Nurb path not rotating or moving in lower section of double pendulum I would like advice on best approach to simulate double pendulum as rigid bodies. I tried 3 UV Sphere connected by strings as nurb paths extending a youtube simple pendulum Blender example which I did get to work. I seem to have hit a dead end.
The .blend file is attached using Blend_exchange.

With this double pendulum, I can only get the middle ball to swing and, after adding the lower nurb path, the bottom ball just gets stuck locking the second pendulum although as you can see the ball's origin does get disembodied on a move - just not the ball itself which remains stuck.  As a newbie, I expect I'm missing something obvious and hope someone can help me out.
I managed to build the double pendulum.  The simulation shows the expected chaotic motion of the two pendulum bobs and so it looks like the Blender physics rigid body simulation is accurate.