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Thread: Stick shaker

  1. #1

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    Stick shaker

    I have had my stick shaker installed in my Grumman for about a yr now and have gotten very used to it. Recently I did a photo mission for a friend and we spent an hour with the canopy back at 1k ft and just above the stall speed. I felt very comfortable "flying the shaker". I have it set about 5 knots above stall and while busy looking at our targets my attention was never diverted away from outside.
    If I had an AOA I would have had to keep my eye on it the whole time.
    I understand the industry is trying to sell another must have accessory but as for me and my airplane, we are going to look out the window and when we get a little slow I will feel the buzz just before the wings start to shake and things go wrong.
    The little vibrator motors are all over ebay for less than 10 bucks, clamp it to your column, hook it to your stall horn.
    Don't fall.

    Ray Toews
    Fort Vermilion AB

  2. #2

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    Go for the AOA. Hook your stick shaker to that. Then, no worries whether you're light or heavy.

  3. #3

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    Quote Originally Posted by rv7charlie View Post
    Go for the AOA. Hook your stick shaker to that. Then, no worries whether you're light or heavy.
    +1

  4. #4
    rwanttaja's Avatar
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    Sounds like a good entry for the contest:

    http://www.eaa.org/en/airventure/eaa...ety-innovation

    (Pssst Hal: The http://www.foundersinnovationprize.org link in the above press release doesn't work....)

    Ron Wanttaja

  5. #5

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    Ray: Great post and good use of low cost technology that works well! Ironically, your post shows the strong need for education on AOA. Your stall horn is AOA-based. In technical terms, the certificated (probably Safe Flight) vane/flipper switch makes electrical contact when the stagnation point goes below/behind it. This makes the horn go off (... and in your case, the stick vibrate). Good use of technology :o) and thanks for sharing!

  6. #6

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    I would love to claim it but I read about it on the VAF. I like the Safe Flight vane, adjust it for 5 k above stall speed. Aircraft Spruce has them for $165. I'm installing one in my new Zenair wings. Different weights change the stall speed but it still goes off at the same angle.
    AOA that I have researched don't seem to work with flaps and if they do they use a calibrating computer to provide a bias. More stuff to go wrong. The ones with the vane on the side would work, but a prop on the nose makes that difficult. Has to be mounted under or in front of the wing. Works fine on jets.
    Back in my 417 SQN days that was one of the pre takeoff checks, move one vane, the pilot felt the shake, go around the other side and it kicked.
    The AOA's with the air pressure sensing would be fussy to adjust. My MGL EFIS has a diagram to drill two holes in the leading edge, unobtrusive but not easily adjustable. Also the air pressure ones would need some type of electronics to send 12 volts?? to a gauge.
    This is one of those things that should be installed in every spam can out there, most of them have the little paddle switch already, (except some Cessna's which used the air horn). Easy to hook up, I just wired mine to the stall horn, 1/2 hour job, cost me $8. My Cheetah is OM so I just made an entry in the log book. No gov't oversite.
    The way it should be.
    Ray
    Last edited by raytoews; 09-04-2015 at 09:35 AM.

  7. #7

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    Ray: Agree with all you say. No AOA will work with flaps as you mentioned, though. Ironically, the stall AOA does change with flaps (so a flap input is required) ... the stall AOA is LOWER with flaps. So one could get around this issue if they set a single input AOA system up by using the flaps DOWN data. It would be conservative for flaps UP.

  8. #8
    cluttonfred's Avatar
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    This would be a great project for a little Arduino microcontroller using tiny haptic (vibrating) motors like these installed directly in the stick grip(s) or yoke(s) along with a visual indicator (bright flashing LED?) at the top of the instrument panel.

    Name:  1201-01(1).jpg
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    http://www.adafruit.com/products/1201

    For a flapless plane you could use a homemade vane- or paddle-type AOA with a single contact switch at the critical angle. For a flapped plane you would need a more sophisticated AOA sensor with a potentiometer to provide variable AOA indications, and some way of determining flap position, perhaps another potentiometer connected to the flap handle, crank or indicator if there are multiple flap positions or just a couple of contact switches if you only have two or three possible positions.

    The Arduino microcontroller needed for such a simple application would only run about $10, so the whole project would only cost about $25-50 including the option of a small battery backup. It could even be used in a plane without electrics with a 9v battery or little rechargeable battery pack.
    Last edited by cluttonfred; 09-23-2015 at 02:42 AM.
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    Matthew Long, Editor
    cluttonfred.info
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  9. #9

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    Thatis very cool.

    Slip it under your rubber grip so it buzzz's right into your hand.
    That will be the next one I do.
    No need for electronics, a wing stalls at 15 degrees, weight just changes the speed at which it stalls.
    When the buzzzer goes off you are at fifteen degrees, it startles you,,,, you push and don't die.
    KISS works.
    This is one of those simple things the govt should approve NOW with no restrictions.
    Is there anyone from Transport Canada, the FAA or ICAO out there? Get off your fat borocratic ass and do something productive,,,,,today!
    They want to keep us safe from ourselves,, do something to reduce the loss of control accidents, this will do it.


    But I digress,,,,

    Ray

  10. #10

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    Quote Originally Posted by raytoews View Post
    Is there anyone from Transport Canada, the FAA or ICAO out there?
    Yes. FAA, TC, EASA and ASTM. We're working on it ... just need to get it through the government lawyers.

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