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Ultimate Trimming problem

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Ultimate Trimming problem

Old 04-03-2007, 04:04 AM
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hendrix6969
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Default Ultimate Trimming problem

Please help.. I have built a seagull ultimate 60 size biplane. I have installed a ASP 180 2 stroke moter the plane is balanced C.G perfect Lateral balance on the ground is fine.
1. the problem is that on low rates 40% on elevater the plane snaps out at top of loops.. help
2. fly vertical and the plane tends to lean to the left like useing rudder but the rudder is straight?..help
3. to get plane to fly straight i need to use like 10 clicks of left aliron trim.. help
any ideas would be very helpfull also i had trided the same settings with a 120 4 stroke and the same problems werer there as well. the plane flew underpowered with the 4 stroke.
all control serfaces seem to be straight and in good shape.. i have never had this problems with any other model?
Old 04-03-2007, 05:01 AM
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Ed_Moorman
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Default RE: Ultimate Trimming problem

1. When a plane snaps out of loops, it is usually an indication that you have too much elevator or are flying too slowly for the weight of the plane. I'd say to reduce the elevator movement.

2. It is normal for torque to pull the plane to the left in vertical climbs. It is most noticeable when the plane slows down. You'll need right rudder or right thrust.

3. You may have a little twist in one of the wings. Stand out in front of the plane and look directly across the wing. You may be able to notice one trailing edge is higher than the other. With a bipe, you may need to shim the N-strut connection on one side or the other to get the warp out of the wing.

4. I would also seal the aileron-wing gaps.
Old 04-03-2007, 07:34 AM
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MinnFlyer
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Default RE: Ultimate Trimming problem

60 size plane, 180 engine

And you wonder why it pulls to the left???

There's this thing called torque.
Old 04-03-2007, 09:42 AM
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daveopam
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Default RE: Ultimate Trimming problem

I thought the same thing Minn. I'll bet it's a typo and he meant 1.08.

David
Old 04-03-2007, 09:48 AM
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MinnFlyer
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Default RE: Ultimate Trimming problem

Similar problem.

A bipe has a shorter wingspan than a monoplane and is therefore more susceptible to torque.
Old 04-03-2007, 06:08 PM
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Default RE: Ultimate Trimming problem

But wouldn't you like to get on the sticks for a while. I'll bet it has some kind of climb.
Old 04-03-2007, 06:14 PM
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Default RE: Ultimate Trimming problem

Old 04-04-2007, 12:49 AM
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hendrix6969
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Default RE: Ultimate Trimming problem

there is no typo it is a 180 2 stroke ASP glow moter
yes it flys the plane with unlimited vertical climb
the fuzz is build fatter and stronger than the great planes bipe.. alone the plane with no moter servos etc has a weight of 4.2klgs
I have tested the plane at the feild this morning and have discovered that the right servo pushing one of the elevators is not moving the same as the left one but this is so hard to see with the eyes and took a bit of time to accually see the problem so i go and get some JR 539 servos and try again the servos in the plane now are futarba s3003's so the only thing i can think of is that they are not a matced pair.. thanks for all of your help guys and i will let you know how the new servos go and will post a pic or two of my bipe..

A bad landing requires a large box followed by a sore back.... happy flying..

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