Posted by Dave Brown on November 05, 19100 at 20:00:53:

In Reply to: Re: Weathervane making posted by Jesse Wagner on November 03, 19100 at 07:43:34:

Jesse,

With regard to your question on "...how does the arrow supposed to be mounted so there is a desent bearing surface so the wind will turn the thing?" the answer lies in two places.

First is balance. Ideally a weathervane should be balanced at the pivot point. That is, there shoud be an even distribution of the weight to the front (arrow point) and the back (sail). This is to help minimize resistance to turning as the wind changes direction. A weathervane that is either front loaded or back loaded will not turn as readily and freely as one that is balanced.

Second, is sail area. "Sail area" is the surface area against which the wind will have it's greatest effect. The sail is that portion of the vane that is on the opposite side of the pivot point from the arrow point. It is necessary to have a larger surface area behind the pivot than in front of the pivot. When looking at historic weathervanes, the "banner" style vanes are probably the best example of "sail area" vs "balance". It is this "sail" that causes the arrow point of the vane to always face into the wind. Keep in mind that a weathervane is supposed to point to the direction that the weather (wind) is coming from, not the direction that it is going to.

As for your question regarding "cups", I'm not sure what you are asking here.

Hope what little I have to offer helps.

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