目录
What Is CNC Turning?
In CNC turning machining, a cutting tool, which is a lathe or center that doesn’t move, works around and trims off the workpiece to your desired shape.
The workpiece rotates as the stationary cutting tool works on it to make an object. CNC turning makes an object by removing excess raw material from the workpiece to form a new object. Hence, it’s a subtractive manufacturing process.
CNC turning machines are best for making objects that need symmetry around a central axis. So it’s one of your best CNC options to make cylindrical parts like shafts, bushings, machine pins, and so on.
CNC Turning Processes
The processes involved in CNC turning include:
- Drilling new holes or enlarging already created holes.
- Parting: This refers to removing a section of the workpiece material to shape the component you are working on better.
- Facing: This means flattening the surface of a rotating workpiece.
- Threading: This means making internal or external threads on the workpiece material.
- Grooving: This refers to adding grooves into the workpiece by cutting into the outer diameter.
What Is CNC Milling?
CNC milling is the reverse of CNC turning. In CNC milling, the workpiece is stationary while the cutting tool with multiple axes rotates around the workpiece to machine a new object.
Like most manufacturers, you can also use the CNC milling procedure to make complex machine components.
Always keep in mind that CNC milling machines come in different numbers of cutting axes. However, you’ll mostly find 3-axis, 4-axis, or 5-axis CNC milling machines as they enable you to machine components more precisely.
CNC Milling Processes
The procedures done using the CNC milling machining technique are:
- Face Milling: Face milling is a procedure that involves cutting flat smooth surfaces that are 90⁰ perpendicular to the axes of the milling tool.
- Peripheral Milling: This process makes cuts on the machine components that are parallel to the axes of the CNC machining tool.
- Drilling: This process produces holes in machine parts.
- Pocketing: Like your pant pockets, this process removes a piece of material from the inside of a closed space.
- Engraving: Adding markings or text to a machine’s part.
Similarities Between CNC Milling and CNC Turning
Milling and turning are popular but very different CNC machining techniques, but since they share a machining system, they share many features too, and common similar features include:
1. Automation
CNC turning and CNC milling are both automated, and alone, they carry out many sub-procedures without any human input. Automating these machines means the procedures are consistent and accurate as they operate to make other machine parts.
2. Workpiece Material Similarities
From the several CNC techniques commonly in use, milling and turning are two of the most flexible. Because they are flexible, you can use them with different kinds of raw materials including metals, wood, plastics, and even composite materials.
3. Cutting Tool
CNC turning and milling machines both have cutting axes that make up the primary component of both machines. And although they have similar cutting tools, the design of these axes and the orientation of the workpiece are different for both techniques.
Key Differences Between CNC Turning and Milling
The major differences between the CNC turning and milling machining procedures include:
1. Mobility of Workpiece
During CNC milling, the piece you are working on doesn’t move from its position. For CNC turning, the workpiece is the only mobile component of the setup.
2. Cutting Tool Type
For CNC milling, there is more than one cutting axis, and these axes wrap and trim the workpiece from the outside. In contrast, CNC turning machining has one cutting tool, which shapes and cuts the raw material from the inside.
3. Chips
Because they are built differently, CNC milling will always yield chips that are not continuous. It’s easier to control CNC turning machines, so CNC turning machines can produce a wider range of chips, including continuous, fragmented, and discontinuous chips.
4. Complexity of Designs
CNC turning machines are better suited for making components with simple designs that you have to repeatedly do. CNC milling, in contrast, is better for more detailed designs, and geometric shapes. CNC milling machines have this advantage because of their multiple axes, which can do this at a time.
5. Material Type
CNC turning machines are versatile, and they can work with any kind of material, including softer plastics. CNC milling works better with tougher materials and tough plastics.
6. Machining Technicality
CNC turning machines are easier to operate by anyone because they have a single cutting tool and do not move.
CNC milling machines have multiple mobile axes for cutting, so to operate them, you’ll need more experience.
7. Cutting Technique
For CNC turning, the static cutting tool works on the workpiece continuously as long as the machine is turned on. For CNC milling, the technique of cutting is rather intermittent; that is, the cutting tool works on the piece, pauses, and continues in this manner.
8. Applications
CNC turning machines are great options for tubular components or components that have a hollow shape at any point. CNC milling, on the other hand, is a better option for manufacturing flat or irregular surfaces that need more details.
Examples of Materials Used in CNC Turning and Milling
Materials that are better suited for either CNC turning or milling include:
| CNC Turning Materials | CNC Milling Materials |
| Brass | Steel alloy |
| Stainless steel | Copper and its alloys including bronze and brass |
| Titanium | Exotic materials |
| Plastics like nylon, PTFE | Engineering plastics (e.g., PEEK, Delrin) |
So Is Your Best CNC Machining Bet CNC Turning or CNC Milling?
Knowing whether to use CNC turning or CNC milling in your manufacturing plants depends on many factors. Major factors that should affect your choice of CNC machine include what your entire project needs, the material type you’ll deal with, your targeted volume of production, your skill level, and, of course, what you prefer.
However, if you’ll be manufacturing simple tubular components and you need a high-speed CNC machining process, you should opt for CNC turning. It’s also easier to follow through.
But, if you’ll deal more with detailed designs, complex geometries and shapes, and custom one-off parts often, then you should opt for CNC milling.
The best option, though, is to combine both CNC turning and CNC milling machining procedures in your manufacturing plant to leverage their advantages.
Final Thoughts
CNC turning and CNC milling are essential CNC machining techniques and together, they give the best results.
To increase your productivity, ensure that you understand how both techniques work and where you can use them. That way, you’d also minimize costs and ensure that your manufacturing process is top-tier.
