In a very similar vein, have you seen the amazing wood machines from http://woodgears.ca/ http://woodgears.ca/ ? He has a binary adder: http://woodgears.ca/mar

In a very similar vein, have you seen the amazing wood machines from http://woodgears.ca/ http://woodgears.ca/ ? He has a binary adder: http://woodgears.ca/marbleadd/index.html http://woodgears.ca/marbleadd/index.html