Rotary ball as air current detector

摘要

A hole of roughly 3 millimetres diameter is bored into the top of a threaded bar (1). The spherical segments (3) are cut out to an exact pattern and cylindrically rolled. The rotary speed can be regulated by the distance between segments. Alternatively, rotors of any type can be placed on the top by means of a threaded attachment (5). The spherical segments can be fixed in a suitable position by tightening the nuts (6).