Rapid Prototyping: When to Machine First and Cast Later

If you outsource custom aluminum, zinc or magnesium parts to China, you have two ways to validate a new design:

1. Machine directly from solid billet (CNC prototyping).

2. Skip prototyping, cut hard tooling, pray the part works.

Option 2 often ends in $20 k+ tool re-cuts and 6-week air-freight delays.

Option 1—machine first, cast later—lets you freeze the design before tool steel is cut, cutting engineering-change cost by 60 % and time-to-market by 4-6 weeks.

Below is the same 7-step workflow we use for 300+ American and European die-casting customers every year.

 1. DFM Review (24 h)

    - Review 3-D STEP/IGES for wall thickness, draft, under-cuts, parting line.

    - Suggest alloy: A380, ADC12, Zamak 3, AZ91D.

    - Predict shrink & porosity with MAGMAsoft® .

       ·  ☑ Tight geometric tolerances (<±0.05 mm) 

       ·  ☑ Deep internal threads or cross holes

       ·  ☑ Wall thickness <1.2 mm on zinc or <2 mm on aluminum

       ·  ☑ Living-hinge or snap-fit features

       ·  ☑ Pressure-tight to 10 bar (no impregnation wanted)

       ·  ☑ Anodizing Type III hard-coat final call-out

If any box is ticked, order CNC prototypes; do NOT cut tooling yet.

       ·  ☑ All tolerances ≥±0.15 mm

       ·  ☑ As-cast surface 3.2 Ra µm acceptable 

       ·  ☑ Draft ≥1° per side

       ·  ☑ No pressure test; decorative only

       ·  ☑ Annual volume >5 k pcs (amortize tool cost)

Project: 120 × 90 × 45 mm electronic housing, 356 g, A380

      ·  As-cast, shot-blast 120# glass bead

      ·  Powder coat (RAL/ Pantone) ≥80 µm, salt-spray 1 000 h 

      ·  Chem-film (Alodine 1200) for conductivity

      ·  Anodizing Type II 10-12 µm, Type III 25-50 µm

      ·  Wet paint, silk-screen, laser etch, EMI nickel plating

Full material certs, PPAP level 3, CMM report included.

      1. 3-D file (STEP) + 2-D PDF with tolerances

     2. Alloy & annual volume

     3. Surface finish & any post-machining

     4. Target EXW or FOB price

     5. Delivery city (Los Angeles, Hamburg, Sydney…)

Reply within 12 h with DFM, tool quote, unit price, lead-time.

      ·  CNC prototypes de-risk custom die-cast projects for overseas OEMs.

      ·  Freeze design before tool steel = 60 % cheaper engineering changes.

      ·  Partner with a China die-cast factory that owns both CNC and casting shops under one roof to keep IP secure and lead-time short.

Need a rapid prototype quote for your next aluminum or zinc die-cast part?

Email your drawing to lyy@fsqj-tech.com or click "Upload File" on the top menu. We answer in 12 h—always.