A perpendicular axes joint is a five degree-of-freedom primitive constraint. The
constraint is imposed such that the Z axis of a reference marker on one body (Body 2)
remains perpendicular to the Z axis of a reference marker on the other body (Body 1)
connected by the joint. All three translations are free along with two rotations about the Z
axis of markers on both of the bodies defining the joint orientation. Joint primitives like
perpendicular axes joints may not have a physical existence. These types of joints can be
used to impose unique constraints where using a regular joint would not be possible.
The perpendicular axes joint needs two axes (Axis 1 and Axis 2) that are mutually
perpendicular and each belonging to Body 1 and Body 2 respectively.
-
If the Joints panel is not currently displayed, select the desired joint by
clicking on it in the Project Browser or in the modeling window.
The Joints panel is automatically displayed.
-
From the Connectivity tab, click Body
1 and pick a body from the modeling window, or double-click Body 1 to open the Model Tree (from which the desired body can be
selected).
Note: If the selected joint is a pair entity, first distinguish between the
Left and Right tabs in the
panel, and then edit the properties. When defining a pair joint, use pair
entities for Body, Origin, etc.
-
Similarly, click Body 2 and
select the desired body from the modeling window (or use
the Model Tree).
-
Click the Point
collector (under Origin) and select a point from the modeling window, or double click the
Point collector to open the Model Tree (from which the desired point can be selected).
-
Define Axis 1.
- Point - Select a point that lies on the desired
alignment axis for the joint.
- Vector - Global axes can be used for vectors by
clicking on the desired axis (x, y, or z) in the modeling window or by browsing through the Model Tree.
-
Define Axis 2 using the same steps.
If editing a compliant joint, see Edit Compliant Joints or Bushings. To edit user-defined
properties, see Edit User-Defined Joints.