polaris330

I am new to electric and trying to tune or trim my plane. The symptom I have is that after eassh maneuver the plan tends to zoom up and I need to give down elivatoer to prevent a stall. This seems to happen at most any throttle level. Can you suggest a solution?

cyclops2

What is the manufacturers name of the plane?

3 common causes of any plane zooming up with flying speeds are.

1 The wing is angled up too much.

2 The rear elevator surfaces are angled down too much. Could be either the part that does not move or the movable surface.

1 and 2 are correct if you can toss the plane and it does a fast, steady, gradual glide to the ground at least 30' away.

When you get a good glide, then any UP or DOWN zooms are being caused by the motor being angled up or down incorrectly.

Plane climbs with lots of power, angle the motor down.

Remember, ALL planes have a unexpected loss of power some day.

The plane MUST glide beautifully or it crashes.

polaris330

The plane is a Super Impress II . The plane glides well and climbs without power stalling with neutral control. What seems to happen is that at the end of a turn or a loop the plane ends with a climb and near stall, needing some down elevator. Power off glide is nice. I suspect CG is off or incidence but not sure which and in which direction.

Thanks for any help you can provide.

Doug

Matt Kirsch

My Feedback: (21)

Doug,

Perhaps the problem is more esoteric in nature (is that the right word?). Anyway, what I mean is that the plane could be zooming up after maneuvers because you're unconsciously holding up elevator at the end of the maneuver. As an instructor in my club, I see this quite frequently. It's a matter of breaking a bad habit before it forms.

lwatson

My Feedback: (2)

I disagree, the plane zooms up because it has too high of incidence. It is esentially flying in a mild stall all the time. After a move, say a right turn, you loose lift, the plane speeds up, once it is corrected the higher speed causes the ballooning effect.

This is symptimatic of an underpowered plane. You would not need the high incidence in the wing if the engine could pull it a little quicker. So you have a couple options:

1) Change to a little larger or smaller prop and see if you can get more power. (see * below)
2) Put in a larger battery and lower the incidence.
3) Put in a 2 cell lipo, lower the incidence and get some real zip.
4) Or do nothing.


Option 4 is actually a good one, If you can learn to fly this in this condition, it will make flying your next plane easier. If however, the plane will fly at 3/4 engine power, you are not underpowered and you should just decrease the incidence. (shim the wing)



* each motor, battery and gear, combination has an optimal prop that will generate the most thrust without over stressing the battery or motor. If you overprop you will loose power and generate heat, if you underprop you will not transfer the available energy to the air.

Fliprob17

The motor shaft may also be slightly angled up, had this happen on one of my planes. Did the same exact thing, flew fine, but after loops and barrel rolls always wanted to go up.

jcflysrc

My Feedback: (50)

Check the thrust angle . The motor shaft should be pointing slightly to the right, and slightly down. This should get you close. Balance at the CG the manufacturer recommends.

After trimming the plane, it should fly level at variuos throttle settings. It should roll straight, and climb straight. It should fly inverted with no, or very little pressure on the stick. I think flying cirkus has a video on trimming you should check out.

[link]Http://www.teamflyingcirkus.com/newindex.php?page=videos[/link]