CNC machining starts with a block of material and shapes it with a rotating tool. Following the program, it carves away excess until you have the finished product. This is the subtractive method because it’s taking away material.
3D printing layers on material in the additive method that builds your design. Both ways have pros and cons in terms of durability, precision and use of materials.
CNC machining works with a variety of materials. They can use:
CNC machines have heating systems that can manage heavy materials. These materials are used to build substantial parts for engines, aircraft and other machines. They need to be exact, dependable and durable. The cutting tools for the design might have to switch, but most tools are standardized to fit any CNC machine.
3D printing doesn’t have this variety, using materials like plastics or resins. They can’t produce items strong enough to withstand intense environments like airplanes or other machinery. Also, 3D printers can’t switch between materials. Certain 3D printers are for specific kinds of material.
3D and CNC Precision of Production
CNC machining is more precise and consistent than 3D printing because they have a higher tolerance for heat. 3D printers end up with distorted products when there’s too much heat. They can offer precision but cannot remain consistent. 3D printers are often regarded as more user-friendly than CNC machines, but when they malfunction, someone has to troubleshoot them because the fault means production of unusable products.
CNC and 3D Speed of Production
CNC is a faster solution than 3D printing. Automated CNC machines can work around the clock as long as they’re properly maintained. A project that could take CNC machining an hour would equate to a 3D printer taking hours to get the final product because it has to build the product layer by layer. A 3D printer’s pace might have to slow down during the process to get the design right. Different 3D printers could also be programmed with specific speeds that you can’t alter. It depends on the machine you use.
3D printed products also require work after they’re built. The products need to be washed, polished and sealed before people can use the product. This could extend prototype testing to a longer time period with a lot of waiting in between. 3D printers are also popular for smaller, custom-manufactured items. But if you have to wait for the item to be built and still do a lot of work post-print, you lose a lot of time before you can move the product.
Versatility of Machinery for CNC vs. 3D
CNC machines can produce fixtures, tools and custom-designed parts. They have a wide range of quality settings so you can make a prototype that has a rougher design in some areas and perfect in others so you can test that part.
When testing prototypes for a project, a CNC machine could quickly build a design so the developers can test it. 3D printers don’t have these kinds of options. It will slowly shape the design as it was programmed. Accuracy is key when constructing a final product, but when time is a constraint and you want to test some prototypes, 3D printers can slow down you and your project. Designs made for a CNC machine usually can’t be substituted with a 3D printer because the products are voluminous and it would take hours for a 3D printer to finish them.
Noise and Mess Produced by CNC and 3D
These differences relate to the subtractive and additive methods. CNC machining is much more noisy and messy than 3D printing because it uses a tool to cut away material. This creates noise and a lot of scrap metal or wood shavings. CNC machines cause a lot of vibrations, so they need to be in a space where they won’t bother anyone. 3D printing only uses the material it needs for the product. There’s little to no waste, and the printers don’t vibrate like a CNC machine.