4 Bar and Virtual 4 Bar Linkage

4 bar linkages are very commonly used in FRC to create mechanisms that are able to move from a "closed" position to an "open" position. Four bar linkages can be an alternative to traditional pivots, but come with their set of pros/cons. Virtual 4 bar linkages are different from traditional 4 bar linkages, but have the same behavior, hence the name. Virtual 4 bars use a tension member, such as a chain/belt in order to recreate the 4 bar behavior. Videos below will discuss what 4 bars are, how to design with them, and a 3D model of a 4 bar and a virtual 4 bar.

Videos to be added in the future.