ABSTRACT
D. Cello MUBOT The cello M U B O T has basically the same system as the viol in M U B O T . How ever, a cello is heavier than a viol in , such that the mechanism o f the cello M U B O T is concretely different than that o f the viol in M U B O T . Similar to the viol in M U B O T mentioned above, the bow operating mechanism requires three move ments: selection o f an active string, pressure o f bow against a string and recipro cation o f abow. The reciprocation o f the bow is a simple mechanism, as shown in Figure 27. The whole mechanism moves on the arc-shaped rail to a position at which a desired string can be touched as shown in Figure 28. In contrast to a vio l in, the body o f a cello does not move. The pressure o f the bow is applied by pressing the wooden portion o f the bow in the vicinity o f the point o f contact o f the bow and the string. The fingering mechanism consists o f the pencil-shaped air cylinders as in the case o f v io l in M U B O T . They are arranged in a 6 x 6 array at the interval o f a half tone, totaling 24. The holder o f the fingers is capable o f moving along the direction o f the strings. The effect o f vibrato is enabled by recip rocating the holder wi th the motor and eccentric cam. Figure 12.29 shows the overall view o f the cello M U B O T .
