A well-designed CNC machined part is not only defined by its dimensions, toleranzen, und Material. The way a component is designed can have a major impact on machining time, tooling requirements, achievable tolerances, Oberflächengüte, Produktionskosten, and overall manufacturing reliability.

Hier Design für Herstellbarkeit (DFM) becomes important.

Design for CNC machining means creating a component that can be manufactured efficiently with available CNC equipment while still meeting its functional requirements.

A design that looks simple in CAD can become surprisingly expensive or difficult to machine if it contains unnecessarily deep pockets, extremely thin walls, scharfe innere Ecken, excessive tight tolerances, or difficult-to-access features.

In diesem Leitfaden, we explain the most important CNC machining DFM principles engineers and product designers should consider before sending a drawing or 3D model to a manufacturer.

What Is DFM in CNC Machining?

Design für Herstellbarkeit (DFM) is the process of designing a component with its manufacturing method in mind.

Für die CNC-Bearbeitung, DFM focuses on questions such as:

• Can the cutting tool physically reach the feature?
• Can the part be securely held during machining?
• Is the required tolerance realistic?
• Can standard tooling be used?
• Are the internal corners compatible with available tools?
• Are the walls thick enough to prevent deformation?
• Is the required surface finish achievable?
• Can the part be machined without unnecessary setups?
• Are the specified tolerances actually necessary?
• Can the component be inspected efficiently?

The goal is not to change the engineering function of the part.

The goal is to achieve the required function with a simpler, more stable, and more economical manufacturing process.

Why CNC DFM Matters

Two parts can have almost identical functions but dramatically different manufacturing costs because of their designs.

Consider two aluminum components.

Part A

• Standard tools
• Accessible features
• Moderate pocket depth
• Standard hole sizes
• Practical tolerances
• Two machining setups

Part B

• Very deep narrow pockets
• Extremely small internal radii
• Dünne Wände
• Non-standard holes
• ±0.005 mm tolerances everywhere
• Five machining setups

Both parts may perform the same function.

Aber, Part B can require:

• More expensive tooling
• Longer machining time
• Additional setups
• Specialized inspection
• More tool wear
• Greater risk of scrap

Good DFM reduces these unnecessary manufacturing difficulties.