One of the aim I had in mind from the beginning of the project, was for the exo to be able to stand on its own in a static position.

This is not a must in general for exoskeletons, particularly passive ones, but I consider it a "nice to have" since any unbalance of the exo on its own, would need to be compensated by the user. The fact that this type of exoskeletons is mostly lightweight makes this not a big deal, however, as a personal challenge, I tried to achieve this, at least in a static position, since dynamically would be impossible for a passive system.

Having an exoskeleton standing on its own would mean that the center of gravity of the frame is located properly and that all forcing elements are preloaded correctly therefore trying to bring the user to that static equilibrium position.

Here is a first test I made with the whole body (arms still missing) achieving a good result since the exoskeleton already stands on it's own placing the feet correctly. It is still not a stable solution since the hip torsion springs are still missing (this would give stability to the position) but in this way some features of the design can be highlighted.

For example the fact that the legs can rotate around z independently from each other (notice the left leg way more rotated than the right one). Or for example the fact that the core gas springs compensate the weight of the shoulders/arms which otherwise would cause the exoskeleton to learn forward creating a torque around the spine pivots.

Following preview video of the exo standing will clarify all the described aspects.