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In this Instructable I'll be showing how to make an easy automatic chicken coop door opener.

For anyone who keeps chickens, the ever present threat of predator animals like foxes is always a worry. We recently had all of our chickens (4 of them) killed by a fox and as you could imagine it wasn't a pretty sight. Usually when something like this happens its due to human error, like leaving the coop open. I wanted to ensure that this didn't happen again and so started investigating automatic coop doors. There are quite a few on the web, many expensive or just plain complicated. After much searching I finally stumbled across one which seemed like pure genius.

The door is lifted and closed by an electric car antenna which is activated by a timer. Simplicity itself! Electric antenna's are easily available from any car wreckers for next to nothing, and it's a great way to re-use something that just going to be land-fill anyhow!

There are a few versions on the net on how to make this door opener. I noticed though that they all used a couple of computer charges to power the antenna which made it complicated. My version uses a timer and battery and keeps everything simple.

The reason why I have included the word "simple" in the title is this really is an easy build. If you do a quick search on the net you'll see a bunch of builds which either cost a heap or seem really complicated. This project can be done for as little as $20 if you use mains power.

The following Instructable will take you through how to wire-up the timer and antenna and also how to mount to the door.

Your chickens ill thank you!

I've also included a short video of the door in action.(if you are using a mobile, try this link)


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DavidP195 days ago

After 6 months, I finally collected all the components to make this project. The final piece was the automatic antenna, which I picked up today at a salvage yard.

When I got home & connected the antenna to the battery to test it, only the first segment of the mast would extend and retract. If I disconnect and reconnect the battery, I can hear what sounds like a relay clicking on the antenna.

I tried carefully pulling the mast out by hand, and again, the first section extends easily, but the second section will only extend a few inches and I can't pull it out any further without risking destroying the gears.

When I hooked it back up to the battery to retract, it would still only retract that first section & left the second section extended a few inches.

I don't know if it makes a difference, but the battery is a sealed 12v lead-acid battery like the kind they use in kids ride-on toys.

Maybe the battery doesn't have enough amps? Maybe the antenna spent too much time in the salvage yard? (Although it looks almost new.)

Any suggestions would be greatly appreciated.

UPDATE: I checked the antenna with a new car battery, and the result was the same - it extends about 8 inches and then stops, with the relay clicking. I'm guessing the mast is gunked up from lack of use, or it's just not good any more.

lonesoulsurfer (author)  DavidP193 days ago

Must be your antenna. I could use a 9v battery to make mine go up and down (albeit slowly!)

darren13131 month ago
Whitesnake3 months ago
I've had no success with the timer, I'm on my fourth, the switching is either freezing the circuitry or the relay, even with spark suppressor and diodes I've soldered inside.

Any ideas?
lonesoulsurfer (author)  Whitesnake3 months ago

man - sorry to hear. Are you using the same timer as me?

Is the battery 12V? I don't believe it matters how many amps it is (I have used a 40a and 7.5a and they both work)

Have you tried to just use a battery and antenna without the timer? Does it work like that? The antenna should go up and down fine when it is wired up correctly to the battery.

The only thing I can think of is it might be the antenna if you are using a 12v battery.

Let me know how you go with just the battery and antenna.

That works fine without the timer, I have the connections in a temporary terminal box and have to connect the wires manually until I sort the problem, it's a shame really as when it works it's great, I just think when switching the surge is doing something (my antenna is slightly different to yours in the picture but still low Amps etc) initially it was the timers internal relay blowing so I started soldering new relays inside, but the something else within the timer is now shorting and draining the battery. The relays are fine and the timer digital board works fine, it just isn't switching the load with the manual button. (It's the same timer as yours).

I now have 3 timers, maybe I can make a good one, then I will add an additional separate relay and only use the timer to switch the coil of the additional relay, that way I'm only switching the load. Unless you have more ideas, I'm ok with relay logic and wiring but when it comes to the tiny components it's beyond me. (I recon Cnc machines so have some idea ;) ).

I did have a few problems with the chickens when they were chicks, they didn't perch and used to settle in the doorway, I had to add some safety features as big Betty got her head stuck in the closing door, (don't worry it was only for a few minutes as we used to watch them in ever night.) I installed an additional relay, the switch side reversed the motor and the coil was energised by an external 12v alarm PIR, works great, it's only activated when the door is closed, also added an led so I can see from the house if the doors closed at night.

Thanks for your reply mate, much appreciated. Shame I can't seem to add photos on the iPad.
lonesoulsurfer (author)  Whitesnake2 months ago

Hey there,

Did you manage to get your timer to work?

yes thanks I got it done in the end. I used a dusk till dawn photo cell with an average n delay timer to I can delay the closing. Works fine.

Had to put a larger solar panel on, the 10w didn't keep the battery topped up in these now shorter winter days.

correction..... An ON DELAY TIMER.

lonesoulsurfer (author)  Whitesnake2 months ago

Hey there,

Did you manage to get your timer to work?

lonesoulsurfer (author)  Whitesnake3 months ago

What a pain in the arse! The only other thing that I can suggest is to try a different timer. I didn't have any issues with mine (still going strong), maybe it is a faulty batch that the supplier is sending?

Poor Betty :) I hopefully shouldn't have any problems with the door closing on one of the girls. it doesn't go down until its dark and by then their roosting in their nest box. If one of them did get caught though it wouldn't last too long; the door has some force behind it.

Yeah it's a definite pain in the arse! Luckily Betty is fine, it actually stops and it's not so powerful, the only problem is you cannot push it back so easily.

All the purchases of timers were all from different suppliers, most of them put cheep relays inside and wasn't rated 16amps, I also used diodes eventually which saved the relays from freezing. The problem lies I think with it all being on a shared negative / load carrying earth sorta speak, and blowing components further up the chain.

I've gone for the option of putting in an independent relay again like the PIR has. By operating the coil side of the relay from a dusk to dawn photo cell, hopefully this should work.

At present the birds don't get out of their run/coop so if Mr fox is here on those bright 4am summer days they are still safe in their run. Hence the use of the timer. However. I do have a free replacement on the way, maybe I'll try operating another independent relay from the timer, keeping the complete timer setup away from switching any kind of load and only activating the coil.

Thanks for the replies.
klennquist2 months ago
How heavy can the antenna lift? What size and thickness did your door measure? Have all the parts now except that i plan for using 230v through an led driver tranformer... thanks for your inspiring creativity!
lonesoulsurfer (author)  klennquist2 months ago

Hey there,

The antenna's are geared so they should be able to lift a substantial weight. To ensure that the gears last though I would use as light possible material for the door. I used some ply wood, but a sheet of aluminium or thin steel would also be ok.

Good luck.

pitajames2 months ago


I have a new question about this project. I now have all the material required for realizing the project. However, I have a doubt. If I cut the antenna, there is a nylon cord inside. I don't know how to fasten the nylon cord to the antenna tube. Could you help me? Just another question: how long this kind of antenna usually work fine? Thanks again.

lonesoulsurfer (author)  lucio.narducci2 months ago


If you cut the very top of the antenna you should be ok. I don't believe that the cord is joined to the top (it wasn't in mine) I would go cutting any lower though. The good thing is, if the antenna is too long, then it shouldn't matter. When the door closes the motor inside the antenna will go through a few revolutions and then stop. It shouldn't damage anything (this is what mine does and its fine). the antenna doesn't have to fully extend to work, you could just have the antenna extending to half the length and it will still be ok.

Hope this helps.

if the antenna is too long just use some cut off switches. When the door reaches a certain point either coming down or going up the cut off switches deactivates the power supply.

Can also be build with a light sensor switch and therefore the timer doesn't have to be adjusted because of daylight savings etc.

Thanks! Yesterday I completed the project! At the moment everything works fine! :) Also my antenna engine, both when extending and pulling back tries to do a few revolutions and then stops. I hope that the night humidity does not damage the antenna and other electronic devices. Thanks again!

pitajames2 months ago


shellheart0072 months ago

Did you cut down the antenna? Mine is super long, just wondered if it is cut down would it still work correctly?


lonesoulsurfer (author)  shellheart0072 months ago

You can cut the top knob off and it won't affect the antenna. Cutting any more might cause it some damage. It doesn't really matter though because when the door is going down (and with it the antenna) and hits the ground, the antenna will stop moving down. You will hear the motor going through a couple revolutions and then stop. This is what mine does and there hasn't been an issue since I first installed over 6 months ago. The antenna's are pretty hardy so it shouldn't damage it stopping before it has completed been completly extended.

Congratulations for the very interesting and useful idea! I have just one doubt.

Is there the possibility that a fox is able to lift the door when it is closed?

It seems that there isn't a safety closure, isn't it?

What about your experience?

lonesoulsurfer (author)  lucio.narducci3 months ago

Nope - once the antenna is down it is held in place by the motor. You can lift it up but it takes some effort and there is no way a fox (or for that matter a dog) could lift it up. It's pretty much like a lock on the door.

Thanks! :) Next days I will try to make this project :)

jdfearl5 months ago

Since the antenna does not fully retract does it stay powered constanly or does it damage it?

lonesoulsurfer (author)  jdfearl5 months ago

Hey there,

Nope there is no issue with the antenna not fully extending. The motor will run through it's cycle and then stop. I've had it running everyday for nearly 6 months and it's still going strong. There pretty hardy things.

Congrats Mate :), Lot of glare in my eyes due to those two shinning medals on top :D

lonesoulsurfer (author)  Tarun Upadhyaya6 months ago

Thanks Tarun. right back at you!

lonesoulsurfer (author) 6 months ago

Thank to everyone who voted - means a lot!

Dorishen6 months ago

you are technical ,do you now how I get a small toy sailboat to go ,with motion detection ,? ,☺

Dorishen6 months ago

you are teknikal do you now houw I get a smaltoy boot to work ,by mosion ditektion ,

Whitesnake7 months ago
Sorry I have now seen he step on why you used it, I missed it as I have just been scanning the web for ideas, I did design a circuit with relay logic latching and limit switches, but having all this in an antenna motor just seems to cut out the hastle. Good post thanks!
Whitesnake7 months ago
What did you use the voltage meter for and switch?
dpruett7 months ago

I've lurked on Instructables for a long time, and I've seen a lot of cool projects I thought I might build but never have - this will finally be the one. Excellent job!

First off, let me say this definitely goes into my 'Why Didn't I Think of That" collection!

Adapting the antenna mechanism is a great idea - thanks for taking the time to share it here.

"When the power is active the antenna retracts and when the green wire (usually green but it could be another colour) is attached to the red wire, the antenna will extend."

I've not owned a car with an automatic antenna, but have driven several over the years. My recollection is that, when you turned the ignition key off, the antenna would retract. I suppose this could be a function of a relay or other controller in the circuit so that the antenna is always powered, but that flies in the face of conventional wisdom. After all once in the retracted position, what need would there be for powering the device - it's at rest.

Now, I have dismantled one of these (just one - no idea which one or the vehicle it had been designed for) and it contained a flexible nylon (appearing, again no certain knowledge as to the composition of the 'plastic' part referenced here) part that appeared to be wound up (drawing the metal antenna mast down) and unwound (raising the antenna) by reversing the polarity to the motor inside that 'can' part of the device.

I mention this as the mast itself my be superfluous in this application - although there is something to be said for the protection it affords by sheathing the nylon 'rope' bit.

As to the power issue, are you saying that, the antenna you used came in the fully extended position and only retracted after you applied power to it? I ask as those sold in stores are retracted in the packages and certainly are not connected to a power source at that time.

Do you maintain that, if you were to disconnect the battery (in the test schematic) that the antenna you have would extend? (or retract) immediately upon losing power?

I am not attempting to be a wise-guy here, just trying to clarify your statement as quoted first above.

Not withstanding your several months of successful operation, my experience with confined poultry suggests that any such mechanism be covered to the extent possible - My thought was that all the parts that you needed to watch be mounted so as to be visible from outside the coop and those parts necessarily inside should be completely covered/protected from the machinations of your flock with only a small opening (hole) for the antenna mast to travel through as it performs the task assigned.

In my part of the world, the days are not of a uniform length throughout the year and my hens follow the sun as opposed to the clock in the coop. This would seem to call for a light-activated switching mechanism as opposed to a timer (and, as has been suggested, a buzzer) though the timer could be used as a 'fail safe' I suppose.

Nice instructable. By the way, how come you folks don't fall up?

lonesoulsurfer (author)  charlessenf-gm7 months ago

Initially I thought the antenna would retract when the power is off but they don't work like this. They need a constant supply of electricity to extend or retract.

Definitely agree which chickens being messy little beasts! I've tried to make sure that the antenna is as high as possible and out of the way from where the chickens roost etc.

What do you mean by "fall up"?

"What do you mean by "fall up"?"

Well, I got from your links to that you were down under.

I think I understand what you meant by "They need a constant supply of electricity to extend or retract.,"

You mean that, ti extend or retract the antenna mast, one must provide power to the device. Such an arrangement does not require a 'constant' connection to a power source, only as, if and when you want to move the mast up or down.

I went to a junk yard this afternoon and found a Honda with an intact (appearing) motorized antenna - but could not get at it as the trunk was locked and the back seat was also locked! They are going to drill out the locks and remove the back seat - then I'll get a shot at it and can ask it the questions directly!


I know someone who's done something quite Similar to this, hat he added was a little alarm or beep that goes off about a minute before the door closes for the night, it didn't take very long for his chickens to learn that beep meant they had to head back in for the night.

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