When you cannot model a kinematic-chain on one Plane, it is a Spatial Kinematic-Chain.
A spatial kinematic-chain may have Cylindrical, Spherical and Helical-Joints. However, MechDesigner is limited to those kinematic-chains with Spherical-Joint. With Packaging, Textile and Automation machinery, the spherical-joint is used almost exclusively. In fact, I have used the Cylindrical-Joint only one time, and a Screw-Joint only one time.
In MechDesigner, we use the term 'Ball-Joint' for the 'Spherical-Joint'.
Ball-Joints and Mechanism Misalignment
In machines, two Rod-End Bearings at the ends of one Part are frequently used to allow a small amount of misalignment between two other parts in a kinematic-chain. When the primary function of the Ball-Joints is to make sure the mechanism does not bind, then model the mechanism on one Plane with Pin-Joints as a 'planar kinematic-chain'. But, of course, in your machine, use Rod-End bearings.
|•||We will look at 'Planar' and 'Spatial' mechanisms.|
|•||We will design a typical spatial mechanism.|
Spatial and Planar, Design a Spatial Mechanism