AxiomUltra said:
Good question! I decided not to keep the inner and outer shoulder separate. For one, it wasn't practical to keep them as sliding/overlapping pieces.
In the game the inner and outer shoulder don't have a lot of conflicting movements unless Shepard is holding onto something above his head - in which the geometry actually collides with his neck/head. So I decided that it wasn't worth trying to be "authentic" in that regard since his range of motion wasn't realistic to begin with. I also wanted the outer shoulder to maintain the proper distance from the inner shoulder. In the game the outer shoulder is actually hovering.
So after I decided to keep them attached, I measured the empty space between the two parts (approx. 1.25 inch gap) I then modeled a simple cube to fit in the space and trimmed it to fit flush on the surfaces.
After that it was just a matter of exporting the pattern out, locate the exact position for the cube with calipers, sketch where the piece would go, create a foam block at the right thickness, and epoxy the three parts together.
There are a few steps that are probably overkill to some builders out there who would just eyeball it. But since I had such a good resource I didn't mind getting the detailed measurements. (I also used the model to map out how thick the stripes were on the right arm parts) In the end I think that taking the time out to do those little things actually helped keep symmetry across the build.
The shoulder is connected with parachute clips (1.5 in nylon straps & clips) and connected just outside of the neck. Two vertical straps run over the shoulders for accuracy and help hold the first set of straps down. A thinner (1 in) nylon strap loop was put on to run under the arms since the game model also had it. This 1 inch loop wasn't made to be adjustable or tight, just to keep the shoulder from flopping all over the place.