UKC

Any DIY aficionados in the house? 

I've got a chicken coop in the back garden and want to set up an automatic door opener so that I don't have to get up at the crack of dawn on my days off to let the chickens out.

You can buy automatic door opening kits, and there's plenty of youtube videos showing how to make them yourself, but these all seem to involve lifting the door vertically. Our coop is homemade out of some old pallets and an old compost heap. The door swings open like a normal door, there isn't room to lift the door vertically.

What I have in mind is to fit a spring to the inside of the door so that it swings open on its own. I then want to have a bar that holds it shut rigged up to some sort of timing device so that I can set a time and it will retract the bar, allowing the door to swing open.

Does that make sense? Anyone have an idea how I could build such a device? The coop is quite a long way from the house so it would need its own power supply.

In reply to MikeR:

Sounds like you need some basic electronic knowledge.  A timer and an actuator to move something like a latch or catch, re-chargeable batteries, solar panel to keep power topped up.  Might also need some basic 'programming' skills to make it all work which implies some sort of basic CPU ad microprocessing unit - Arduino would be a sensible starting point.

I am sure you could buy a kit that would do something close enough to modify - an automatic feeding device for a cat or fish tank perhaps?

In reply to MikeR:

There are a thousand and one ways to achieve this, which you choose would come down to your skills, interests and what you have available already.

A totally mechanical solution would maybe use a wind up alarm clock with the long hand removed, set up so the hour hand trips a release lever at the desired time. Alternatively one of those programmable cat feeders could be hacked about to do the same job.

A very simple electrical solution would perhaps use a solar panel to power a small solenoid tripping a release lever when the sun comes up.

More sophisticated solutions based on electronics range up in complexity from a modified digital alarm clock to whatever you can imagine.

A piece of string run from the catch back to the house would probably also do.

jk

In reply to MikeR:

12v battery (bring it indoors to charge or get a solar panel if the suggestion below actually works)

Cheaper (£10 total for two items below) if you look around but for example. 

https://www.amazon.co.uk/SODIAL-Digital-Power-Programmable-Switch/dp/B00F4M...

https://www.amazon.co.uk/Adafruit-Lock-style-Solenoid-12VDC-ADA1512/dp/B01G...

Ideally you only apply power to the solenoid for one or two seconds but the timer above does 1 minute interval.

 

 

 

In reply to jkarran:

Thanks, I'm liking the solenoid idea, could make one to pull the bolt back. Although the alarm clock idea has merit for its Wallace and Gromet style!

In reply to elsewhere:

Thanks, that looks pretty good. Any idea if there'd be a risk of burning out the solenoid powering it for too long?

In reply to MikeR:

I think you need a Raspberry Pi and some voice recognition software. Then you need to train the chickens to "ask" for the door to open.

In reply to MikeR:

To keep the solar panel size/cost down you'll have very little power available, the most a solenoid will do is trip an already sensitive release mechanism, it won't pull a bolt out of a door.

jk

In reply to MikeR:

It's only designed for up to 10 seconds activation so I'd expect it to get warm. I think 60s once every 24 hrs would be OK but you would have to test it without burning down your house or chicken shed.

If necessary try a 6 ohm 3 watt current limiting resistor (approximate numbers) in series with the latch and see if it still works, that will reduce heating from 8 Watts to 4.5 Watts

TECHNICAL DETAILS from https://www.adafruit.com/product/1512

12VDC (you can use 9-12 DC volts, but lower voltage results in weaker/slower operation)

Draws 650mA at 12V, 500 mA at 9V when activated

Designed for 1-10 seconds long activation time

Max Dimensions: 41.85mm / 1.64" x 53.57mm / 2.1" x 27.59mm / 1.08"

Dimensions: 23.57mm / 0.92" x 67.47mm / 2.65" x 27.59mm / 1.08"

Wire length: 222.25mm / 8.75"

Weight: 147.71g

A timer that works to 1 second interval would be ideal.

 

In reply to MikeR:

12v battery running a linear actuator via a time switch? 

a quick ebay shows a 12v digital programmable timer about a tenner and a 12v linear actuator about £35. 

You have to make a weather proof box to house the gubbins in and occasionally charge the battery

In reply to MikeR:

If you had a light spring pulling the door it would only have to power once to release the door.

The door would release (latch on timer) in the morning be held open by the spring and then when you lock them up at night you shut the door?

In reply to MikeR:

Liking the spring idea, not so keen on the solenoid.
How about a bar latch to keep the door shut and a motor with a disk on the end (with the hole offset) under the latch.
Motor turns disk, disk raises latch and door opens (microswitch under disk to detect position).

In reply to elsewhere:

Put a normally closed switch in series with coils input, when the door opens, the switch opens, the coil circuit is broken, you don't need any timers then.

To the OP is the chicken coop near a source of electricity our not?

Car parts are always a good choice to re-appropriate for this sort of thing, and they mostly 12VDC so old car battery is a good source of power.

If it's near 240V socket I'd use a wireless socket (WeMo) which you can set to do things at particular time e.g. 10minutes before sunrise (you need to set you location in the Wemo) and have this fire off a solenoid and a spring loaded door. This set up allows you to open the door with your phone at any time too, so commissioning will be easier.

We demand photos of the working model.

In reply to krikoman:

Good idea - a nice simple solution.

A burglar alarm door/window switch & magnet is purpose built for that.

 

In reply to elsewhere:

I specialise in simple

In reply to MikeR:

I've tried this sort of thing with solenoids, and it's tricky to make it reliable as they don't provide much force so you have to get the mechanism very slick.

How about an eectric tailgate lock from a car? Most cars nowadays have them, so you should get one off eBay for a few quid. Spring load the door and click it shut as you would a car door. Apply 12V and it pops open. They have built in microswitches so only run for as long as required, so you don't need to worry about leaving the power connected too long. eBay will also get you a timeswitch.

In reply to jkarran:

Good call. Cheap, reliable, simple.

 

In reply to MikeR:

I had a bit of a random thought that you could rig up something using water, where you calculated the flow of water from a high up container, which trickled into a hollow vessel which acted as a weight, which when it was heavy enough pulled down on something which pulled up on something (thanks to leverage) which released the catch on the chicken coop.

The only problems would be winter, and and perhaps figuring out how to stop the water from trickling once it has done it's job. The weight pulling down to release the latch, could also pull down on something which releases a spring to return the water container to being upright, or else you could calibrate it so that excess water after the door opens isn't a problem, thanks to only using enough water to do the job.

Edit: On reflection, it could be quite pleasing to get right and see working, but other options are probably simpler in real life.

Edit 2: I suppose you could have some piping with a tap involved, so you could alter the flow rate until it was just right, but that doesn't solve the freezing problem, unless you use cooking oil or something else other than water, a tap isn't as refined as having it calculated just right too, though it's only a chicken coop.....

In reply to MikeR:

Thanks all, some great suggestions coming through. Interesting idea to train the chickens to use voice activation!

I've got an auto cat feeder, could have a go at taking that apart to see if it's useful. The cat manages to outsmart it anyway whenever we've used it.

In reply to krikoman:

Nowhere near any power source, so any power would have to come from battery or solar, and as it's under a big tree solar would need to be some way off too.

Thanks for the suggestions. I'll supply photos once finished!

In reply to Timmd:

A nice elegant sounding idea, and it doesn't require any power either which is a bonus. I've got a few old climbing pulleys lying around that could work. If I rigged it right, it could lower to ground level to give the chickens a drink as they came out in the morning.

Only down side is that they get up around sunrise, so would need to keep calibrating it through the year.

In reply to MikeR:

You could go mechanical.
Have some kind of pressure plate, so when sufficient number of chickens congregate by the door in the morning, it trips a latch and lets them out.

 

In reply to MikeR: Thank you. I really want to make something like I've suggested just for the pleasure of seeing it function now. If I didn't have more urgent things to do...  

Edit: I guess that's where the tap could come in, in calibrating the flow rate in line with the length of time between dusk and dawn. You could use a container with the volume marked on the side (like a measuring jug, but not one), and have it so X amount flowed each hour by using the tap. I guess the weight would need to be big enough to hold the winter volume, and heavy enough to work with the summer volume too. Once you knew how much would flow per hour, you could alter the amount for the length of darkness. 

Edit 2: I'm more enjoying working it out than thinking you need to know, in case you already know how to suck eggs.

If you had a bar which pivoted, which the vessel-weight was hanging on, you could perhaps have a means of sliding another weight along it so that it balances right...

In reply to Timmd:

Oil sounds great, you could syphon some off into a pan, heated by the solenoid, drop and egg in and get it fried for free, just in time for breakfast.

In reply to MikeR:

Do you have a fox problem? If not why worry about closing them in, if you do put a covered enclosure around the chicken coop and let them out of that at your convenience.

In reply to cander:

Never seen any evidence of foxes, although couldn't rule them out.

Very new to keeping chickens so I just assumed that you're best to shut them in at night.

In reply to MikeR:

Yes, keep them shut in at night.  But I wouldn't worry about having to get up at the crack of dawn to let them out.  All ours get let out about 8am in summer - or earlier if we are up - but certainly not really early.  Unless you call that time early.

 

In reply to MikeR:

With a bit of patience, you could train one of the local wild foxes to open the door for you?

Failing that, could have a spring that constantly pulls the door open, and an electro magnetic door lock that's hooked up to a timed power supply (like one of those things you turn lamps on and off with when you're on holiday).  You might need to run a long power lead into the house, which is a pain but super easy.

In reply to MikeR:

We have ours in a chicken wire enclosure about 4 x 8 meters - I never close the door on the chicken hut - they roost in there and lay there, then wander about the enclosure until I let them out when I walk the dog in the morning (between 07:00 and 09:00 depending on what’s happening that day). They wander back into the enclosure at dusk and I close them in when I take the dogs for last pee at night.

 

In reply to MikeR:

I'm loving all these rude goldberg ideas, hilarious reading I really LoL'd irl.

 

I think you should rig up a really long string on some pulleys that goes into your bedroom so you can do it manually from in your bed, Yes you still have to wake up early but you don't have to get out of bed...!

In reply to cander:

Same here. Fox proof enclosure in a corner of the garden behind the sheds. We only drop the door on the chicken shed in bad weather, and let them roam the garden when we're in. Obviously depends on how much space you have and how tatty you mind your garden looking!

Edit: Although I'm now going to build the most elaborate and impractical door opening system now I've read the examples above!

In reply to Bellie:

Same with my brother and the chickens on his holiday let site, they just let them out when they get up between 7 or 8 in the morning. 

In reply to MikeR:

My hens had a fully enclosed "aviary" with their coop inside so we're never shut in the coop.in the mid summer they would sleep on the roof!