Not in official great ball contraption scale but great idea for it, the effect of balls descending across the several floors is very nice, also the use of vintage curved railroads.
MOC Lunar Module
Here I present a classic moc made of my own, in blue and yellow, made with only the parts of the sets 8040 and 8035. From years 1985 and 1986 respectively.
It has two functions:
-Steering
-Radar antenna rotation
And additional images
Lego Integraph : graphic planimeter by Nico71
An Integraph is an instrument used in mathematics for plotting the integral of a graphically defined function.http://en.wikipedia.org/wiki/Integraph