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fiebichpv |
February 11, 2019, 2:58pm |
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A/B Plans #112 has 1008 hours as of 02-09-2015 Ace
Posts: 1,694
Time Online: 36 days 13 hours 20 minutes
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Shrinking AirBike?
For the past 20 or so years, I have noticed that many of my favorite clothes have been shrinking. Most to the point that I can not wear them anymore and have had to go to progressively larger sizes. This is unfortunate because I really liked my bell bottoms, leisure suit, tie-died & paisley shirts, and puffy ski jacket. Even my winter gloves have had to be exchanged for mittens. Fortunately my flip flops have not shrunk or else I would have to wear old man slippers.
But now what I have come to realize is that wood and steel also shrink...a lot. And it isn't just because it's cold in Kansas during winter. Unfortunately, steel and wood will also shrink during the summer. This is seriously affecting my AirBike. The fuselage cockpit seems to be getting smaller, and the wings are getting shorter. The smaller fuselage is causing an ergonomic problem. The shorter wings result in less surface area and thus less lift causing my takeoff runs to be longer. At the current shrinkage rate, eventually I'll know there is really a problem when I get to the runway's end and still haven't lifted off!
However, there is one aspect of my shrinking AirBike that I have recently been able to compensate for. The control stick. As the plane shrunk, the control stick got closer to the seat which caused a decreased amount of aft stick movement! This is serious because it is more difficult to make a landing flare with only partial stick. I actually have to lean to one side to get the stick back far enough to touch down gently!
Perhaps some of you who have been flying the same plane for a number of years are experiencing a similar unique shrinking phenomenon? Fortunately, I have come up with a solution that you might want to utilize if you also have a shrinking plane.
My solution? I made an offset control stick to replace the original straight stick. Starting with a wooden model to verify the design intent, I then duplicated it in tubular steel. The photos and their titles serve as captions for the process. Recently, I installed the offset control stick and am pleased with its increased movement. I now have more elevator travel and am looking forward to its behavior when flying.
I sure hope this shrinking phenomenon doesn't affect the new stick, if it does, it could get so short that it loses effective leverage! My wife mentioned that my having gained 70# since building my AirBike in 1998 may have some effect. But then, what does she know about airplanes?
Paul Fiebich
Not having all the necessary manufacturing skills myself, I needed to rely on friends to do the welding and machining. Thanks Tom and Steve!
Sorry, the photos didn't come out in the order I had intended. The drawing is right out of the AirBike plans.
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flydog |
February 11, 2019, 7:22pm |
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Ace
Posts: 547
Time Online: 50 days 41 minutes
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tomshep |
February 11, 2019, 8:11pm |
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Ace
Posts: 446
Time Online: 28 days 19 hours 43 minutes
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Told you not to tumble dry it. I have the same problem but find the reach to the stick too far. Short arms, I guess. I am thinking of moving the stick back an inch. |
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Bob Hoskins |
February 11, 2019, 9:50pm |
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Fly Safe Ace
Posts: 1,208
Time Online: 38 days 16 hours 39 minutes
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Hey; You Guys are a HOOT, LOL. You know Paul, "where there is a will, there is a way". Great stuff. Bob |
| Fly safe and have fun. |
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fiebichpv |
February 12, 2019, 2:46pm |
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A/B Plans #112 has 1008 hours as of 02-09-2015 Ace
Posts: 1,694
Time Online: 36 days 13 hours 20 minutes
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Thanks for the reminder Ace, I did forget not to tumble dry it. Also I thought the plane was "Sanforized" (remember that term?) which it wasn't, hence it shrunk. Hey, I like the model plane, any idea who built it and where? Attached are some photos of an AirBike model a friend built, flew and then donated it to the Kansas Aviation Museum to be displayed in my classroom. I think this one must have been left out in the rain as it REALLY shrunk!!! Paul
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flydog |
February 12, 2019, 9:57pm |
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Ace
Posts: 547
Time Online: 50 days 41 minutes
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joe.scalet |
February 13, 2019, 12:48am |
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Flight Leader
Posts: 155
Time Online: 2 days 1 hours 58 minutes
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Paul: I have the a double problem, my stick did not have enough forward movement, my belly restricted up travel. I'm thinking adding canard surfaces (A La Long EZ) might be the way to go. |
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The Termite |
February 13, 2019, 10:49am |
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Ace
Posts: 588
Time Online: 5 days 3 hours 12 minutes
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Sounds like some of you guys have a "dickie-do" problem............... |
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PUFF |
February 13, 2019, 12:40pm |
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Ace
Posts: 1,518
Time Online: 34 days 6 hours 18 minutes
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