Designing parts for CNC machining requires consideration of various factors to ensure manufacturability, cost-effectiveness, and functionality. This guide provides key principles and tips for optimizing your designs for our CNC services.

Tolerances

Specify appropriate tolerances. Standard tolerances are generally more cost-effective. Tighter tolerances increase machining time and cost. Clearly indicate critical dimensions that require tighter control.

Wall Thickness

Avoid excessively thin walls, as they can be difficult to machine and may warp. Minimum wall thickness depends on the material and part geometry, but generally aim for at least 0.8mm for metals and 1.5mm for plastics.

Internal Radii

CNC cutting tools are round, so internal corners will always have a radius. Design with the largest possible internal radii, as smaller radii require smaller tools and more machining time. A common rule of thumb is that the radius should be at least 1/3 of the cavity depth.

Hole Design

Standard drill sizes are more economical. For deep holes (depth-to-diameter ratio > 6:1), consider potential difficulties in chip evacuation and tool breakage. Clearly specify if holes are threaded and provide thread specifications (e.g., M6x1.0).

Feature Design

Avoid undercuts where possible, as they require special tooling or multi-axis machining, increasing cost. Simplify complex geometries if functionality is not compromised. Consider the accessibility of features for cutting tools.

Material Selection

Choose materials based on the desired mechanical properties, cost, and machinability. Softer materials like aluminum are generally easier and faster to machine than harder materials like stainless steel or titanium. Refer to our CNC Materials page for options.

Text and Lettering

If text or logos are required, opt for engraved (recessed) features rather than raised ones, as they are easier to machine. Ensure font sizes and line thicknesses are large enough to be clearly machined.

By following these guidelines, you can improve the manufacturability of your CNC parts, reduce costs, and shorten lead times. Our DFM (Design for Manufacturability) feedback on our platform can also help identify potential issues.