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Problem with Kwik Fly 60

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zoid

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Oct 31, 1999, 2:00:00 AM10/31/99
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I have a Global Hobbies Kwik Fly 60 that I recently finished building. It is an ARF, and called a "low wing trainer", presumably due to the slight amount of dihedral in the main wing. Overall, it looks a lot like a Kaos. I have 7 flights on it in three days flying, but I am having a lot of trouble trimming it out.
 
As soon as I get up to speed and lift off the runway it wants to go straight up. I then put full down elevator trim in it, but it makes little difference, It wants to go straight up. Even when I throttle back, it still fights me to continue climbing. I have:
 
1. Tried additional down thrust (on the advice from the RC field) - no help.
2. Tried additional up thrust (as the kit instructions say) - no help.
3. Checked the ailerons for proper incidence - no help.
4. Increased the incidence in both ailerons to assure they are not acting as flaps - no help.
 
The plane is not overpowered and the only thing left is to build in a ton of down elevator mechanically, and set the radio trims at neutral. But that just doesn't seem right.
 
Does anyone have experience with this plane or have solutions to this problem. This plane is unflyable the way it is and I'm out of ideas. Thanks.

zoid

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Oct 31, 1999, 2:00:00 AM10/31/99
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Checked the CG as well. It is right on according to the instruction manual.
gareth bannister wrote in message ...
did you check the CG yet?   it sounds like you need some weight up front.

Todd

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Oct 31, 1999, 2:00:00 AM10/31/99
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Sounds tail heavy to me.

gareth bannister

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Nov 1, 1999, 3:00:00 AM11/1/99
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did you check the CG yet?   it sounds like you need some weight up front.

Edwin Smith

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Nov 1, 1999, 3:00:00 AM11/1/99
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At this point I would check the incedence on stab, wing and engine and at least try to get it to 0, 0, 0, dont forget engine side thrust.  Then start adjusting per the instructions from there.  BUT, it sounds like you might just want to toss the instructions though.  Had a scratch built that did something similar many years ago.  Turned out to be +2 deg incedence in the wing AND the engine.   I like to use bubble and 6" pocket levels to set up my reference. 
   You can make an incedence meter by glueing a protractor to some round or square brass tubing (it will hang down).  Get the next size smaller tube to make it telescoping.  Then make some V notches in wood or something that come down equa-distant on both ends, about 4 to 6" or so.  For the marker, stick a quick link in the hole at the center of the protractor and use 1/16" wire, let it swing freely hanging down.  Make sure the protractor is glued hanging down.  I put a rubber band around the whole contraption to keep it together.  Should be able to make one for about $5.
Edwin
zoid wrote in message <5S8T3.7$F3.170...@news.frii.net>...

Bernard Grosperrin

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Nov 2, 1999, 3:00:00 AM11/2/99
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makes a much sense as "seems blue to me"
 
OK, I don't know this specific airplane, but if you have checked that the CG is as per the instructions, I would check the relative incidence between the tailplane and the wing. Should not be much more than 1 or 2 degrees, maybe 0. Maybe you get a lot of positive incidence on the wing ( trailing edge lower than leading edge ), for whatever reason, and that would make your plane wanting to climb always, or you have a lot of negative incidence on the tailplane ( leading edge lower than trailoing edge ),but the end result ( angle between the twos ), is the same: too much angle....
 
BTW, this plane is maybe not totally neutral, and climbing at full power could be a desired "feature"....
 
If this diagnostic has something to do with reality, it would be normal that increasing downthrust does not solve the problem, as well as down elevator, which effect will change with speed....
 

--
Bernard Grosperrin
"Bernie"
Team Topspeed
http://www.cwsuperpage.com/bernie
 
PS- The proper incidence angle between wings and tailplane depend of the CG, so be sure it's correct first.
Sounds tail heavy to me.

Ken

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Nov 3, 1999, 3:00:00 AM11/3/99
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Sounds like it is tail heavy to me.

--
"Only The Good Parts Of Time Fly By" ken"

Visit My RC Web Site http://home.rochester.rr.com/sar/

Bill Ellis

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Nov 4, 1999, 3:00:00 AM11/4/99
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zoid wrote:
 I have a Global Hobbies Kwik Fly 60 that I recently finished building. It is an ARF, and called a "low wing trainer", presumably due to the slight amount of dihedral in the main wing. Overall, it looks a lot like a Kaos. I have 7 flights on it in three days flying, but I am having a lot of trouble trimming it out. As soon as I get up to speed and lift off the runway it wants to go straight up. I then put full down elevator trim in it, but it makes little difference, It wants to go straight up. Even when I throttle back, it still fights me to continue climbing. I have: 1. Tried additional down thrust (on the advice from the RC field) - no help.2. Tried additional up thrust (as the kit instructions say) - no help.3. Checked the ailerons for proper incidence - no help.4. Increased the incidence in both ailerons to assure they are not acting as flaps - no help. The plane is not overpowered and the only thing left is to build in a ton of down elevator mechanically, and set the radio trims at neutral. But that just doesn't seem right. Does anyone have experience with this plane or have solutions to this problem. This plane is unflyable the way it is and I'm out of ideas. Thanks.


I just finished but have not flown the Kwik Fly 60.  At the field today I chatted with a fellow flying this same plane and he complained of the same problem that you are having..   He pointed out a very significant amount of down elevator trim he had introduced into his plane to keep it level in flight.. He had no solutions.  

If you come up with an answer to this problem,  I would appreciate an email..  Ill keep an eye on the responses you get on the newsnet and let you know what happens when I fly mine on Saturday.

Thanks

Bill Ellis

RCKRZY1

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Nov 4, 1999, 3:00:00 AM11/4/99
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In article <3820F36E...@mediaone.net>, Bill Ellis <bel...@mediaone.net>
writes:

>
>If you come up with an answer to this problem, I would appreciate an
>email.. Ill keep an eye on the responses you get on the newsnet and let
>you know what happens when I fly mine on Saturday.
>
>Thanks
>
>Bill Ellis

My 40 size quick suffers a near same problem, it climbs in direct proportion
to speed, I need to mix down ele with throttle, it is not a good design in
my opinion, I got it thinking it was a clone of the old royal arf kit the 40L,
which did not suffer the same.

Adam Tucker
AMA 520901
Hurst Tx

Remove "NOcrap" to Reply by Email

mkir...@rochester.rr.com

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Nov 4, 1999, 3:00:00 AM11/4/99
to bel...@mediaone.net

> I just finished but have not flown the Kwik Fly 60. At the field
today
> I chatted with a fellow flying this same plane and he complained of
the
> same problem that you are having.. He pointed out a very significant
> amount of down elevator trim he had introduced into his plane to keep
it
> level in flight.. He had no solutions.

There are two solutions:
1. The specified CG is wrong, and the plane is tail heavy. One of the
most common "service bulletins" that comes with kits/ARFs are ones
telling you the CG in the instructions is wrong. However, you would also
notice stability problems (a tendency to snap roll possibly, very touchy
on the elevator).
2. The most likely candidate is an incidence problem. Like what has been
rehashed many times in this thread, the horizontal stab may have too
much negative incidence, and/or the wing may have too much positive
incidence. Hopefully it's the wing, because in that case all you need to
do is sand down the rear of the wing saddle slightly and recheck.
Cutting the stab out if it's wrong is a major chore.

Borrow an incidence meter and check it out.

> If you come up with an answer to this problem, I would appreciate an
> email.. Ill keep an eye on the responses you get on the newsnet and
let
> you know what happens when I fly mine on Saturday.

Sent via Deja.com http://www.deja.com/
Before you buy.

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