Here is my mobile. Perfect for the DIY parent. I will be posting photos of this in action soon. My wife is making flowers out of fabric to hang out this.
This could be printed in PLA, but I would recommend PETG.
I would also put a drop of glue on it, to hold it permanently together.
If you make this, please post a pic! I think it is really neat to have people making my designs.
I would add some extra walls for strength, and maybe bump up the temperature 5 to 10 degrees. Make sure the parts are oriented properly, as that has a large effect on the strength of the parts.
Enjoy!