Determining Coordinate Axes
Determining Axis Directions – The Right-Hand Rule
The direction of machine axes is determined using the right-hand rule. If you hold your index finger, thumb, and middle finger perpendicular to each other:
- Your middle finger represents the Z+ axis,
- Your index finger represents the Y+ axis,
- And your thumb represents the X+ axis.
The negative directions of the X, Y, and Z axes are simply the opposite of these indicated directions. Additionally, the Z axis is always aligned along the tool's rotation direction, and the positive Z direction is from the workpiece toward the tool.
Figure (2) – Directions of X, Y, and Z axes based on the right-hand rule.
To determine the direction of rotary axes A, B, and C, hold your right hand so that your thumb points in the positive direction of the X, Y, or Z axis respectively. Then, the curled direction of your remaining four fingers (in a fist-like position) indicates the positive rotational direction of the A, B, and C axes.
The negative directions of the A, B, and C axes are opposite to the directions indicated by this rule.
Figure (3) – Directions of A, B, and C rotary axes based on the right-hand rule.
Updated 4 days ago