Mike,
Well, a true arc is what I’m after, for the front bulkhead and everything that rides with it, the swingmass included. Actually I feel the opposite for the nesting. As the artbox arms, the aft bulkhead, the diagonal brace etc are attached to the vehicle, they don’t move. The upper and lower ArtBoxArms rotate up and down about the aft pins, and everything pinned at the forward end of those arms (frontbulkhead, then swingmass (potentially) nested within it) moves up and down on the arc that those holes follow. The following idea, I feel, MIGHT make that arc just happen naturally, if I could figure out how to execute it: I’ve tried nesting a set of pins (in the lower holes or the upper, it wouldn’t matter), then nesting the swingmass in the pins. Then, as the artbox arms rotate up/down, the nested forward pins and in turn the nested frontbulkhead and then the swingmass would all rotate in that arc, to which I was going to counter the rotation with equal and opposite RotX values, applied where appropriate. But when I nested the swingmass into a pin, it all inflated to about 5 times the size it should be and distorted to some crazy geometry that made me thankful there’s an UNDO button. If I could somehow lock the scale of all that, would it prevent that from happening? I’m just into dynamic components recently and am surprised that in just a short time I’ve been able to do what you see in the model. The lock scale feature however is something I’ve only read about others doing, not having need for it myself. So I wasn’t paying much attention to it. Apparently I should look into it further. Would that even work?