flutter problem
 

Ive got an Alpha 40 with a 46 OS. At WOT ,all the control surfaces flutter back an forth slightly,,If I drop the idle to 1/2 and below the fluttering stops. All new JR standard servos,,with new JR receiver. engine run smoothno vibrartionsDrives me crazy! any ideas anyone?


Thx TAZZZZ[sm=angry_smile.gif]

RE: flutter problem
 

It's not too unusual to see some movement of control surfaces with a model on the ground with the engine flat out. However smooth you think your engine may be it is unlikely that a single cylinder engine would not generate some vibration.

Provided what you are seeing is SLIGHT movement it really doesn't seem that you have anything to worry about, the movement being caused by mechanical means rather than radio interference.

Terry

RE: flutter problem
 

I think Terry nailed that one. A bit of control bounce when on the ground is normal and nothing to worry about. When we speak of flutter it is during flight and usually at high speed. The controls move a lot, you can hear and see them and it is enough to strip the gears of the servos.

RE: flutter problem
 

I don't think you have flutter...flutter happens in flight and makes a buzzing sound followed shortly there after by a big ball of confetti in the sky or a smoking hole in the ground

RE: flutter problem
 

;)
First pin point what the flutter/vibration problem is coming from,, is it the servos moving or just the control surfaces flexing a little.

Have some one hold the plane at WOT and feel if in fact the servos are moving, if the servos are glitching you have a problem, if not then it does sound like just a little normal balsa flexibility

RE: flutter problem
 

I dont know about the control surfaces,,but I can see the throttle linkage moving back and forth,,,,,,,none of my other planes do this,,thats what I cant figure out.

TAZZZZ

RE: flutter problem
 

Ive seen something like this before. all surfaces were glitching at full throttle, turned out that the receiver was at fault under vibration. Now when I do a range check I also check it at different throttle settings.

RE: flutter problem
 

Unfortunately you'll have to isolate one component at a time, could be the Receiver, a servo, a switch, battery lead, servo extension,,, metal to metal contact somewhere?

I'd start by unplugging or replace each component first with switching out the Receiver, it it's not that then one servo at a time, plug the battery directly into the Rx to see if it's the switch, etc.

good luck

RE: flutter problem
 

I was going through this not long ago on one plane. Then things started going wrong with another. It finally showed itself to be my radio and it just got sent in for service. Finding glitch problems can often be a long drawn out problem. In my case it manifested itself slowly from plane to plane.[>:]

RE: flutter problem
 

Yeah,, I had some weird glitching problems once, finally traced it to the transmitter's antenna wire screw not being tight, this could have been real bad.., never rule out the TX either.

RE: flutter problem
 

You didn't say what transmitter and what receiver you have ????

One thing you should do is to try moving the plane and radio to different places to see if it still glitches. Some times you can get deflection off something that will do that, having the plane sitting close to cars or something is a good possibility. ENJOY !!! RED

RE: flutter problem
 

The same thing happened to me about 4 years ago with my Hanger 9 Fokker DVII. If you are using digital servo's, it is normal to have them bounce around because they are always trying to find dead center electronicly.

When it happened to me, I noticed that my Y-harness was pinched between the back part of the glow tank and a wooden truss I had putting pressure on the tank to keep it forward. Every time I throttled up, the servo's went crazy, then when I throttled down about half throttle it'd stop. It drove me crazy! I knew the vibration was causing problem, but I didn't have a clue!


Once I found the culprit of the problem, I changed the Y-harness with a brand new one and made sure none of my wires were pinched. I've been flying the same plane for 4 years now with no problems. I also check the balance on my prop to lesson the vibration.

Hope I helped,


Pete

RE: flutter problem
 

My bet is on the reciever. I owned one jr reciever and after swapping it out all problem solved.

RE: flutter problem
 

I've not ever had a problem with JR at all, that's because I don't fly 2.4. My 72MHz equipment is almost 10 years old and works as good the day I bought it. I haven't had to replace my TX or RX, for them to go bad is very rare from what I know in my years of being in this hobby.

Hopefully he'll write back and tell us what the problem was and I'll stand corrected if I am wrong.


Pete

RE: flutter problem
 

You really hate 2.4 don't you lol..

RE: flutter problem
 

Emotions have nothing to do with it.


Pete