Corner Balljoint

This is a corner bracket to perform a threeway connection using ball joints to build a catnet on my balcony. It connects two horizontal aluminium rods (12mm outer diameter) with a vertical steel pipe (17mm inner diameter). I used a more fixed solution in the past, but during windy conditions or a bird sitting on a crossbeam it always broke. This is the next attempt in doing a more flexible connection. So far its holding now for 4 month now, even so i broke one part during assembly.