A Line in the Sand
robdobson.com
robdobson.com
https://www.kickstarter.com/projects/1199521315/sisyphus-the...
Edit: might be quieter with more sand. Realize that was just a proof of concept video. Also not sure if the gears can be made to be quiet.
Cool mechanical engineering, could build 3D printers and what not.
[1] http://gizmodo.com/386879/sisyphus-v-a-robot-making-a-zen-ga...