Elbow joint (snap in, STL and 123d file)

hey.
I made this elbow joint in order to integrate it in other pieces, like figurines or some other parts.

It's two 10mm cylinders that are joined by a 90 degree (with one side flat on the male part) or 180 degree joint. Good for elbows and knees for the 90 degree version and for who knows what for the 180 degrees one (the one where the male part is completely rounded).

here is a short vid of the 180 joint: https://youtu.be/VCa5kigsRd0
It looks like it didn't go all the way to 180 bu