Although designed for use on the cupola described in Part I, this weather vane, Fig. 19, can be adapted for installation on almost any roof ridge. In such cases, a longer shaft would be needed, and another method of
supporting its lower end and the commutator. For installation on the cupola, a center crosspiece is toe-nailed to come flush with the top of the body section as shown in Figs. 14 and 15. In the photo a block is above the crosspiece, but it is better to attach it under the crosspieces as in Fig. 15, which will provide more space between the cupola roof and the commutator, particularly if the roof has little slope. A penciled cross made by using a straightedge diagonally across the body section to opposite corners, locates the point for drilling a three step counter-bored hole through the crosspiece and block. The top part of the hole seats a hearing. The center part should be a shade larger than the shaft to permit its easy rotation. The lower part of the hole is of a size to take a large head machine screw that projects below the block as an electrical contact. Fig. 16 shows the shaft, bearing and steel ball in the hole. Weight of the shaft on the ball assures a good electrical contact; end of the shaft is cut off 90 deg. and polished.
Source: Workbench Magazine July - August 1967