The orignal Lego marble machine
It all started Christmas 1996, when my brother Markus pulled out the big box of Legos at home, and we started building various little machines again. Markus posed the problem of building a 'marble pump', which would elevate marbles by adding marbles to the bottom of a column of marbles, and push them up.
This was a cool problem, and we both immediately set out to develop such a machine out of Legos. I built one that was exceedingly simple but didn't run very smoothly, and Markus built one that ran very elegantly, but required five 40-tooth gears, and various connecting rods and sliders. The machine was cool to watch with all its moving parts, but not practical.
Early marble pump designs
The image above shows the first two marble machine pump prototypes. The machine on the left was my design. It basically had a cog that would raise the stack, and rely on another marble to roll down underneath the stack, then drop the stack onto the new marble. The big gear is the drive crank. It worked, but was very jerky.
The machine on the right is my brother Markus's design. Much more complicated - note all the gears. It was very tweaky, but when it worked, it ran very smoothly and quietly. The way it pumped marbles was just like subsequent marble pumps we built, but it was activated by two separate crankshafts, one for the slider motion, and one for the pistion motion.