I took what was done by BManx2000 (https://www.thingiverse.com/thing:2541970) and modified it so that it was it's own freestanding unit. The ball and socket is just copied directly over from his thing (https://www.thingiverse.com/thing:2539262). I printed everything in PLA with good results. I did have a couple sockets split during assembly. I tiny bit of lubrication helps with assembly (none of the lubed sockets split).

Print the post with supports everywhere so that the balls are supported from the base plate during printing. You will need to sand the balls where the supports were touching to make a smooth surface for easy assembly and good function.

I included the step file so that you can modify it to suit your needs.