While both are computerized fabrication processes, CNC machining and 3D printing differ significantly in their processes, materials, production capabilities, and final product outcomes. CNC machining is a subtractive manufacturing method that uses pre-programmed cutting tools to shape parts and components from a piece of stock material. Conversely, 3D printing uses additive measures to create pre-programmed shapes from melted plastic, resin, and metal. Both methods are automated and highly dependent on computer software but are fundamentally different processes, only occasionally producing similar results in specific applications.
To understand the basic difference between CNC machining and 3D printing, it is important to understand the difference between additive and subtractive manufacturing processes.
Additive manufacturing, as its name implies, is based on the addition of material to create a part or component. In most additive manufacturing cases, such as in 3D printing, parts are created from melted material. The melted material is layered and shaped according to pre-programmed specifications.
Subtractive machining begins with a large stock of raw material; this material is cut or milled away in fine amounts, producing the final, desired shape. Unlike additive processes, subtractive machining does not require melting and curing of raw materials so it can be used on a greater variety of materials.
MATERIALS UTILIZED FOR CNC MACHINING & 3D PRINTING
Due to their different fundamental fabrication methods, CNC machining and 3D printing have different material capabilities. Specifically, additive 3D printing has more functional limitations than subtractive CNC machining.
CNC machining can be used to create parts and components from a wide range of materials, including:
Thermoplastics
Acrylic
Fiber in-layered composites
Machining wax
Modeling foam
Metals and metal alloys
Wood
Graphite
Glass
Quick production. CNC machining is a much faster production process than 3D printing, especially for higher-volume production.
Material versatility. CNC machining can be used to fabricate parts from a much wider range of materials.
Part durability. Material versatility means that CNC machining can produce parts from much stronger and more durable materials.
Superior precision. CNC machining offers exceptional precision and accuracy when compared to 3D printing.
Easy Customization. CNC machining is easily customized for special parts and components.
While 3D printing may be useful for small batches, prototypes, or parts that do not require strict precision or strength, CNC machining remains a superior manufacturing method for most production runs. The CNC machining process is faster, more versatile, more precise, and more easily customized than 3D printing.
3D printing is much more limited in its range of operational materials since the material must be able to melt into a liquid state to print to the specifications. The vast majority of 3D printing uses plastic resins, though the latest technology has expanded material options for certain 3D printer types. Materials available for 3D printing include:
Thermoplastics
Nylon
Wood filaments
Metal filaments (carbon, titanium, steel)
Photopolymers
Wax
Although 3D printing can produce some metal or wood-based products, the end products have reduced durability and temperature resistance than their extruded and machined equivalents.
Fast turn-around. 3D printed parts have very little setup time and custom programming to operate and a small batch of parts can ship within 2-3 business days.
Cleaner production. 3D printing is an overall cleaner process than CNC machining.
Reduced waste. Since it is an additive process, 3D printing produces notably less energy and material waste. The little waste that is produced comes from supportive materials used in the printing process.
Fast Customization. 3D printing can create extremely complex parts quickly. This is especially ideal for prototypes and small-batch jobs. Since complicated geometries are built in rather than cut out, no tooling needs to reach internal features; this expands the potential complexity of printed parts.
Pro-Type Industries provides high-quality CNC machining services for a wide variety of industries and applications. With almost 50 years of experience in fabrication and manufacturing, Pro-Type has built an international reputation for superior manufacturing. For more information on our exceptional CNC machining capabilities, contact us today.