Bruce Shapiro is my new robotics hero: he built this awesome sand machine called a stratograph, where he used sand to amazingly detailed paint images
And another machine called Sisyphus III to "plot" intricate patterns in sand using a steel ball and a software-controlled tilt table:
Check out Bruce's website: The Art of Motion Control
NEATOSHOP'S BLACK FRIDAY SALE
Save up to 25% off ALL T-shirts from the NeatoShop! Hurry - sale ends Nov 29, 2015.