What is CNC machining?
CNC (Computer Numerical Control) machining is a subtractive process that uses precision tools to cut away material to produce the desired part or product. The software controlled tool head is far more precise than any human could ever be, allowing for exact replications.
Who is CNC machining for?
CNC machining is better suited to working with metals than 3D printing, although it is also possible to 3D print metal. Other materials often used with CNC machining include wood, foams, and wax, and it should be noted that different tools are required for each type of material. CNC machining is slower to set-up than 3D printing, but once prepared the subtractive method is significantly faster than the additive method employed by 3D printing. CNC machining is also generally more accurate than 3D printing, with tolerances as low as 0.001 mm. The downside of CNC machining is that highly complex designs may not be possible to produce due to tool access issues. In summary, CNC machining is best for relatively simple designs using traditional materials like metal or wood, and where a high level of precision is required.
The process for CNC machining is somewhat similar to 3D printing. As with 3D printing, a detailed CAD drawing is necessary, which is analyzed by a technician and imported into specialized software. In the case of CNC machining, at ProtoFab we convert files into the .nc format and import into Mastercam. During the programming phase, the technician has to decide which type of cutting tool to use based on the materials being used and any specific challenges caused by the shape. Once the tools are ready and the programming is complete, the cutting process can begin. Both CNC milling and CNC turning are available at ProtoFab. Milling is the method used for regular parts, and turning is used for parts with cylindrical features. Once cutting is complete, each part is taken to post-production where the finishing process begins.