Hangar door question...

Discussion in 'Hangar Talk' started by ChiefPilot, Nov 22, 2017.

  1. ChiefPilot

    ChiefPilot Pre-takeoff checklist

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    I recently bought a hangar with a bi-fold door. Raising it is fine, as is lowering it, but when the door is coming down, if I press the "stop" button the door continues to lower for 5-10 seconds before finally coasting to a stop. This seems odd and wrong, and potentially dangerous.

    The motor and gearbox is located in the ceiling at the middle of the door; I have a powered lift and can easily have a look at it but not sure what I'd be looking for. I thought there might be some kind of adjustment but didn't see anything obvious.

    Anything in particular to look for? This is an "aerolift" door and was installed in the mid 1990s.
     
  2. somorris

    somorris Pattern Altitude

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    I think you are correct in that the door should stop immediately. It probably has a computer chip somewhere that can be programmed, but you would have to have the right equipment to do that. I say that because my wife is in a power wheelchair, and her chair, when she first got it, did the same thing (i.e. didn't stop immediately). We talked to the technician, and he came out, plugged up his equipment, and changed the programming so that it stopped immediately. If I were in your shoes, I would just call the aerolift door people and talk to them before I did much else. Keep us posted.
     
  3. flyingron

    flyingron Touchdown! Greaser!

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    Cool. Do you have a powered lift rating?

    The question is whether the motor continues to run or whether the weight is just dragging on the brake. Oddly, a lot of hangar door operators are adapted out of commercial garage door hardware. Your brake may be shot.

    By the way, I've never seen a "COMPUTER CHIP" in a hangar door operator. They're pretty low tech.
     
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  4. midwestpa24

    midwestpa24 Line Up and Wait

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    We had a similar problem with one of the Erect-A-Tube hangar doors on our airport. Be careful, because in our case it got worse quickly, to the point that the door would no longer slow down and would "run-away" while closing. It finally got to the point that it would overdrive the motor on the way down.

    For a while they were building the openers without a brake and depended on the resistance of the worm drive gearbox to hold the door. As that gearbox wears out it looses that resistance, and will do what you are describing. The only solution we found was to replace the gearbox, which we had some old spares for.

    The newer generation has an external brake again for additional safety.