hinges one piece

I noticed that it was necessary to glue the 2 parts for the hinges of arm except that I didn't have strong enough glue (each time the piece would come off because of the pressure when I turned) .
I decided to modify the piece to be able to print it in one time, you just have to force a little to make the arm enter by the notch and it will not come off anymore.
Very useful and very resistant I advise you if we do not have glue or just that you want a strong part (think to modify the size if you want more or less movement) .
I leave you the file fusion 360 if you want to modify the notch to adapt it to your needs :)