The Russian Felix M calculator

The Felix M is a pinwheel calculator made in Russia from 1929 till 1978 with virtually no change in its design. It is closely modelled on the pinwheel calculator made by Odhner in St. Petersburg before the Russian revolution, because Odhner's machinery was confiscated and used to set up production of the Felix. Millions of these calculators were made. Errata: The first Felix was probably made in 1929, not 1928, and my Felix-M was probably made in 1976, not 1975. For more information about this and other calculators in my collection, please visit my website: https://www.jaapsch.net/mechcalc/ 0:00 Introduction 0:44 The design, addition 1:05 Clearing registers 1:57 Counter, subtraction 2:42 Input clearing 3:11 Reversing direction 4:10 History 5:28 Felix Dzerzhinsky 8:08 Outro