CNC Machining

Computer Numerical Controlled (CNC) machining is used to cut reliable three-dimensional parts out of metal and plastic pieces. CNC machining uses lathes, routers, mills, drills and other equipment to produce industrial hardware products in a subtractive manner from metal or plastic.

Why use CNC machining

CNC machining works well for high precision, complex and repeatable processes (e.g., contour machining) not enabled by manual processes. Use it when you need:

• A process that can handle tight tolerances
• Access to a variety of production-grade materials
• Medium to high volume production runs at standard lead times
• Parts with excellent mechanical properties made from solid pieces of raw material

How CNC MACHINING Works

• A Computer Aided Design (CAD) model is loaded onto a Computer Aided Manufacturing (CAM) software. The tool paths are created based on the CAD model
• Once the tool paths are set, CAM develops a G-code, an international standard language to command the machine
• The machine cuts, mills or drills the raw material along the x, y, z, a and b axes to shape the final part

Everything from speed to coordination is carefully controlled and repeated throughout the CNC machining process.

Popular applications

Tooling

CNC machining is a popular method to manufacture injection molds. The process can make complicated cuts at various angles as long as the design has been coded accurately.

Niche manufacturing processes

CNC machines can be coded and built for specific processes to cut durable metal products that alternative processes can’t create.

Medium to high volume production

CNC machining is cost-effective for medium to high volume production, especially those in the hundreds or thousands. Injection molding is recommended for parts that need to be manufactured in especially high volumes.

Considerations for CNC machining

Proper design for manufacturing (DFM) practices will ensure your part will be seamlessly manufactured at desirable production times with an ideal look. First establishing your part dimensions is important because it will affect everything from material costs to production time. Larger parts generally require 5-axis milling whereas small to medium size parts can use 3-axis milling.

Fortunately, there are plenty of production-grade materials on the market, ranging from metals, thermoplastics and even wood. These materials exhibit great mechanical properties, thermal properties and isotropic behavior.

When to consider additive instead

We recommend substituting additive for CNC machining processes if you specifically want to avoid startup costs, are constrained by a materials budget or have a part with an advanced geometry.

If you are manufacturing a metal part, consider direct metal laser sintering (DMLS), a powder bed fusion process that layers powdered metals as raw material. The process works for high-value parts at low volumes and acceptable startup costs. DMLS uses the existing powder as a support, which will allow you to print complex geometries.

If you are prototyping a plastic part, explore fused deposition modeling (FDM). FDM is an extrusion process used to print complex shapes and internal components. Thanks to its popularity, a comprehensive plastic material library is also available.

Whether it’s making the most of CNC machining or exploring additive, contact our team to discuss your manufacturing needs.