Weird H9 Funtana problem
#27

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From: Ingleside,
TX
Are you using a PCM heli radio and an FM receiver? I have a Futaba 9CHP, and if I switch on the radio without setting the transmitter for FM, then I will get flutter.
Joe
Joe
#28
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From: Canterbury Kent, UNITED KINGDOM
Bruce.
Sorry for lack of reply, been offline for a while. It would appear that something (servo leads?) is picking up co-channel or other airborn interference at the field. You would not get this at home. Have you got any Ferrite Rings (like the glider boys use on long leads in wings etc ?)
Twisting the leads may help, but Ferrites might give better results if this is the problem.
Have you had any joy with your investigations?
Ian.
Sorry for lack of reply, been offline for a while. It would appear that something (servo leads?) is picking up co-channel or other airborn interference at the field. You would not get this at home. Have you got any Ferrite Rings (like the glider boys use on long leads in wings etc ?)
Twisting the leads may help, but Ferrites might give better results if this is the problem.
Have you had any joy with your investigations?
Ian.
#29
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From: London, US MINOR OUTLYING ISLANDS
I havn't read all of the posts but how about checking your battery operating temparature. Or Transmitter battery.
I agree with tipstall about the heli transmitter but its just a thought.
I agree with tipstall about the heli transmitter but its just a thought.
#30
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From: Auburn, AL
I don't think anyone mentioned this exact solution. As for why this would only be an issue at the field and not home, I don't know, mabye just a few more frequencies to finish the deal. You mentioned that this happened when you plugged in an aileron or elevator servo. That right there helps narrow down the problem. I believe you already tried new servo's on that, but if not, see if that helps. However, if I understand right both of these are on servo extensions. It isn't voltage that is a problem with extensions, but the signal, in the yellow/orange wire that is the problem. Get some HD servo extensions WITH an amplifier. What it does is take the semi-weak signal about half way down the wire, amplifies it like it just came out of the reciever, and sends it to the servo. They are a little more expensive, but on any servo extensions thats what I use. Good Luck
Alex
Alex
#31
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From: Arcadia,
CA
Hi all,
First let me say a huge THANK YOU to everyone for your help. You have all been extremely helpful.[sm=thumbup.gif]
I did several things to the plane this week. I moved the battery pack and receiver further back which enabled me to install two shorter extensions on the rudder and elevator servos. I moved shortened the throttle pushrod as there was a 1/2" overhang near the throttle servo lead so I wanted to make sure that was not aggravating the situation. I did some more research and found that we have cell phone tower nearby the field which may or may not account for the fact that this interference is happening at the field and not at home.
I went to the field this morning and tried the plane and although the flutter was not so bad, there was still flutter there. So I finally did the twist thing, not so much as a last resort, as that I wanted to isolate whether this actually fixed the problem.
Guess what???!!! It did. After twisting aileron, rudder and elevator servo extensions in a reasonably tight twist, none of them ore even buzzing. So I guess the twist thing did it.
A friend of mine (one of the instructors at the field the guy who solo'd me) is an electrical engineer and he explained why this works. It makes sense. He also explained that the cell phone tower may actually affect the signal on the lines between the receiver and the servo and that this could explain the problem.
Anyway, my plane can now fly!!!![sm=biggrin.gif][sm=biggrin.gif][sm=biggrin.gif]. Tomorrow I'll be getting the chief instructor to take it up (it's a policy we have at the field) and hopefully the plane will fly like a dream.
Thank you all for your help. You guys have been terrific.
regards,
Bruce
First let me say a huge THANK YOU to everyone for your help. You have all been extremely helpful.[sm=thumbup.gif]
I did several things to the plane this week. I moved the battery pack and receiver further back which enabled me to install two shorter extensions on the rudder and elevator servos. I moved shortened the throttle pushrod as there was a 1/2" overhang near the throttle servo lead so I wanted to make sure that was not aggravating the situation. I did some more research and found that we have cell phone tower nearby the field which may or may not account for the fact that this interference is happening at the field and not at home.
I went to the field this morning and tried the plane and although the flutter was not so bad, there was still flutter there. So I finally did the twist thing, not so much as a last resort, as that I wanted to isolate whether this actually fixed the problem.
Guess what???!!! It did. After twisting aileron, rudder and elevator servo extensions in a reasonably tight twist, none of them ore even buzzing. So I guess the twist thing did it.
A friend of mine (one of the instructors at the field the guy who solo'd me) is an electrical engineer and he explained why this works. It makes sense. He also explained that the cell phone tower may actually affect the signal on the lines between the receiver and the servo and that this could explain the problem.
Anyway, my plane can now fly!!!![sm=biggrin.gif][sm=biggrin.gif][sm=biggrin.gif]. Tomorrow I'll be getting the chief instructor to take it up (it's a policy we have at the field) and hopefully the plane will fly like a dream.
Thank you all for your help. You guys have been terrific.
regards,
Bruce
#32
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From: Curitiba, PR, BRAZIL
I had this on my FunFly too with Hobbico CS-60 servos all around. When I turned the Rx, the ailerons would flutter like crazy. I pinned the cause to overtighting the screw that holds the servo arm. Loosend it 1/4 turn and problem solved. Maybe this is what's happeneing with yours.
BTW, why it only happens at the field is really a mistery.....
Maybe your house is isolated from outisde interference and the field is not??
BTW, why it only happens at the field is really a mistery.....
Maybe your house is isolated from outisde interference and the field is not??

#35
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From: Arcadia,
CA
Hi all,
Just a further update on this...
I got to the field this morning, gassed her up and gave her to the chief instructor. He took her up, trimmed her out, and reckoned she behaved like an absolute angel. I got to fly her for a while, although I was a little nervous as the wind was gusting 10-15 mph. She's had her maiden flight and she flew really nicely.
Again, thank you all for your help.
regards,
Bruce.
Just a further update on this...
I got to the field this morning, gassed her up and gave her to the chief instructor. He took her up, trimmed her out, and reckoned she behaved like an absolute angel. I got to fly her for a while, although I was a little nervous as the wind was gusting 10-15 mph. She's had her maiden flight and she flew really nicely.
Again, thank you all for your help.
regards,
Bruce.



