Rotary axes and direction of rotation

The following figure shows the positive direction of rotation of rotary axes. The base is a right-handed coordinate system. If the rotation is counterclockwise with look at the arrowhead of the coordinate system axes, the rotation is called positive. If the rotary axis is rotating around the X axis, then it is called "A axis", with rotating around the Y axis "B axis" and so on. If not separately stated, these directions of rotation are used in the kinematic transformations with rotary axes involved.