I was inspired by a Video uploaded by Chris Ramsay on the Impossible Nut & Bolt puzzle a level 10, Hanayama Puzzle. After watching the video I wanted ...to attempt to design and model this puzzle. I do not own this puzzle idea and this is just an attempt to recreate the model for it.
I found the nut was way to tight on the bold but still spun with a good amount of force so I added a looser nut version.
Edit: People were cheating and taking out the hidden object before finishing the puzzle. So I modified the inside to include a chamber that can only be accessed once the puzzle is completely opened.
EDIT 2: After some suggestions I have included easy removal versions of the screws to help prevent breaking the screw when removing from fixed build plates. If you are using a removable flexible build plate use the standard versions.