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FITTER - CITS

• CNC Machine Axis designation (By Right Hand Thumb Rule):
The right-hand thumb rule is commonly used in engineering and physics to determine the direction of various
vectors. When applied to CNC machine axis designation, the rule helps establish the orientation of the axes
based on the movement of the machine.

Here’s how the right-hand thumb rule is typically applied to CNC machine axes:
1 X-Axis (Horizontal Direction):
• Extend your right hand with your thumb pointing to the right (parallel to the X-axis).
• Curl your fingers towards the positive direction. Your fingers will point in the direction of positive X-axis
movement.
2 Y-Axis (Vertical Direction):
• Extend your right hand with your thumb pointing upwards (parallel to the Y-axis).

• Curl your fingers towards the positive direction. Your fingers will point in the direction of positive Y-axis
movement.
3 Z-Axis (Depth or Vertical Direction):

• Extend your right hand with your thumb pointing upwards (parallel to the Z-axis).
• Extend your index finger forward (parallel to the X-axis).
• Extend your middle finger to the right (parallel to the Y-axis).
• Your thumb, index finger, and middle finger should form a right- handed coordinate system.
• The direction in which your thumb points indicates the positive direction of the Z-axis (depth or vertical
movement).
- Right hand thumb rule :
- Middle finger = ‘z’ axis

- Index finger = ‘y’ axis Thumb finger = ‘x’ axis
• Axis Used In CNC Lathe:
- X-axis = cross slide movement
- Z-axis = carriage movement

- Linear axis/primary axis: X,Y,Z
- Supplementary axis :U,V,W
- Rotary axis: A, B, C
Here’s a breakdown of the axis designations commonly used in CNC machines:

1 Linear Axes (Primary Axes):
• These are the main axes responsible for linear movement along the X, Y, and Z directions.
• The X-axis typically represents horizontal movement, the Y-axis represents vertical movement, and the Z-axis
represents depth or axial movement.
• Linear axes are essential for positioning the cutting tool or workpiece accurately in three-dimensional space.
2 Supplementary Axes:
• These axes are additional linear axes that provide supplemental movement in directions other than X, Y, and
Z.
• They are designated as U, V, and W axes.
• Supplementary axes are used for complex machining operations that require additional degrees of freedom
beyond the primary axes.

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