Gravity-Powered Dog Door

Gravity-Powered Dog Door AG WORLD 27-5-24 Dan Fink, Masonville, Colo., wanted a dog door that would let his new puppy go in and out except when he was driving out of the yard in the morning. He knew that if the puppy saw him leave, she would follow. "I had to find a way to lock the dog up for a few minutes while I leave," he says. "I first built an electric timer and solenoid latch on the dog door, but she learned to hit it with her nose and get out." A neighbor suggested trying gravity power so Fink started experimenting. The front door already had a hinged flap dog door on the outside. Fink rigged up a solid sliding door on the inside, tying it to a water bottle. A rope runs from the top of the plywood door, through a pulley, and down to the bottle. A small plastic bucket that holds a quart of water sits on a nearby bookshelf. A plastic tube is tied to it so the end is submerged at the bottom of the bucket. Before leaving in the morning, Fink sucks on the tube to begin siphoning water and puts the end in the water bottle. When the bottle fills up, gravity pulls it down, opening the door. Adjustable hose clamps on the tube allow him to adjust the length of time it takes to fill the bottle, from 2 to 30 minutes. "It's never failed, not even once," he says, noting that it is much more reliable than the computers he works with daily. "Gravity won't let you down." Contact: FARM SHOW Followup, Dan Fink, Box 292, Masonville, Colo. 80541 (ph 970 227-5395; email: danf@ otherpower.com).

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