About Motion Axis Settings
Motion Axis settings control the motion axes in your mechanism. Use the Motion Axis dialog box options to set the:
• current position of the bodies joined by the motion axis connection
• geometric references used to define the zero position of the motion axis
• position at which the motion axis will regenerate
• limits to the motion allowed by the motion axis
• friction force resisting the axis motion
You cannot define motion axis settings for a ball joint. In addition, you cannot edit a rotational motion axis that belongs to a multiple-rotation DOF connection such as a 6DOF or general connections.
The settings you define in the Motion Axis dialog box are used to perform analyses and when dragging the model. The zero position definition is used when you define a servo motor or for the unstretched length of a spring, that is, before any motion begins.