self-closing doors for chicken coops?

Permacltur at Permacltur at
Mon Oct 12 16:01:20 EDT 1998

In a message dated 10/12/98 10:24:27 AM, JRHALL at wrote:

<<Does anyone have information on how to open and close a chicken coop door
automatically, using a photo sensor or timer? <<

REPLY:  Yup, that one is right up there with the wood fired chain saw in the
Inventions that were never Invented Hall of Fame.  I taught permaculture at a
prison in Massachusetts for a number of years and we had some pretty brilliant
students int he class with not much to do.  Nobody solved the problem.
However maybe you did with the next question.

>>Also, I've wondered if any inventor or company has created a wind-up lazy
susan that is designed to approximately track the sun?<<

REPLY:  here we have more success.  Jaraslov Vanek, founder of STEVEN
foundation, has developed at least two self-tracking devices for parabolic
trough steam generators.  The first uses a fraction of water pumped by the
solar steam engine to run a water clock, in this case an inflated inner tube
that exactly fits inside a 55 gallon drum.  A round disc attached to a pole
rests on top of the inner tube.  As the water rises, the tube floats up
pushing the rod which is attached to cables and counterweights that drive the
reflector.  Vanek used an elevated 55 gal drum as a water reservoir, rather
than pumping directly, and repumps the water back at the end of the day.  This
avoids having the device fail during a cloudy spell whereupon it would have to
be manually reset before it works again.

The other I don't understand as well, but it involves coeffici9ent of
expansion and tubes filled with water.  It is much smaller and basically
depends on the trough to shade it.  If the sensor gets hit by direct sun, it
releases some water and the trough settles toward it a bit, getting back in
exact focus again. I assume the western edge of the trough is weighted somehow
to pull it in that direction, but I really don't remember.  You can get the
info from Vanek at 414 Triphammer Rd, Ithaca NY --zip escapes my mind--  Send
a reasonable contribution for his work--he works free all over the world where
poor people need his solar inventions and the money has to come from those of
us who can pay for the information or the poor people are screwed (yet

>>Lastly, has anyone in a winter climate experimented with creating a mini-ice
house, perhaps filled off an out building roof and allowed to freeze?<<

REPLY:  I have a standard design for that based on a design project I did for
a woman in Northern Ontario.  However it is pretty simple.  Use tapered Ice
cube trays and spray the sides with teflon so the ice slips upward as it
expands.  Make the cubes about as big as you are willing to handle.  Remember
a cubic foot of water is 7.4 gal and a gal weighs 8.3 pounds so you can get
into serious weight fairly quickly.  

However, if you have done a decent job of insulating the roof, or if it is an
unheated outbuilding, the snow should not melt until spring.  There are
periodic thaws in many places, howoever.  You can fill the first batch of
giant ice cubes off the fall rains and then make more ice as you get thaws or
whatever.  Make sure you attend to the insulation of the ice house.

For Mother Earth, Dan Hemenway, Yankee Permaculture Publications (since 1982),
Elfin Permaculture workshops, lectures, Permaculture Design Courses,
consulting and permaculture designs (since 1981), and annual correspondence
courses via email.  Copyright, 1998, Dan & Cynthia Hemenway, P.O. Box 52,
Sparr FL 32192 USA  Internships. YankeePerm at  

We don't have time to rush.

A list by topic of all Yankee Permaculture titles may be found at
Elfin Permaculture programs are listed at the Eastern Permaculture Teachers
assn home page:

>>Thanks for any ideas or feedback-
Jeff Hall, Ames Iowa USA

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