Tutorial 12: Spatial Mechanisms

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Tutorial 12: Spatial Mechanisms

Spatial Kinematic-Chains and Ball-Joints.

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.


IMPORTANT:

Ball-Joints and Mechanism Misalignment

In machines, Rod-End Bearings at each end of one Part are frequently used to allow a small amount of misalignment between two 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.


This Tutorial

We will look at 'Planar' and 'Spatial' mechanisms.

We will design a typical spatial mechanism.

Icon-AddBallJoint Spatial and Planar, Design a Spatial Mechanism

Step 12.1: Is my kinematic-chain 'Planar' or 'Spatial'?

Step 12.2: Design a typical spatial mechanism