Homestead mailing list

["WILLIAM JONES" <billj AT harborside.com>]

Wendy wrote:
>I'm not convinced that this contraption will be useful, but here is an idea 
>to hold the bottles together:  take some of those big ty-wraps and fasten 
>them >around the bottle bundle (or you could ty each bottle individually).  
>For added rigidness, use two-part plastic epoxy to glue the ty-wraps to the 
>bottles >after fastening.   BTW look for the type of ty-wraps that has the 
>plastic fastener.  Those with the metal fastener might rust out in the water.
Well, bear in mind that the diagram just minimally illustrates the concept.  
Six floats are about half as many as you would actually need, since the 
torque profile would be extremely lumpy with only six.  In other words, the 
more floats, the smoother the action.  To inplement more than 12 bottles, 
it's probably better to start pooling the air from several bottles that send 
air to the same float.  Because the air pressure involved is so low, mere 
wine corks and drinking straws can be used as connectors. with sealing wax or 
tallow.  But even one bottle is capable of generating about a pound of 
buoyant force, since the air expands by about 10%, or one cup.  When I first 
made the bottle you see in the picture, I used a glass swizzle stick to 
weight it down in a glass of water.  It's a good thing my eye wasn't right 
above it when I laid the bottle in the sun, because the swizzle stick leapt 
right out of there and broke on the concrete.  And BTW, don't leave the 
bottle sit in the sun indefinitely.  It WILL melt.
Now's a good time for some background info.  I first dreamt of a buoyancy 
engine when I took my basketball into the pool when I was about 8 or 9.  I 
let it go and it smacked me real good, right in the nose.  I thought, this 
has got to be good for something.
If you think about it, there's a buoyancy engine in every pet shop.  It's 
called a bubble wheel.  I guess you could that an "open float" buoyancy 
engine.  Mine is a "closed float" buoyancy engine, mainly because the change 
in air volume is so small that we have to hoard every bit of air.
My ultimate goal goes way beyong water pumping.  I would like to power a 
humble conveyance, like a bike powered by compressed air, with enough 
capacity to make it back and forth from the market.  I call it the Wirtz 
bike, after the fellow who did so much work on these devices over 100 years 
ago.  I would like to use hydro power, wood, or solar to pwoer it, each 
according to its season.  Unfortunately our little creek is completely 
shaded, so the only model we'll be showcasing at the Museum of Fluid Power 
will be a toy that works in a pond filled by the creek's hydro power, perhaps 
a 24-bottle model driving an elaborate fountain.  But the neighbors have a 
big pond that's in full sun, so who knows.
Bill