axis milling machines are the most common of these and are capable of making almost anything that can be made with milling.
The size of the initial block is usually larger than the general size of the final part. Therefore, each side can be precision milled. Tolerances are very tight, so a good surface finish is easy to achieve.
What is cnc machining turning?
As mentioned earlier, CNC lathes are mainly used to manufacture cylindrical parts. These can be shafts, custom hollow tubes, cones, or anything else that requires turning services.
While 5-axis machining can also create cylindrical parts, turning is more efficient, and the hourly rates for these machines are lower. Chucks hold the stock material (usually a round bar) in place. The chuck rotates at high speed together with the spindle. Maximum speed or RPM is machine dependent.
The single point cutting tool is mounted on the turret. The turret moves in and out of the workpiece as it rotates, allowing the tool to make contact with the metal to cut.
This highly precise machining method allows tight tolerances to be achieved. This is why limits and fits are often used with hole-based systems, as it is easier to achieve the required precision on the shaft.
In conclusion
While the two are often lumped together under the same term - CNC machining - they are not the same. Still, they complement each other perfectly to produce high-precision parts.
For example, a CNC mill may be used to add features after turning a shaft.
Since both are widely used in manufacturing, it is wise to differentiate between the two.