Another plastic part in my house broke, so i decided to replace it...

This comes from a rolling hanger rack that I use, the diameters of mine are:
1 1/8in to the center & 1 1/8in to the bottom & 1in to the side

The fit from my printer was nice and tight so I recommend you use a nylon or rubber hammer to give it few good taps in order to install. I printed mine without supports.

*Edit: I added the end cap for the 1" side, you will still only need the hammer to install.