Kinetic sand mold that creates a marble mountain.

Here's a vid of it in action:

If you found this useful, it would bring me great joy to see your work - so be sure to share. :)

Or, just buy me a coffee: 

https://www.buymeacoffee.com/Julius3E8

OR… better yet, please feel free to dump a bitcoin or two here:

1Py3TUeR8noBN2giHyFV1GfB6x3Kh2WEVv

... include a note to the effect of "Hi Julius3E8, thanks for the [insert name of thing]... my life has improved five-fold on account of it and please accept this paltry amount in gratitude".

You're welcome! (in advance) :D

Also, feel free to peruse my other submissions which are almost as varied as they are many:

https://www.printables.com/social/320993-julius3e8/models

http://www.thingiverse.com/Julius3E8/designs

Enjoy!