Subtractive manufacturing differs from additive manufacturing in that it removes material to produce a part of the desired size. First of all, there are many types of subtractive manufacturing methods, just like additive manufacturing includes multiple processes. For example, you may have heard the term "CNC machining". It is an acronym for Computer Numerical Control and covers material removal techniques based on a digital program that controls a machine tool, such as drilling, turning, milling, or boring that we often talk about. CNC machining is now compatible with a wide range of materials, from plastics to metals.
What is CNC machining?
CNC machining consists of several processes, turning and drilling techniques are introduced for the first time, and the machining process is for moving parts on rotating axes. The energy required to machine a part is provided by the motion of the part itself. These methods make it possible to manufacture any part that is modeled on rotation. Specifically, it is a 2D drawing that is infinitely replicated along the axis of rotation, resulting in a 3D model. Despite their different names, turning and boring are very similar because they both use the same principles. The main difference is that while boring works on the inside of the part, turning works on the outside, allowing machining of wood, metal, and certain plastic materials. There is also a type of milling. With extreme precision, the ability to create parts with internal cavities, and the ability to machine parts, milling is an extremely important means of manufacturing. This technique uses a milling cutter to cut the material laterally. This means that when the cutter is in the material, it can move vertically and remove material along its path. Milling is compatible with many materials due to its suitability for various tasks and material processing. Nonetheless, this method has some drawbacks that reduce its ease of processing. For example, the machining of a part is often divided into several steps/operations, which all require periodic tool changes.
The tools used for drilling and milling are very similar but should not be confused. Drilling is only used to make round holes with a drill bit. While milling offers greater manufacturing freedom, especially allowing you to make holes or shapes that are larger in diameter than themselves, drilling allows you to make holes equal to the diameter of the drill. Despite its many advantages, milling is much slower than drilling when punching, which is why drilling is better for making several identical cuts in a row. While CNC machining encompasses many techniques, subtractive manufacturing is not limited to these. Other methods, such as cutting, are also used by many industries.
Disadvantages and advantages compared to additive manufacturing
Key benefits of subtractive manufacturing technology
1, Provide high dimensional accuracy. Subtractive manufacturing allows parts to be manufactured at room temperature, avoiding the dimensional accuracy issues associated with the work (shrinkage) of the material. To ensure dimensional accuracy in subtractive manufacturing, the environment must be controlled.
2. There is a wider range of compatible materials. It is possible to perform subtractive processing of metal, plastic, or wood parts on the same machine.
Disadvantages of subtractive manufacturing processes.
1. Compared to 3D printing, different subtractive manufacturing production methods leave a large amount of scrap, while additive manufacturing is attractive because it only uses the required amount of material.
2. Does not provide the freedom of manufacturing that 3D printing does. A printable part sometimes needs to be manipulated multiple times, using different machines, and assembled into multiple parts before it can be reproduced by subtractive manufacturing.
How does subtractive and additive manufacturing complement each other?
Due to the different technical approaches of subtractive and additive manufacturing, they are mostly used in complementary ways. Since 3D printing technology started to grow strongly, it is most often used for prototyping. With the technical advantages of 3D printing itself, it allows multiple parts to be manufactured quickly and at a low cost, thus offering the possibility of different iterations.
For the production needs of parts with defined shapes and materials, it is possible to use subtractive manufacturing methods for mass production. Some processes, such as laser cutting and water jet cutting, can design a large number of parts in a very short period of time. However, other methods, such as CNC machining, can be very time-consuming. This technique requires an important programming step, as well as the necessary labor costs. Today, CNC machining is mainly used for the manufacture of injection molds, which is a molding manufacturing technique.
Also, while subtractive manufacturing can repair objects, 3D printing offers more possibilities in this area. One example is the directed energy deposition (DED) process, which can be used to repair metal parts without having to alter them. Specifically, the technology enables the addition of material to existing parts, thereby avoiding unnecessary assembly or replacement of large parts. On a larger scale, 3D technology allows the reproduction of problematic or time-worn parts, all on-demand and in small batches. Users can repair their parts rather than throw them away and minimize their impact on the environment.
Despite differences and processes, subtractive and additive manufacturing often go hand in hand. Due to their respective characteristics, these two types of fabrication complement each other to rapidly create precise parts never imagined before. To combine these manufacturing technologies, several investment projects have been created, such as Hybrid Advanced Manufacturing. Integrating various technologies provides the design freedom of additive manufacturing and the precision of subtractive manufacturing.
JR is a company that integrates subtractive manufacturing and additive manufacturing and can help customers solve the post-processing process of 3D printing.
The following is the website of our company, please feel free to contact us and inquire.
3D printing service website: www.china-3dprinting.com
CNC machining website: www.elite-machining.com