Automatic Chicken Coop Door Closer

[reviewum]

Hey All,

It's been a while (years) since I've called on the collective genius of the members of this great forum, but I need some help.

I have 7 chickens that put themselves into the coop at night, but the dummies won't close / lock the door behind them (go figure). If the wife and I don't get home in time or forget to close the coop door then we've left a tasty snack for local raccoons.

So, I want to build a contraption that will close the coop door automatically at night. I know there are plethora of ways to accomplish this (photo resitors, geared motors, etc.) but I want to keep this as simple / fool proof as possible.

Here is my idea / design so far:

1. A vertical door (on rails?) that is lifted and latched manually (using a pin).
2. A simple timer (the $5.00 guys you get to turn lights on and off in the house) that is set to turn on at 7:00 pm and run for the smallest interval of time (say 3 minutes).
3. A solenoid, actuator, etc. that will be activated when the timer kicks on and pull the pin.
4. The door is released and gravity pulls it down to closed position.

So, where do I need help? Well, everything related to step 3, especially related to whether I use a solenoid or an actuator? I need something that:

1. Can run off a simple wall adaptor (Around 12 volts and 300 mA?)
2. Is strong enough to pull a pin under a little bit of load
3. Can be on for 3-5 minutes without burning up

So, any suggestions, pointers, advice to save our chickens?

Thanks in advance for your help.

 

[HEY HEY ITS HENDO]

Hi, welcome back!, you seem to have it pretty well sorted ...
so a pull solenoid should get you going ...
one here on ebay http://cgi.ebay.co.uk/2-Lucas-Ledex...ageNameZWD2VQQcmdZViewItem?_trksid=p1638.m122

i think similar ones are used for auto central locking systems
....you could maybe wire it through an additional switch so it also disconnects the supply voltage once its been activated....

 

[HEY HEY ITS HENDO]

oh yes and maybe a small counter weight attached to the door,up over a pulley,
will make th activation easier and prevent the vertical door slamming down like a guillotine

 

[reviewum]

Thanks for the reply. A quick question: What's the difference in a solenoid and an actuator?

 

[HEY HEY ITS HENDO]

Actuator.....a servomechanism that supplies and transmits a measured amount of energy for the operation of another mechanism or system

... so the timer is the actuator in your system

solenoid ....a coil of wire that acts as an electromagnet when electric current is passed through it, often used to control the motion of objects.

 

[65535]

They make linear actuators that will be able to both open and close the door slowly on a timer, just look for a 115v linear actuator and wire it up with limit switches and to a timer that will open and close it, a simple circuit would work.

 

[Lit Up]

The question I have through all this is how can you be assured the chickens are going to know it's time go in before the timer goes off?

 

[reviewum]

Good stuff guys, thanks.

A few items:

1) Chickens always go to bed (to their coop) at dusk. I just have to make sure the timer is set to go off after dusk. The wife and I don't usually remember to close the coop until a few hours after dark anyway, so having a timer that goes off within 30 - 60 minutes of when it gets dark will be better than what we do now. Yes, I understand I'll have to adjust the timer seasonally, but I'm fine with that.

2) I just got 2 car door lock actuators off of eBay. I was just really curious how these work and what they do so I got them ($10 after shipping... couldn't pass it up).

They seem to run fine off of my wall adapter that only supplies about 300 mA and is stronger than the 12 volt pull solenoid I had on hand (it required about 1.5 amps to pull).

Keep in mind I want to keep this as simple and inexpensive as possible. My next questions are:

1) Let's say I use a simple lamp timer, will having it power the actuator for 1-3 minues after it has reached it's end point burn out the motor inside?

2) Is there a REALLY simple way to either
A) cut power to the actuator once the door is released
B) only give the actuator enough juice to pull it in to release the door

Best case would be if I can power the actuator for a few mins. without causing too much perm. damage. Then all I need is a timer, wall adapter, and the actuator. Then all I need to do is build the mechanics to have a pin that is pulled and releases the door.

Thanks again for the help and suggestions!

 

[65535]

Simple idea. Get a limit switch for the bottom of the door mount it so that when the door is down the limit switch opens the circuit and cuts power going through it. Set a lamp timer that turns the system on after dusk the actuator will allow the door to fall closed (with counter weights so no decapitated chickens.) once the door is closed the limit switch will cut power to the actuator, this only takes seconds, set the timer to turn off 5 minutes after it turns on. You will have to manually open the door, so make a latching system that works like a car door or any door that closes and latches and opens when the bolt is removed (actuator is powered).

Hope that helps.


For the latching system you could mount a 2x4 onto the door, get a door lock (the non locking interior room type that you have on your non locking rooms) and make it so that the actuator pulls the bolt out and the door is free to fall, it should be reasonably simple to make.