Shenzhen Alu Rapid Prototype Precision Co., Ltd.

Precision prototype machining is a subtractive manufacturing process where computer-controlled machines remove material from a solid block (workpiece) to create a highly accurate, functional part.

Unlike standard prototyping,"precision" machining focuses on achieving tight tolerances (oftenas low as 士0.005 mm or 士0.0002inches)and superior surface finishes.

The Step-by-Step Process

1. CAD Modeling (The Digital Blueprint)

The process begins with Computer-Aided Design (CAD) software. Engineers create a 3D model that specifies every dimension, thread, and fillet. For precision work, this model must account for the material's properties (like thermal expansion) and how it will be clamped during machining.

2. CAM Programming (Translating to Machine Language)

The CAD file is imported into Computer-Aided Manufacturing (CAM) software. An engineer uses CAM to:

a.Define the "toolpaths" (the exact route the cutting tool will take).

b.Select specific tools (end mills, drills, or lathing tools).

c.Set "speeds and feeds" (how fast the tool spins and moves through the material).

d.The software then generates G-code, the language the CNC machine understands.

3. Machine Setup & Calibration

This is where precision is won or lost. The machinist:

a.Secures the raw material (billet) using specialized jigs, fixtures, or vacuum tables.

b.Loads the required cutting tools into the machine's automatic tool changer.

c.Zeroes the machine: Calibrating the X, I, and Zaxes so the machine knows exactlywhere the material starts.

4. The Machining Phase

The CNC machine executes the G-code. Depending on the complexity, this might involve:

a.Milling: Rotating tools cut the part while it stays relatively stationary.

b.Turning (Lathe): The part rotates at high speed while a stationary tool shapes it (ideal for cylindrical parts).

c.Multi-Axis Machining: 5-axis machines can move the tool and the part simultaneously, allowing for complex "undercuts" and organic shapes without manual repositioning.

5. Inspection & Quality Control (Metrology)

Because it is a "precision" process, the part is measured against the original CAD file using:

a.CMM(Coordinate Measuring Machines): Probes that map the part's surface to withinmicrons.

b.Optical Comparators: Using light and magnification to check profiles.

c.Surface Profilometers: To ensure the surface roughness(Ra) meets the spec.

6. Secondary Finishing

If the "as-machined" finish isn't enough, the prototype undergoes:

a.Bead Blasting/Polishing: For aesthetic or functional smoothness.

b.Anodizing/Plating: For corrosion resistance or color.

c.Heat Treatment: To harden the material for functional testing.