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Automatic chicken coop door.

Discussion in 'Projects' started by JDM_, Jul 15, 2013.

  1. JDM_

    JDM_ New Member

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    Do you guys think this design will work? I based it off the Z axis of RoBo using a threaded rod to raise and lower the door. A small Arduino board will control it using a light sensor to activate it at sun up and sun down. Li,it switches will stop it at the top and bottom.
    ImageUploadedByTapatalk HD1373907304.144105.jpg



    Sent from my iPad using Tapatalk HD
     
  2. Mike Kelly

    Mike Kelly Volunteer

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    Would work in principle. Though a linear actuator would be faster acting and probably comparable in cost to the motor + accessories to turn circular motion into linear
     
  3. Leon Grossman

    Leon Grossman Active Member

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    Is there any risk of squishing chickens? In that case, you'll need a safety sensor. Also, is there any worry of chickens being trapped on the wrong side of the door?
     
  4. JDM_

    JDM_ New Member

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    I have thought of a sensor but I don't think it will be nessesory. The door will open and close slow and they all go back to the coop before dark because that is where they feel safe. I can just set the Arduino to close 15 min after dark.

    Not sure about a linear actuator but I will look into it. The one thing I like about this design is that the threaded rod will hold the dorr closed to keep preditors out.
     
  5. wrdutcher

    wrdutcher New Member

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    JDM, that is a interesting idea you have, you should consider marketing it? Maybe on Shark Tank. LOL
    Could even be used for pet doors. Here in Florida every critter knows that a pet door is an open invitation to dinner.
    Another possible solution to making the door safe would be attaching the threaded rod to a block that moves up and down in a slot in the door, allowing the door to hang on the block instead of being attached to it. This way the chicken would only have to contend with the weight of the door and not the pressure of the drive linkage pushing down on them. When closed the block will continue to move down to the end of the slot before hitting the limit switch thus holding the door down. At a slow rate I would think that a slot of a couple inches would be enough. Great project for a 3d printer.
     
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  6. JDM_

    JDM_ New Member

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    Can anyone recommend a type motor for this project?
    I don't know much about motors and I'd like to get one soon... It will only have to life a 1/2" thick piece of plywood.
     
  7. wrdutcher

    wrdutcher New Member

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    You need to determine the max load the stepper motor will see, then select a motor that can handle that torque. Calculating max torque involves unwrapping the the screw thread to form a right triangle, accounting for friction and the weight of the door as the motor pushes the load up or down the hypotenuse. The equations for these calculations can be found at: "http://en.m.wikipedia.org/wiki/Leadscrew"
    under the Mechanics section. The site explains things nicely but the math is intense.

    However, I have found in designing control systems, calculations only get you in the ballpark. A simpler method to determine the torque, would be to build the door. Then use a good torque wrench to measure the maximum torque seen when raising the door. Rotate the screw smoothly and slower then you plan on running the stepper, so that the friction element can be measured. Do this several times, record the max torque measured, multiply by 1.3 or 1.4 and choose a stepper motor that will handle that torque. Since I am a retired EE, are there any mechanical engineers with additional insight? Please chime in.

    Edit: Thinking about this, a DC motor with a pwm speed control would be a better choose, and with a little electrical know how could be controlled with a simple circuit. But a processor board would be more flexible.
     
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  8. tesseract

    tesseract Moderator
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    How about an automatic window opener for cars it is pretty much already setup to run with a limited amount of travel in both directions those are cheap around here and you can add any cutoff switch so nothing trapped under turn it on and the door closes reverse it and it opens just like a car window. It sounds a lot more simple and should work just fine.
     
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  9. wrdutcher

    wrdutcher New Member

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    Great idea, can easily handle the weight of a small piece of plywood and can be controlled by an Arduino board using a couple small relays or driver chips.
     
  10. Mike Kelly

    Mike Kelly Volunteer

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    Agreed. A stepper motor would be overkill for this application, though I don't think you need to have a motor driver circuit for this application as it doesn't require speed control. A simple on-off is adequate.

    I would recommend going through the calculations of torque to get you a ballpark estimate of the required torque.

    So what it comes down to is speed vs cost.

    http://www.mcmaster.com/#dc-gearmotors/=nocdk1

    If it was me I'd go with the compact DC gearmotor. Good torque for the $. Granted the higher torque you need the slower it's going to run. The minature dc gearmotor is also great for this application if you're willing to pay the premium.

    Chances are good you can lower the friction by using oils etc on the drive shaft. This will mean you can use a higher speed, lower torque option.

    You'd have to calculate the number of threads per inch and determine if that closing speed is something you can live with. Then find a motor that has the speed and torque you need. If you don't want to go with a gearmotor you could gear a motor yourself if you're ok with exposed gearing or covering it.
     
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  11. JDM_

    JDM_ New Member

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    Thanks mkelly.... I will build it the door and test the torque ASAP. My coop is far from my house. I was thinking about putting a small solar panel on it and run this off battery. To run it from battery i get a 12v motor right?
     
  12. Mike Kelly

    Mike Kelly Volunteer

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    Yeah most solar cells charge 12v batteries.
     
  13. JDM_

    JDM_ New Member

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    Project update:

    I've cut, sealed, and assembled all wood parts. The door moves smoothly up and down. Designed and printed the door mount with threaded nuts at top and bottom. My arduino boards should be in soon....
    I'm still looking for a motor and need to order some limit switches. I might try to find a drill on Craigslist or at a garage sale.

    [​IMG]
     
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  14. JDM_

    JDM_ New Member

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    Project update:

    - Designed and printed limit switch mounts.
    - found old cordless drill to use motor out of. Tested it and it will easily raise and lower the door.

    Next step will be to figure out how to mount the motor.

    ImageUploadedByTapatalk1375314018.978911.jpg
    ImageUploadedByTapatalk1375314031.483395.jpg
     
  15. Mike Kelly

    Mike Kelly Volunteer

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    Are you gonna take that drill apart or just use as is?
     
  16. JDM_

    JDM_ New Member

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    I am going to probably take it apart. Will be designing a mount for the motor this week.
     
  17. Soupaboy

    Soupaboy Active Member

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    has this men finished? how is it?
     
  18. Das Wookie

    Das Wookie Active Member

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    I'd be interested in your progress as well. I've been considering something similar for our chickens and ducks... but I'd need to open their pen door which is a 10'x20' dog kennel. It's heavy guage welded wire panels and large doors, so I'll probably need a spring or something. I'm still considering designs. I'm more interested in getting the door to open, and I'll be responsible for closing it up at night and making sure everybody is in and boxed up, as well as re-lowering their feed containers which I suspend from rope from the kennel roof. I keep it up during the day so they have to forage rather than just sit around eating kibble all day long. LOL
     
  19. mudassar1

    mudassar1 New Member

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    I want to buy a chicken coop and run, to house 3/4 hens. I like the raised coop design,mainly as vermin coundn't take up residence underneath, The nest box sits on the side, but will they get too cold in winter?
    No option to get one DIY'd , so its a ready made.
    If anyone has any experience of the shop bought kits and their robustness please share . The gimicky and expensive eglu is not for me.
    Any thoughts?
     

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