Trimmed out but doesn't look right?
07-24-2007 | 01:00 PM
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From: wichita,
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Trimmed out but doesn't look right?
Hey Guys, I just did my maiden flight with my H9 Solo Sport and got it all trimmed out and flying great. When I got her back to the pits to see what kind of adjustments to make I noticed my elevator was slightly down instead of level with the horizontal stab. Not by much but why wouldn't this be level? Since this is an ARF I figure maybe the wing incedence isn't right or the down thrust on the engine mount isn't right....I'm guessing here. I'm not even sure if it's worth messing with.....I did get her too fly straight and true. When I balanced her she had a slight nose down attitude.
07-24-2007 | 01:07 PM
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From: Poolesville, MD
RE: Trimmed out but doesn't look right?
If the trailing edge of the stab is slightly down, then the plane is a bit tail heavy still.
You are compensating for this by pushing the nose down with the trims.
You could fly it as is, or you could try adding more weight to the nose and re-trim.
If the variance is not that much, and you like how it flies, leave it as is.
You are compensating for this by pushing the nose down with the trims.
You could fly it as is, or you could try adding more weight to the nose and re-trim.
If the variance is not that much, and you like how it flies, leave it as is.
07-24-2007 | 01:11 PM
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From: Richmond,
TX
RE: Trimmed out but doesn't look right?
The elevator on my LT-40 is slightly down. I am sure it is because the wing on that plane creates so much lift that the plane always wants to climb, so you have to help push it back down with a bit of down elevator.
07-24-2007 | 01:36 PM
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RE: Trimmed out but doesn't look right?
ORIGINAL: ag4ever
The elevator on my LT-40 is slightly down. I am sure it is because the wing on that plane creates so much lift that the plane always wants to climb, so you have to help push it back down with a bit of down elevator.
The elevator on my LT-40 is slightly down. I am sure it is because the wing on that plane creates so much lift that the plane always wants to climb, so you have to help push it back down with a bit of down elevator.
I can remember back in the single channel days when we had to test glide our models for proper glide slope then adjust engine thrust to trim for full power flight.
Just thinking on the LT-40 with ailerons and a single servo - would it be beneficial to adjust the aileron horns to have slightly "up" aileron deflection on both sides? It seems if you adjusted them slightly down you'd effectively have permanent down flaps.
07-24-2007 | 01:42 PM
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From: Nutley,
NJ
RE: Trimmed out but doesn't look right?
WHERE ARE YOU WITH YOUR THROTTLE WHEN TRIMMING? IF YOU ARE AT FULL OR CLOSE TO IT...THE PLANE IS DESIGNED TO LIFT WHEN THROTTLE IS APPLIED. SHOULD BE TRIMMING AT COMFORTABLE CRUISE SPEED. WILL DIFFER DEPENDING ON SIZE OF ENGINE.
07-24-2007 | 02:34 PM
#7
RE: Trimmed out but doesn't look right?
ORIGINAL: PipeMajor
This may be typical of the LT-40s. Mine has about ¼" of down trim cranked into the elevator. I use a black foam "pad" for the wing seat so I'm sure that creates a slight reduction in wing positive incidence. My problem may be power - excess power. Even with the generous amount of built-in downthrust, my TT 46 Pro powered Kadet climbs with authority. I'll have to readjust the servo wheel to ensure I get an equal amount of up and down travel in an elevator that had previously been adjusted at 0º.
I can remember back in the single channel days when we had to test glide our models for proper glide slope then adjust engine thrust to trim for full power flight.
Just thinking on the LT-40 with ailerons and a single servo - would it be beneficial to adjust the aileron horns to have slightly "up" aileron deflection on both sides? It seems if you adjusted them slightly down you'd effectively have permanent down flaps.
ORIGINAL: ag4ever
The elevator on my LT-40 is slightly down. I am sure it is because the wing on that plane creates so much lift that the plane always wants to climb, so you have to help push it back down with a bit of down elevator.
The elevator on my LT-40 is slightly down. I am sure it is because the wing on that plane creates so much lift that the plane always wants to climb, so you have to help push it back down with a bit of down elevator.
I can remember back in the single channel days when we had to test glide our models for proper glide slope then adjust engine thrust to trim for full power flight.
Just thinking on the LT-40 with ailerons and a single servo - would it be beneficial to adjust the aileron horns to have slightly "up" aileron deflection on both sides? It seems if you adjusted them slightly down you'd effectively have permanent down flaps.
07-24-2007 | 03:18 PM
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From: Nutley,
NJ
RE: Trimmed out but doesn't look right?
ORIGINAL: acarter
well, my avistar has about 1/4" down elevator, my instructor said that it is because the wing produces so much lift
well, my avistar has about 1/4" down elevator, my instructor said that it is because the wing produces so much lift
07-24-2007 | 04:25 PM
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From: wichita,
KS
RE: Trimmed out but doesn't look right?
RO347, Never thought about the throttle causing that but I was at full throttle when I trimmed her out. I might add just a little more weight to the nose and see what happens if that helps, but it sure glided in smooth for the landing.... floated right down real pretty. I'm sure a little more to the nose won't hurt that too much.
07-24-2007 | 06:54 PM
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From: Poland,
OH
RE: Trimmed out but doesn't look right?
ORIGINAL: pywackit
RO347, Never thought about the throttle causing that but I was at full throttle when I trimmed her out. I might add just a little more weight to the nose and see what happens if that helps, but it sure glided in smooth for the landing.... floated right down real pretty. I'm sure a little more to the nose won't hurt that too much.
RO347, Never thought about the throttle causing that but I was at full throttle when I trimmed her out. I might add just a little more weight to the nose and see what happens if that helps, but it sure glided in smooth for the landing.... floated right down real pretty. I'm sure a little more to the nose won't hurt that too much.
07-24-2007 | 08:15 PM
#13
RE: Trimmed out but doesn't look right?
I have an old Hangar 9 Easy Fly 40 ARF that I'd been flying up until this spring. The wing sits crooked in the wing saddle, the verticle and horizontal stabilizers are all crooked, and the landing gear is bent up. Nothing on that plane looked like it was supposed to. It sure flew great though.
I replaced it with a new Tower Trainer .40 MkII ARF this spring, however, because I just couldn't stand to look at it any more.
Generally speaking, however, if the plane flies straight, that's much more important than if it looks like it flies straight.
I replaced it with a new Tower Trainer .40 MkII ARF this spring, however, because I just couldn't stand to look at it any more.
Generally speaking, however, if the plane flies straight, that's much more important than if it looks like it flies straight.
07-24-2007 | 08:36 PM
#14
RE: Trimmed out but doesn't look right?
Typically when flying aircraft the only time you are fire walled (full throttle) is on takeoff. Once you have climbed to altitude throttle back to cruise setting, after you are at a good cruise 1/2-5/8 power trim for level flight. Now is you add power you climb, reduce power you descend. You use throttle setting, not elevator to climb and descend your elevator is pitch control not the up down control.
07-24-2007 | 08:48 PM
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From: schuylkill haven, PA
RE: Trimmed out but doesn't look right?
ORIGINAL: ro347
1/4"?
ORIGINAL: acarter
well, my avistar has about 1/4" down elevator, my instructor said that it is because the wing produces so much lift
well, my avistar has about 1/4" down elevator, my instructor said that it is because the wing produces so much lift
07-24-2007 | 09:41 PM
#16
RE: Trimmed out but doesn't look right?
At full throttle your plane should climb. You should trim for straight and level flight at about 1/2 throttle. You should be able to control a climb or decent with throttle alone. A basic flight principal is that the primary control of altitude is by throttle and the primary control of speed is pitch. They are closely related and in RC are often interchanged. Think of the throttle almost like a trim. It is properly set for neutral at 1/2 throttle. A properly ballanced and powered plane should fly straight and level when all surfaces, including throttle are in thier neutral/midpoint settings.
Scott
Scott
07-24-2007 | 09:51 PM
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From: wichita,
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RE: Trimmed out but doesn't look right?
Iron Eagle......"Now as you add power you climb, reduce power you descend. You use throttle setting, not elevator to climb and descend, your elevator is pitch control not the up down control."
This is the first time I've ever heard this, so I just need to back off from full bore and trim her out at cruise speed....well this makes perfect since! I'm guessing that everything is fine then.....all good news and flying tips too.... [&:]
Thanks guys! Glad I asked....
This is the first time I've ever heard this, so I just need to back off from full bore and trim her out at cruise speed....well this makes perfect since! I'm guessing that everything is fine then.....all good news and flying tips too.... [&:]
Thanks guys! Glad I asked....
07-24-2007 | 09:57 PM
#18
RE: Trimmed out but doesn't look right?
One of the most important things you will learn in flying is throttle management, this applies both to R/C and full scale.
Once you lean that the left stick is more than an on off switch for the motor, you will get more flying time, extend the life of your engines, and reduce the strain on your airframe.
Now that not to say that blasting around one in awhile is not fun....
Once you lean that the left stick is more than an on off switch for the motor, you will get more flying time, extend the life of your engines, and reduce the strain on your airframe.
Now that not to say that blasting around one in awhile is not fun....
