This website requires JavaScript.

What Is The Difference Between Additive Manufacturing And Subtractive Manufacturing?

Blog  /  What Is The Difference Between Additive Manufacturing And Subtractive Manufacturing?

What Is The Difference Between Additive Manufacturing And Subtractive Manufacturing?

Jan 02,2024

Additive Manufacturing vs. Subtractive Manufacturing: A Comparative Overview


addtive manufacturing compared with subtractive manufacturing


What is Additive Manufacturing?


Additive manufacturing, often known as 3D printing, is a manufacturing technique that involves layering material to create three-dimensional things. The process begins with a computerized 3D model of the item divided into several cross-sectional layers. The final product is then created by sequentially printing or depositing these layers utilizing different methods.


Additive manufacturing is appropriate for a variety of engineering and industrial applications such as prototyping, manufacturing tools, and casting patterns, as well as short-run, bridge production, and bespoke manufacturing of final items. With any other manufacturing method, creating complicated designs would be unfeasible or prohibitively expensive. However, 3D printers allow a very high degree of design freedom.


TechniqueProcess

Selective Laser Sintering (SLS)In SLS, a high-power laser selectively fuses powdered material (such as plastics, metals, or ceramics) layer by layer, creating a solid object.
Digital Light Processing (DLP)Similar to SLA, DLP uses a digital light projector to selectively cure a vat of liquid resin layer by layer.
Stereolithography (SLA)

SLA uses a vat of liquid photopolymer resin that is selectively cured by a UV laser, solidifying the material layer by layer to form the object.

Fused Deposition Modeling (FDM) or Fused Filament Fabrication (FFF)This method involves extruding a thermoplastic filament through a heated nozzle, which deposits the material layer by layer to create the object.



Pros and Cons of Additive Manufacturing



Pros of Additive Manufacturing


· Design Freedom: Highly complex geometries and elaborate designs that may be difficult or impossible to achieve with traditional manufacturing methods can be produced thanks to additive manufacturing. This makes more inventiveness and ingenuity in design possible.


· Customization: Products can be made with additive manufacturing that can be personalized and customized. Customized and unique goods can be produced by adjusting each layer to satisfy specific needs.


· Decreased Material Waste: Compared to subtractive manufacturing techniques, additive manufacturing is intrinsically more environmentally friendly. Because only the material required is used, it reduces waste production, material costs, and environmental effects.


Cons of Additive Manufacturing


· Limited Material Selection: Compared to subtractive manufacturing, the variety of compatible materials for additive manufacturing is still more narrow. It's possible that certain high-performance metals or specialized materials won't be suitable for 3D printing.


· Surface Finish and Quality: Parts made using additive manufacturing techniques might not have as smooth or accurate a surface finish as those made using subtractive manufacturing techniques. It can need more post-processing processes to get the appropriate level of surface quality.


· Size Restrictions: The dimensions of the 3D printer determine the maximum size of objects that can be manufactured using additive manufacturing. With today's additive manufacturing methods, it might not be possible to manufacture enormous objects on a large scale.



What is the Subtractive Manufacturing Process?


In subtractive manufacturing, also referred to as machining or milling, the material is removed from a solid block or workpiece to mold it into the required shape. Starting with a solid block of material, the desired shape is sculpted by carefully removing material with a variety of cutting tools.


TechniqueMaterials
CNC machining (turning, drilling, boring, milling, reaming)

Hard thermoplastics, thermoset plastics, soft metals, hard metals (industrial machines)

Electrical discharge machining (EDM)Hard metals
Water jet cuttingPlastics, hard and soft metals, stone, glass, composites

Laser cuttingThermoplastics, wood, acrylic, fabrics, metals (industrial machines)


Pros and Cons of Subtractive Manufacturing



Pros of Subtractive Manufacturing


· Comprehensive Material Selection: Subtractive manufacturing allows manufacturers to choose materials from a variety of sources, including metals, polymers, wood, and composites.


· Precise and Accurate: The extreme precision and accuracy of CNC machines, which are utilized in subtractive manufacturing, enable complicated geometries and tight tolerances.

· Surface Finish: By producing superior surface finishes right out of the machine, subtractive manufacturing eliminates the need for a lot of post-processing.


· Scalability: Subtractive manufacturing techniques are frequently appropriate for large- and small-scale production, which qualifies them for part mass production.


Cons of Subtractive Manufacturing


· Design Restrictions: Complex geometries or difficult-to-machine interior features may not be produced with subtractive manufacturing techniques.


· Material Waste: When surplus material is machined away during subtractive production, a substantial amount of material waste is produced. The environmental effect and cost of materials may increase.


· Longer Lead Times: Compared to additive manufacturing, subtractive manufacturing processes may require more time for setup, machining, and the acquisition of materials.



When to Use Subtractive and Additive Manufacturing?


The choice between additive and subtractive manufacturing is based on the materials needed for the project, the desired level of design complexity, the production volume, and the particular requirements of the project. Sometimes the best course of action is to combine the two approaches, making use of each one's advantages to accomplish the goal.


Subtractive manufacturing procedures are our preference for several reasons. As an illustration, consider CNC machining, which is excellent at obtaining tight tolerances and great precision.  Your project calls for exact measurements, specific features, or tight tolerances, subtractive manufacturing can be the better option. We can use it with many materials, such as composites, metals, polymers, and wood. If your project calls for particular materials with well-established qualities, subtractive manufacturing offers more choices. Also, because subtractive manufacturing is efficient and can use numerous machines at once, it is frequently more suited for large-scale production. Subtractive manufacturing may be more affordable if you need to make numerous similar items. Additionally, if your product requires a smooth surface finish or specialized surface treatments, subtractive manufacturing processes such as milling or grinding can produce the needed results more effectively.


On the other hand, additive manufacturing excels at constructing complicated geometries and elaborate designs that would be difficult or impossible to produce with subtractive production. Additive printing provides design freedom and flexibility if your project contains complicated structures or internal details. Moreover, with the use of additive manufacturing, strong, lightweight structures with optimized interior geometry may be produced with less material used. This is advantageous in sectors where weight reduction is crucial, such as the aerospace and automobile industries. Also, fast iterations and design modifications are possible with additive manufacturing, which eliminates the need for costly tooling, making it the perfect method for rapid prototyping. Additive manufacturing produces prototypes more swiftly if you need to develop and test them quickly. In addition, low-volume production and on-demand manufacturing are good uses for additive manufacturing. Additive manufacturing can be a cost-effective solution if you need to make small numbers of customized items without buying expensive tooling or inventory.


Conclusion


In conclusion, the primary distinction between additive and subtractive manufacturing is found in their core processes. While subtractive manufacturing entails taking material out of a solid block to generate the required shape, additive manufacturing, commonly referred to as 3D printing, builds objects layer by layer by adding material.


Every manufacturing technique, both subtractive and additive, has advantages and purposes. Various considerations, including design complexity, material selection, customization requirements, production volume, and time restrictions, influence the decision between the two approaches. Both strategies are combined in many sectors to take advantage of their unique advantages and produce the best outcomes.