At 3D Hubs, we’re taking away the pain for engineers to cost-effectively source custom parts. This is why we’re now introducing instant Design for Manufacturing (DfM) feedback for CNC parts. The new DfM tools will analyze your parts for important issues that can make them unmachinable or more expensive to manufacture.

How to Access It

Head to the 3D Hubs platform and select CNC machining as your technology. Start building your instant quote by uploading your CNC parts and access the DfM tools by checking the manufacturability next to the 3D viewer of your part. The following short video shows you exactly how to access the DfM tools, step by step.

The DfM Feedback In-Depth

Hard to Remove Material

The DfM tools will instantly detect volumes of material that are difficult to reach with a standard 3-axis mill and therefore make you part more expensive to manufacture. This gives you the chance to update your design before sending your parts for manufacturing.

An example of such volumes are “undercuts”. Undercuts are features that cannot be machined with standard end-mill cutting tools, no matter how the part is rotated. Undercuts can be machined using special T-shaped, V-shaped or lollipop-shaped cutting tools. However, for non-standard geometries, you'll need to use a 5-axis CNC mill or manufacture the tools from scratch. This will drive up the cost of your parts drastically.

Sharp Internal Corners

If not stated otherwise in your technical drawing, any detected sharp internal corners on your part will be machined with a 2 mm radius to keep the cost of manufacturing as low as possible.

When you upload your parts, our DfM tool will search for any internal corners that are not machinable with standard end-mill tools, due to the diameter of the cutter. To machine these features, a more expensive process, such as EDM, must be used. If required for your part, you can make EDM an explicit requirement in your technical drawing.

Thin Walls

Our DfM tools will also detect walls that are thinner than a material-dependent threshold, and therefore require time consuming cutting routines or alternative manufacturing processes, that increase the cost of your parts. An update of the design is therefore highly recommended to keep costs lower.

Thin walls can be unmachinable, as these features are likely to break during manufacturing due to the cutting forces. For CNC machining the recommended minimum wall thickness is 0.8 mm for metals and 1.5 mm for plastics. All features must have a height to width aspect ratio smaller than 4.

Walls that exceed these guidelines will be manufactured using special and more expensive tooling or EDM.


Get instant DfM feedback on your CNC parts by uploading them to the 3D Hubs platform.

Learn more about how to optimize your design for CNC machining with 15 practical design tips in the CNC Cost Reduction Check List.