Making woodworking objects that move on their own is a bit foreign to many of us woodworkers. This makes these kinds of projects a bit more challenging ... in a fun sort of way. Trying to figure out how something works, and when you are building it, wondering if it really will work like it's supposed to.
There is a bit of a fascination with these little whimsical little ornaments, and if you happen to have an old antique one, you cold be looking at a very expensive artifact, or at least that what the good folks on the Antiques Roadshow have shown. The older, the more weathered and with almost no paint left these garden and shed ornaments are highly coveted.
Making whirligigs is fun and a bit demanding but there are a few things to keep in mind as you go along. The first thing to remember, even before you start, is with whirligigs, BIGGER is better. Remember, these things are often going to be at some distance ... in the garden, on the garage, shed or greenhouse, maybe on a far corner of the yard. All this means if you make it too small, it will be harder to see or won't even get noticed so when you think you have the correct size .... double it, make it really big so it can easily be seen and enjoyed.
Another important consideration is the wood ...
I see many of these made from plywood, which, unless it is marine plywood, is often not the best out-door material of you want it to last. Between the glues that hold the veneers together, the sun, the rain, burning hot sun and sub-freezing plywood can take a beating and not fair well. Cedars are good choices for 2 reasons, they are lighter weight (which means they will move around in the wind a bit better) and Cedar is a great out-door wood, and last quite well. the only down side of Cedar is that if doesn't hole paint that well because of all the oils contained in the wood (the same oils that make it such a great out door wood). Other woods can also work fine and for these I prefer the soft wood varieties, only because they are lighter in weight and are a bit more active ornaments.
There are many, many, many different designs and ideas, and if you are short on ideas, check out the Internet or Pinterest and you will be amazed at what it out there. There are simple designs and quite complex ones, the choice and challenge are yours.
In most cases the design of a whirligig is to catch the wind in such a way that a propeller on it will catch the wind and spin, which in turn, in some cases will animate parts of the whirligig or, just having the propeller turn might be the action. Most whirligigs also need to act as a bit of a weather vane in order to get the propeller in the right direction to catch the wind and spin as it should.
To do this, there needs to be a large flat vertical surface similar to a large upright vertical stabilizer on the back of an airplane. This large flat surface is what catches the wind such as in a large weather vane, then points in the direction the wind is coming from. The size of this wing will vary and will depend on how big the rest of the whirligig is and how well it rotates. You may need to experiment with this.
And speaking of rotating, the finished whirligig will want to be easily moveable on it's pivot point. There are many different ways of accomplishing this, including using a ball bearing between a couple of hard surfaces to allow it to spin easily.
Copyright - Colin Knecht