Me: "What should we make now?"
My 8yo son: "Fidget spinner... nunchucks!"
My son then got sad and said it was a stupid idea and wouldn't work.
I told him it wasn't a bad idea, we were just brainstorming and we would try to figure it out. It took us while but we came up with a design. He loves this thing.

Basically every single piece spins/rotates. You can mix and match the pieces. I am including spiral, grid, and knurled.

Printing/Supports
-You can separate the objects and have less supports, you just have to put more pieces together (it is pretty easy). Inside the two bodies has a support, this must be removed before adding the end cap.

PLA Silk
-The end cap connector prongs cannot be PLA silk, silk is too rigid and they will snap (at least in all my tests). I made the end caps two objects (endA and endB), so you can make the visible part silk (endB), and make the delicate connectors non-silk (endA). The central ball joint connector can be silk. I would print the end caps separate from the body if you are doing silk (to reduce waste).

Multiple connector
-Be careful cleaning the supports, you will need fine needle-nose pliers most likely. You also need to make sure everything is cleaned of support pieces really well, otherwise it may not fully connect. It is a bit of a pain... but my son wanted to be able to have a "mega nunchuck" so I am including it. 

Spiral/Zig-Zag

If you want to make a zig-zag (see the green/blue silk in my photo) open the Spiral version, select “Split to parts”, then right click on the object and select mirror and choose x axis (do that for one nunchuck body and one end cap).