You have constrained the components of your assembly, but you have left some degrees of freedom to be used in the Dynamic Simulation environment.
By the way, converting the constraints to joints, you get the warning that the mechanism is over-constrained for the simulation.
Let’s try to explain this behavior with the simple data set you can download from here.
- Open the assembly 4_Bar_Linkage.iam
- Un-suppress the constraint Insert:4
As you can see, at this point you can drag one of the ungrounded components to verify the correct kinematic of the assembly.
By the way, if we take a closer look to the assembly we can see that, by virtue of the face-on-face types of constraints, the 3rd link face is already co-planar with the Base face.
As you know the insert will do both an axial align and planar mate, but the planar mate is not needed.
So, we can conclude that in assemblies we allow the constraints to be “over-constrained but consistent”.
At this point we go in the Dynamic Simulation environment.
For demo purposes we have disabled the option “Automatically Convert Constraints to Standard Joints” in the Simulation Settings.
- Click on the Convert Constraint command
- Select Link:2 and the Base
- Click OK for creating the Revolution joint and get the warning that the mechanism is over-constrained
It is the same sort of thing you learn in Statics engineering course, where a system can be statically indeterminate.
That is, there are more unknowns than equations, so there is no unique solution.
So, in order to avoid the indetermination you have two options.
The first one is applicable when the option “Automatically Convert Constraints to Standard Joints” and consists in clicking on the command Mechanism Status.
By the way, with more complex assemblies, the Mechanism Status and Redundancies dialog, in some cases, cannot provide the alternative Joint that solves the issue.
In such cases, it is necessary to edit the assembly constraints and avoid the “over-constrained but consistent” situation allowed in the assembly, but that generates the warning in the Dynamic Simulation environment.
So, in this case, the second option is the following.
- Delete the Revolution Joint
- Exit the Dynamic Simulation environment
- Replace the Insert:4 constrain with, for instance, a Mate constraint between the axis and the center point of the circular edges of the components Link:2 and Base