Bad CoonImproved, but still kinda tacky

Bad CoonBrand Goldberg Chicken Door Closer

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Door closer gif

This is the long awaited "better design" improvement over the infamous Kaczynski mousetrap model that people kept whining about. (ok, I had sore fingers too, but if you wanna raise chickens, you gotta be tough) As before, a bungie cord holds the clock in. Please note: your design doesn't have to look as tacky as mine unless you're intolerant of details. The frame I used is a wood 2x4 (but titanium will probably work as well), which can be mounted on the henhouse wall at the best angle to accommodate the layout, but some care should be taken so the trigger can fall free when the alarm rings. A slot is cut in a piece of plywood for one of the clock legs to orient the clock with the wire trigger, so the clock is easily removed to wind & set time. A couple of nails will keep it aligned just as well, if you rest a clock leg against one. The clock's alarm hammer directly contacts the trigger mechanism. Battery clocks probably have enough power to trip this design if the multiple triggers are arranged so the pressure on the alarm hammer is feather light. But there will be no one to turn the alarm off so the battery may run down without some kind of damping device (see below: 2 solutions). I got my clocks at RiteAid (wind-up or battery from China for around $10, American just like it for $39). Remove the clock bells.

Mount the shock absorber like the one shown in the drawing rather than the photo. Some free play is necessary for smooth operation, but the photo design allows the door to drop unrestrained for several inches as it begins to close, which could be enough to whack a hen. The drawn configuration is preferable to the photo because it gives a lower mechanical advantage to the free play (so the door doesn't drop at the beginning). The shock absorber should have several nuts locked together on the top end to prevent the friction of the rubber grommet from turning a single nut after several flex cycles. Said turning could loosen the bolt and alter the restraint on the 2x2 causing it to either freeze up or drop the door, either case resulting potentially in unspeakable carnage. (I bet the CIA is eating this up dudes, so don't carry one of these onto an airplane)

Too much dust in the hen house will work it's way inside the clock. Therefore; either sweep the floor, or when the timer is unused, store the clock in a plastic baggie. Another option is to take the clock apart & place dust gaskets around the knobs, winders, and hammer 'handle'. If you don't have felt, sweat shirt material works fine. Cut the gaskets about 1/2 inch larger radius than the hole in the case, sandwich the gaskets between the case & the clocks internal frame, but be sure it doesn't get caught in the works. Punch holes in the gaskets for the knobs and a slit for the hammer. Another AMAZING IMPROVEMENT in the Goldberg model is the inversion of the clock (it's upside down!) so dust won't be as likely to fall in through the hole for the alarm hammer, unless it falls upward. (That's why fly specks accumulate on the ceiling! Even as you read this, NASA is conducting experiments based on this phenomena, but they won't talk about it.)

An update on clocks: (1 Jan '07) I've replaced 4 of the $10 clocks made in China and sold through Rite-Aid, and I'm not too happy with them. They last about 1 year apiece before the alarm spring wears out. More expensive clocks are in the process of being appraised under the harsh test conditions afforded by our 3 hens, so be sure to check back next year for a full report.

Ok now it's next year (Dec 26 '07) Here are two solutions. The problem is probably the alarm spring wearing out due to getting run down completely every time it rings.

It's the gears, not the spring (July 27 '09) It still goofs up. Plastic gears in cheap clocks aren't designed to last more than a few years at most. Cheap material, the short term foul of competition comes home to roost from China. So just get a good clock, ok?

Here's another kind of clock (Aug 12 2011) 2 years later and this setup is still working fine though still a cheap chinese clock, so please notify the world that I limit my disparagement to only Equity and Advance brands with external bells.


To adjust the primary triggers' pressure against the alarm hammer, position the secondary trigger under the primary trigger, either closer or farther from the clock.
Trigger demo
Closer allows more pressure against the hammer, farther away = less pressure. With a further series of triggers this way, it's possible to hold a door weighing tons. Our coons are sometimes very bad, but they haven't yet got past a 5 lb door (A lot depends on the doors' fit though, so they can't get a tooth or finger around it). The right pressure on the trip mechanism is when the trigger rests snugly yet lightly against the hammer, somewhere between the following extremes: (1) falling off prematurely whenever a gnat sneezes, or (2) pressing so hard that the hammer can't move when the alarm goes off. Longer triggers allow a greater range of adjustability. When the right pressure is found, drive a finish nail into the wood 2x4 frame to mark the spot & use the nail as a rest for the secondary trigger.

The photo below shows the layering of plywood pieces (odd scraps) to frame and secure the timer. Nails will work as well as cut wood pieces.


Click thumbnails to enlarge

? <--- The Fusarium (clock removed) shows hole cutout for clock knobs & winders.

<--- Closeup of hammer & trigger, red material is gasket cloth.

Genuine testimonials:

Thanks Bill, I feel totally enlightened. I wish I had this device 10 years ago. After losing flock after flock of ducks and ducklings, and a couple of geese we got tired of raising prime food for the coons. Cheers.

A.F., Mendocino County 4-H

This is a rave on Bill's low-tech chicken door gizmo. Before, whenever we wanted to go out for the evening, we'd have to get a neighbor to come close the coop door. My favorite part is the shock absorber, which makes the door come down slowly, not slamming down on any poor hens. My least favorite part is the mouse trap, so Steve sets it, not me. Indeed, this invention has made life easier for us all.

Barbara Faulkner

Mission Statement
The primary objective to develop the Kaczynski "Bad Coon" Mark I concept design and hardware with direct scaleability is: directly scaleable weights, margins, loads, design, fabrication methods and testing approaches: traceability, technology, and general design similarity, to a full-scale Mark II (Goldberg) system. The "Bad Coon" is intended to demonstrate the technologies necessary to achieve systems integration within the mass fraction constraints of chicken coop door closeing devices. In addition, the "Bad Coon" will meet operational requirements outlined in the Mil-Spec CCDCD. Pg 244, sec 18, pp 7-16. The "Bad Coon" Mark II (Goldberg model) is envisioned to operate unpersoned. Fusarium is the genus name of a group of pathogenic fungi, and has nothing to do with design engineering or structural nomenclature even though it sounds like it should.