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Atlatl dynamics

TitleAtlatl dynamics
Publication TypeJournal Article
Year of Publication1981
AuthorsBAUGH, R. A.
JournalLithic Technology
PublisherUniversity of Texas - Center for Archaeological Research
Place PublishedSan Antonio
Type of Articlearticle
Publication LanguageEnglish
ISSN Number0197-7261

J. Whittaker: Video digitizer and mathematical model used to predict velocity of darts under given conditions. - horizontal force, wrist torque, mass of hand, radius of gyration, weight of dart, length of atlatl. Simpler model than Cotterell and Kamminga 1989.
Hand-thrown dart has short lever action (hand+wrist) while atlatl is much longer lever.
Conclusions: Atlatl length (between .3-.75m) has little effect on velocity, although optimum length was .45 m. Adding a weight to atlatl can increase velocity up to 2.7%, but if atlatl at optimum length, always loses velocity. Heavy darts do better with short atlatls. Hand thrown dart (2 different weights) has 62-75% kinetic energy of same thrown by atlatl. Flexible atlatl transfers more energy to dart - their atlatl stored ca. 6.9% of dart's kinetic energy - more flex would be even better. Dart flex contributes little energy to forward motion, is mostly vibrational, but important in getting straight throw despite curving motion of atlatl. [Are differences of 3-7% real or random? I am dubious about effects of both atlatl weights and flex, but he’s right that dart flex adds little energy. I have trouble understanding his explanations of physics.]