3-axis milling is a common CNC (Computer Numerical Control) machining process where a cutting tool moves along three linear axes: X (left–right), Y (front–back), and Z (up–down). The workpiece remains fixed while the tool removes material to create the desired shape.

3 Axis Milling:

3-axis milling is the most common and fundamental form of CNC (Computer Numerical Control) machining. It uses a rotating cutting tool to remove material from a workpiece while moving along three linear axes.

1. What “3 Axes” Means

In a 3-axis milling machine, the cutting tool or table can move in:

X-axis – left ↔ right
Y-axis – front ↔ back
Z-axis – up ↕ down

👉 The tool cannot tilt or rotate during cutting; it stays perpendicular to the work surface.

2. How a 3-Axis Milling Machine Works

CAD Model Creation
- The part is designed in CAD software (SolidWorks, Fusion 360, CATIA, etc.).
CAM Programming
- Toolpaths are generated in CAM software.
- Parameters include:
  - Tool type and diameter
  - Spindle speed (RPM)
  - Feed rate
  - Depth of cut
G-Code Generation
- CAM software converts toolpaths into G-code.
- Example:G01 X50 Y30 Z-5 F200
Machining Process
- Workpiece is clamped to the table.
- Tool moves along X, Y, and Z axes to cut the material.

3. Main Components of a 3-Axis Milling Machine

a) Spindle

Holds and rotates the cutting tool
Speed typically: 1,000–20,000 RPM

b) Table

Holds the workpiece
Moves in X and Y directions (or sometimes the tool moves instead)

c) Linear Guideways & Ball Screws

Provide precise movement along each axis

d) Controller

Reads G-code and controls axis motion

e) Tool Holder & Cutting Tools

End mills, face mills, slot drills, ball nose cutters

4. Common Machining Operations

a) Face Milling

Produces a flat surface
Tool moves in X–Y plane

b) Slot Milling

Creates slots or keyways

c) Pocket Milling

Removes material inside a closed boundary

d) Contour Milling

Cuts external or internal profiles

e) Drilling & Boring

Holes machined along the Z-axis

5. Materials Machined on 3-Axis Mills

Metals: Aluminum, steel, stainless steel, brass, titanium
Plastics: ABS, nylon, PEEK
Composites: Carbon fiber, fiberglass
Wood & MDF

6. Advantages of 3-Axis Milling

✔ Simple machine design
✔ Lower cost than 4-axis or 5-axis machines
✔ Easy programming and setup
✔ High accuracy for prismatic parts
✔ Widely available and well supported

7. Limitations of 3-Axis Milling

✖ Cannot machine undercuts
✖ Limited access to complex geometries
✖ Multiple setups required for multi-side machining
✖ Longer machining time for complex parts