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Automatic Window Lift

  1. Mar 17, 2017 #1


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    Hello all!

    I'm an electrical/controls engineer by day and farmer by night. I need some insight on an issue I'm having at the farm.

    We have a greenhouse where I've setup automatic temperature controls. A small PLC reads temperature in the greenhouse. If the temperature gets too high, we open the vent shown in the attached pictures. When the temperature goes low, we close the vent.

    The motor I'm using is a wench mounted on the wooden platform inside the greenhouse. I can change ropes as needed.

    The vent is made of plastic roofing material. It's actually 4 sections I tied together with a metal pole in order to lift all at once. I can cut this up as needed but I would like not to add any additional materials as to save money. I have other pieces of scrap metal to use as well. These are more metal poles like you see in the pictures.

    The mechanical setup I have right now does not work. In the pictures from the outside, you can see two poles in the ground. I was trying to lift from the outside. Ideally I'd like the movements to happen from the inside to avoid weather wear.

    Thanks for reading this far! I can build anything but just don't have an idea of how to make this one happen. Please offer some help! I'm open to completely new ideas or fixing what exists while keeping spending low and design as simple as possible.

    Thanks for any help in advance.

    Attached Files:

  2. jcsd
  3. Mar 17, 2017 #2


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    Science Advisor
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    Hello EE_, :welcome:

    You don't mention in what respect
    Could a counterweight improve the situation ? All you have to do with the wench is pull that down or let it swing up again...
    (I assume strormproofing the design isn't your main concern ?)
  4. Mar 17, 2017 #3


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    Staff: Mentor

    Welcome to the PF.

    I'd be inclined to just use a small motor and screw drive with two limit switches to do this. What PLC are you using for control?
  5. Mar 17, 2017 #4


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    Staff: Mentor

    Like the upper drive in the picture below. Inside the greenhouse in the middle of the window, one end of the screw is fixed with a bearing onto the lower part of the vent window frame, and the motor is fixed onto a small platform attached to the lower window sill. The platform with the motor should be free to tilt through a few degrees as the window is pushed open, since the point of attachment on the bottom of the window will rise slightly as the window is pushed open. One limit switch will sense when the vent window is all the way closed, and the other will sense when the window is open enough (via the screw position or some other means).

    Would that work?

    http://www.controlsdrivesautomation.com/orgfiles/ZORGF000011/CDA/images/STOBER PRODUCT 1BALL.png
  6. Mar 17, 2017 #5


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    It would help if you would describe what you mean by "it does not work". How are the current ropes arranged so as to lift the bottom of the panel set and are the connection(s) to the panel (at the center or each end?); and, is the panel set rigid enough to be lifted by either pulling or pushing on the bottom corners at each end of the panel set?
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