Getting Started with CNC Machining

Whether you’re prototyping a new product or producing low-volume parts, CNC machining offers accuracy, repeatability, and excellent material properties. Here’s a quick primer to help you decide if CNC is right for your project.

What is CNC machining?

Computer Numerical Control (CNC) uses programmed toolpaths to remove material from solid stock (like aluminium, steel, or plastics). Compared to 3D printing, CNC parts are typically stronger, have tighter tolerances, and better surface finish.

When to use CNC

• Functional prototypes that need real material properties
• Low-volume production where tooling for injection molding is overkill
• Tight tolerances and flatness requirements
• Heat- or load-bearing components where printed parts aren’t suitable

Typical tolerances and materials

• Common metals: 6061-T6, 7075, 304/316 stainless, brass
• Plastics: Delrin (POM), ABS, Nylon, PETG, Polycarbonate
• Baseline tolerance: ±0.10 mm is common; tighter specs are possible with clear datums

The basic workflow

1. Share a 3D model (STEP/IGES) and a brief tolerance/finish note
2. DFM review to flag thin walls, deep pockets, and tool access
3. CAM programming to generate safe and efficient toolpaths
4. Machining and inspection with calipers or CMM where required
5. Finishing options like deburr, bead-blast, or anodising

Tips for better quotes

• Add a simple drawing with critical dimensions and tolerances
• Specify threads, chamfers/fillets, and any critical surfaces
• Tell us quantities and deadlines to optimise setup vs. unit cost

CNC vs. 3D Printing (quick take)

• CNC: stronger parts, better finish, excellent dimensional accuracy, wider material choice
• Printing: faster for complex internal geometries, often cheaper for very low loads

---

Have a part in mind? Send your model for a quick DFM check and a quote.