Wind reference indicator with hard rubber head fitted with ball bearing

摘要

The wind reference indicator is made of hard rubber and a ball bearing takes over the rotation, also the fixing results without a fixing screw. A hard rubber piece is machined. A 10 mm ball bearing is used. The hard rubber piece is drilled approximately 8 mm, and the ball bearing is pressed in the drilling. The wind reference weighs four gramme so that gentle breeze only would move this weight. The drilling in the head for a spring would be in accordance with the spring size. The greater size of spring chosen, the smaller the breeze required to move the wind indicator. The ball bearing has no revolutions, so that it does not require lubrication.