Calculating the torque on the shafts of the Antikythera Mechanism to determine the location of the driving gear

Abstract

The Antikythera Mechanism (AM) is considered by the scientific community to be the first computer ever built. Its operation is not entirely known, derived only by the existing fragments of the mechanism that have been found and studied. From the early comprehensive study of the mechanism by Derek De Solla Price to the Antikythera Mechanism Research Project (AMRP), which performed the CT scans of the AM, the input of the mechanism was assumed to be a crown gear that was found on one of the fragments. However, all attempts to construct an exact copy of the mechanism found out that considerable torque should be applied to the presumed drive crown, in ordered to operate the mechanism. This paper tries to compute the transmission of torque from any of the mechanism’s gears to the rest of the gear-trains, to determine the best possible location of a driving gear or crown as the case may be. The computation takes into account an estimated rotation friction on each shaft that will result in further reducing the transmitted torque in the case of long gear-trains.