The assemblies can be either rigid or articulated, they are then called mechanisms.

Mechanisms (e.g. : Cylinder, Rolling, ...) have internal degrees of freedom that allow them to be included in a higher level assembly in order to satisfy defined positioning constraints.

This way, it will be possible to utilize the stem in the casing of the jack to fit it in the assembly being used.

Regardless of the method used to create the assembly, a rigid assembly is ultimately achieved, which can then easily be transformed into a mechanism, if necessary, in a designated later stage, the modeling stage (i.e. once the parts of the assembly have been defined and finalized): the Mechanism Stage.

This also applies for an assembly achieved by importing a neutral STEP type format or similar, which only contains the information enabling the parts to be positioned correctly, but not which defines if they are mobile or not, and if the case, how.

This option is a considerable benefit compared to other products which only provide the notion of constrained positioning, and which therefore do not allow a part designed on site to easily be made mobile, or whose positioning constraints have no relation to how it is supposed to move.

Most of the commands to use to define and manipulate a mechanism are located in the Mechanism menu and it will also be very useful to use the contents of the Mechanism folder in the entities tree, which will contain all the relevant information on the composition of the mechanism being defined.

Rigid Assembly

You can create assemblies that are not mechanisms (this mode is used when creating a new assembly with a blank template).

These assemblies do not have the Mechanism folder in the entity tree, nor do they have the Mechanism stage. They correspond to composite parts or rigid assemblies, such as, for example, fabricated chassis.

It is possible to change this kind of assembly to a Mechanism with Mechanism ... command of Mechanism Menu. The same command allows you to perform the reverse operation if a mechanism assembly is applied (like a mode).