Chicken Door Coop Controller - novice help please

Thread Starter

mat03

Joined Jun 3, 2020
3
Hi All, first post. Hopefully I've come to the right place. If not please let me know where.

I would like to create a waterproof controller to raise/lower a guillotine style sliding door (slowly :) ) on my chicken coop using a light controller or a timer. Could also be horizontal but I assumed vertical would be easier. The door will be about 12cm x 15cm made from plastic or steel sheet. It will need to raise at dawn and lower at dusk by 15cm. Powered by AA or a 9v battery. I would prefer not to have any contact switches in the door brackets and have this done all via the contained controller - not sure if that is possible, else how is the mechanism stopped when the door is at the top or bottom?

I could of course buy an off the shelf product but where is the fun in that. Plus they are between £100-£180 when adding in the door as well.
For reference - https://www.ebay.co.uk/i/303126025322

https://www.ebay.co.uk/i/281258322535 - I also found this component for reverse polarity but appears it 12v, which it too high since I won't have mains power (and I don't want to use 8 AA batteries). Would use a car wiper motor from the looks of it.

I've considered a light switch, with a geared motor and pulley wheel with thread/fishing wire (so reverse motor polarity for the door to go up and down) as a winch, but this is where I stop. I have no idea what components I'd need, how they'd work, or which to buy.

Apologies I am a complete novice when it comes to electrical components, but I'd still like to give this a go. I have a few bit some basic automotive electrics.
Soldering iron - check
multimeter - check
I've bought a light controller kit, but nothing else.

Anyone able to assist?

Thanks in advance,
Mat
 

SamR

Joined Mar 19, 2019
2,125
The problem you face is the battery power to raise and drop the door. The light-sensing is a snap.
 

Irving

Joined Jan 30, 2016
402
How heavy is the door? Its inherently do-able but as said battery power is the issue - AA/PP3 won't cut it. Whereabouts in the world are you? Is solar-powered battery recharging an option maybe?
 

Thread Starter

mat03

Joined Jun 3, 2020
3
A few of the previous discussions on that subject.:
Chicken Coop list
thanks I'll take a look. I couldn't find much via Google but didn't think to search the forum :oops:
How heavy is the door? Its inherently do-able but as said battery power is the issue - AA/PP3 won't cut it. Whereabouts in the world are you? Is solar-powered battery recharging an option maybe?
it won't be heavy. think I have some aluminium in the shed. 200g-Max 500g

I'm based in the UK so it's certainly not sunny all the time
 

Irving

Joined Jan 30, 2016
402
ok, working on 500g, energy to raise door 15cm = m.g.h = 0.5 * 10 * 0.15 = 0.75J, assume raise takes 5 secs = 0.15 Watts @ 30% efficiency in motor/drive mechanism = ~0.5 Watts. A 5v/100mA motor with a simple gear train and a pulley/cord or gear/rack arrangement will do the job plus some simple locking mechanism to keep door raised, with a solenoid release. Suggest door runs, for example, on v-pulley against vertical aluminium angle, or could all be 3d printed.

A standard 5v 2000mAH (10W) powerbank would hold enough charge for a weeks worth of opening and a 50W solar panel with clear view of sky would easily maintain enough charge on a day-to-day basis even in UK
 

Alec_t

Joined Sep 17, 2013
11,291
Welcome to AAC!
The door will need to be pretty robust and considerable force may be needed to move the door. There will be a lot of friction when the door runners/guides get filled up with dirt and chicken crap. The door will also have to withstand considerable force when it is half-closed and chickens try to force their way in/out.
 

Irving

Joined Jan 30, 2016
402
The door will need to be pretty robust and considerable force may be needed to move the door. There will be a lot of friction when the door runners/guides get filled up with dirt and chicken crap.

The door will also have to withstand considerable force when it is half-closed and chickens try to force their way in/out.
All good points

12cm x 15cm door (from OP) weighing 500gm would be about 8mm thick - can't see a chicken pushing through that, but then i know nothing about chickens :D
v-pulley runners can stand a lot of sideways force (use them on cnc machine and withstand several kg cutting forces no problem). Crap issue is tricky, but maybe some sort of brush/scraper either side of pulley to clean runner? maybe use some light beam detector to check no chicken in doorway when closing?
 
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Externet

Joined Nov 29, 2005
1,493
I always suggest this way:
The vertical sliding door pulled up by a string.
The string wound 4 or 5 turns on the shaft of a DC motor (~ 2-3mm diametre, not a pulley), placed well above the door.
The other end of the string to a counterweight, makes the door much less heavy and less energy needed to lift it.
The electrical supply is a solar panel always connected to the motor and capable of pulling up the contraption at dawn light level and keeps it being stall-pulled all day. At dusk, there is not enough energy generated and the counterweight closes the door.
No batteries, no switches, no springs, no timers, no latches, no sensors, no complications. The stalled motor just helps the counterweight down and nothing else. Door can be as heavy/sturdy as desired.
No sunlight ----> door weight wins closing.
Sunlight ----> motor helps counterweight to keep door open.
 
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Irving

Joined Jan 30, 2016
402
I always suggest this way:
The vertical sliding door pulled up by a string.
The string wound 4 or 5 turns on the shaft of a DC motor (~ 2-3mm diametre, not a pulley), placed well above the door.
The other end of the string to a counterweight, makes the door much less heavy and less energy needed to lift it.
The electrical supply is a solar panel always connected to the motor and capable of pulling up the contraption at dawn light level and keeps it being stall-pulled all day. At dusk, there is not enough energy generated and the counterweight closes the door.
No batteries, no switches, no timers, no latches, no sensors, no complications. The stalled motor just helps the counterweight down and nothing else. Door can be as heavy/sturdy as desired.
No sunlight ----> counterweight wins closing the door.
Sunlight ----> motor fights counterweight from winning.
That's a potentially neat solution and I agree about the counterweight, though motor still has to be powerful enough to overcome friction and inertia of door.

BUT I don't understand how the counterweight works; according to your first comment opposes the weight of the door (and therefore assists opening it), but then you go on to say it closes the door (which means it can't then be a counterweight). Also if door and counterweight in equilibrium so motor only has to overcome friction/inertia then light = open but no light equals no movement....

Another potential flaw might be that there will be days where its so overcast/cloudy that the door won't open. How big/many solar panels are you advocating?
 

drc_567

Joined Dec 29, 2008
844
Another scheme would use a length of ACME Threaded Rod, and it's mating nut to raise and lower any substantial door section.
ACME Rod
This would provide more lifting and lowering force than many other less powerful methods, due to the mechanical advantage provided by the screw type threads. The main design effort would be shifted to motor control, that is, starting and stopping, reversing the motor at appropriate times. A piece of plastic split loom sleevng from the auto parts store might be enough to keep the screw threads from becoming fouled. Hall effect devices on the fixed runners, and magnets glued on the door could serve as position limit switches. You would need a method of reversing the motor rotation direction, however there should be a way to accomplish that task.
 

Irving

Joined Jan 30, 2016
402
Another scheme would use a length of ACME Threaded Rod, and it's mating nut to raise and lower any substantial door section.
ACME Rod
This would provide more lifting and lowering force than many other less powerful methods, due to the mechanical advantage provided by the screw type threads. The main design effort would be shifted to motor control, that is, starting and stopping, reversing the motor at appropriate times. A piece of plastic split loom sleevng from the auto parts store might be enough to keep the screw threads from becoming fouled. Hall effect devices on the fixed runners, and magnets glued on the door could serve as position limit switches. You would need a method of reversing the motor rotation direction, however there should be a way to accomplish that task.
Yep, could be done that way, I had something similar on a furnace/kiln door. Mechanically/physically a lot harder to accomplish though and, being outside, you'd need stainless steel rod/nuts or the whole thing would rust solid in a week...

A string pull, or a belt-driven solution, is much easier to do mechanically.
 

drc_567

Joined Dec 29, 2008
844
Yep, could be done that way, I had something similar on a furnace/kiln door. Mechanically/physically a lot harder to accomplish though and, being outside, you'd need stainless steel rod/nuts or the whole thing would rust solid in a week...

A string pull, or a belt-driven solution, is much easier to do mechanically.
... Thinking an Arduino could stand by for a light sensor signal at dawn and then turn on an H-bridge to raise the door for the day. At dusk, a dark sensing signa! would initiate the lowering sequence. Another detail might be a horn of buzzer to alert the critters to start getting inside.
As far as screw rod materials, ... can't rule out stainless steel availability.
 

Externet

Joined Nov 29, 2005
1,493
I see the wrong conflictive mental fart wording, thanks. :oops:
the counterweight closes the door.
Should say 'the door weight closes it'
The counterweight alone is not capable of lifting the door. Needs help from the motor pulling in stall mode to overcome the door weight and lift the door. When the motor is not working, the door closes.

How many solar panels --- whatever the chosen motor needs at all sunlight conditions. Friction from a poorly made door is a problem not to be confused with lack of motor power; inertia to be tailored with motor capability.
 
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Alec_t

Joined Sep 17, 2013
11,291
Bear in mind that unless the hen coop is in a totally netted enclosure the door mechanism is likely to be tested by foxes with cunning and considerable paw strength.
 

djsfantasi

Joined Apr 11, 2010
6,427
... Thinking an Arduino could stand by for a light sensor signal at dawn and then turn on an H-bridge to raise the door for the day. At dusk, a dark sensing signa! would initiate the lowering sequence. Another detail might be a horn of buzzer to alert the critters to start getting inside.
As far as screw rod materials, ... can't rule out stainless steel availability.
If you use an Arduino, you might as well use a Real Time Clock (RTC) and a table of sunrise/sunset times. Then you don’t have to worry about sensing light levels and rainy days.
 

drc_567

Joined Dec 29, 2008
844
If you use an Arduino, you might as well use a Real Time Clock (RTC) and a table of sunrise/sunset times. Then you don’t have to worry about sensing light levels and rainy days.
That might be one way to go.
... The only other selection to make is a DC motor. If a 4 amp DC current is enough, then one of the store shelf Arduino H Bridge shields could be used as the motor driver. This specification may require a closer examination in order to achieve sufficient lifting force.
Arduino H-Bridge
 
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Tonyr1084

Joined Sep 24, 2015
4,535
If you're set on a particular way to achieve your goal - I'm good with that. But if I were to approach this issue I'd use a solar panel to operate a 12 volt relay. Relays have a habit of requiring a certain amount of voltage to pull in. Typically, some of the 12V relays I've messed with require a minimum of around 9V to pull in and will hold till voltage drops off to around 3.5V. This would give a fairly nice hysteresis controlling a relay. The batteries can be anything appropriate to the motor voltage, be it 6 or 9 volts. But you wouldn't want solar to power the door. It might not close all the way.

When the panel sees sufficient sunlight the relay is triggered. The motor will run till the Open Limit switch is activated. Once activated, the motor is isolated from the batteries, preventing them from being drained. I'd go with a slide to open as opposed to a lift to open arrangement. That way the door can't slowly close itself under force of gravity. Should a passing cloud drop the solar panel voltage, the relay will continue to hold until the panel voltage drops sufficiently to drop the relay. When the relay drops out the door will close. Once the Close Limit switch is activated, again, the motor is isolated from the batteries. EDITING DRAWING. SCREWED SOMETHING UP. WILL REPOST WHEN CORRECT. SEE POST #23 FOR SCHEMATIC.
 
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ericgibbs

Joined Jan 29, 2010
10,039
hi,
A see a number of suggestions about motor sizes, has anyone considered balanced counter weights, as per regular elevator design.?
E
 

Tonyr1084

Joined Sep 24, 2015
4,535
Welcome to AAC!
The door will need to be pretty robust and considerable force may be needed to move the door. There will be a lot of friction when the door runners/guides get filled up with dirt and chicken crap. The door will also have to withstand considerable force when it is half-closed and chickens try to force their way in/out.
This, though I hadn't considered it, can be overcome by a hanging door, much like the sliding barn doors that hang on a steel track with the door hanging via rollers. Easy to move side to side and no chance of chicken mess from fouling the track. All you'd need is a bracket at the end of the closed position to keep the wind (or chickens or raccoons) from opening a hanging door.
I don't understand how the counterweight works
Suppose the door weighs 200g (in a hanging configuration). A motor would have to lift all that weight. But if the door was counter balanced with a 150g weight then the motor only has to work hard enough to lift 50g. Upon loss of power the heavier door will pull closed.

Both good ideas. My suggestion is just one more way to consider the task.
 
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