Derek Hugger wrote in to say that he has spent the past few months designing a fully mechanical marble machine. Titled Kinestrata, the assembly is driven by a 2 1/2 pound weight via the classic Graham Escapement -- named for George Graham (1673-1751)an English clockmaker and inventor who is thought to have created it around 1715.
Kinestrata measures 11 x 17 x 5 inches and contains some 386 parts. The balls roll down 4 unique tracks and are lifted back to the top of the machine by 3 geared lifter rings. Hugger says that it took roughly 400 hours to design and build! Plans should be available for it in the next month or two. We'll keep you posted!