I had to sand the male threads on the piece with the ball (make them slightly smaller in diameter.). Otherwise, no problems with any other threads. I think the support material has something to do with it. I printed that piece with the thread side down.
It was my first time designing something with threads. Theoretically tinkercad should have made that pretty easy, but they were definitely a few fitment issues. The only real issues I had with it was the ball joint snapping if there was too much tension on it when trying to adjust. I did add some space in the ball droids to be able to run an M3 bolt through to provide some rigidity.
I had quite a bit of trouble with threads being too tight when i first started. This video helped (accent is a little strong). I also had the same problem with ball studs breaking off. i just made the neck bigger.
