This puzzle was dropped off on my desk last week. The "rocket" is placed in the cup. You must remove it without dumping it out or using tools (paper clips, tape, etc.). The problem is that there is no place to grab the rocket. How do you get it out? See video at the end if you can't figure it out.
I usually make projects from wood but I don't have a lathe. Therefore, I opted for a 3D print with dimensions taken from the wood version. The CAD files are included.
The wood version can be purchase here: http://amzn.to/2hV9NL0
More Info: https://www.instructables.com/id/Newtons-Gravity-Defying-Puzzle-3D-Print/
Solution Video: https://youtu.be/fVAllOlHQvs