Need help Aileron flutter
10-22-2009 | 09:50 PM
#26
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From: Littleton, CO
RE: Need help Aileron flutter
I had an Eratix 3D, and yes, mine had flutter when flown too fast. Unfortunately, it's the design of the airfoil. It has a very thick wing, and the Aileron is very large, and they're the same thickness from l/e to t/e.
Just to clear things up, it's not a small plane, it's a 54" w/s, and weighs in around 4 lbs. it's not a park flyer sized plane. It is, however, designed for 3D type aerobatics, not for speed. The thick airfoil allows the plane to almost float, and it is very capable when flown within it's design limits. Almost everyone I know that has this plane has experienced flutter when trying to fly it fast, mine would sometimes flutter when throttling up hard, even when the plane wasn't moving very fast.
The hardware that comes with the plane is actually pretty good, however there does seem to be just a slight bit of slop in the controls.
There's a whole thread dedicated to this plane in the Electric aerobatic forum, some very good reading pertaining to this plane.
Just to clear things up, it's not a small plane, it's a 54" w/s, and weighs in around 4 lbs. it's not a park flyer sized plane. It is, however, designed for 3D type aerobatics, not for speed. The thick airfoil allows the plane to almost float, and it is very capable when flown within it's design limits. Almost everyone I know that has this plane has experienced flutter when trying to fly it fast, mine would sometimes flutter when throttling up hard, even when the plane wasn't moving very fast.
The hardware that comes with the plane is actually pretty good, however there does seem to be just a slight bit of slop in the controls.
There's a whole thread dedicated to this plane in the Electric aerobatic forum, some very good reading pertaining to this plane.
10-22-2009 | 10:54 PM
#27
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RE: Need help Aileron flutter
ORIGINAL: speedy72vega
Almost everyone I know that has this plane has experienced flutter when trying to fly it fast, mine would sometimes flutter when throttling up hard, even when the plane wasn't moving very fast.
Almost everyone I know that has this plane has experienced flutter when trying to fly it fast, mine would sometimes flutter when throttling up hard, even when the plane wasn't moving very fast.
If you want to live with that then fine but if you prefer to not have the problem then reread Posts: #4, 9, 14 and #23 from j14152.
It works every time. The only people who say it has no effect are those who have never actually tried it. Its as simple as that.
John
10-26-2009 | 12:09 PM
#29
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From: Poolesville, MD
RE: Need help Aileron flutter
ORIGINAL: opjose
True, but this is VERY RARELY the cause of flutter on these small 3D planes the OP is talking about.
True, but this is VERY RARELY the cause of flutter on these small 3D planes the OP is talking about.
ORIGINAL: psuguru
Oh no it isn't
Oh no it isn't
ORIGINAL: opjose
Oh YES it is.
Oh YES it is.
ORIGINAL: opjose
And even then if this does occur a better fix is to re-inforce the flexy area with an inbedded CF rod or other similiar technique, that is actually effective.
And even then if this does occur a better fix is to re-inforce the flexy area with an inbedded CF rod or other similiar technique, that is actually effective.
ORIGINAL: psuguru
Better than eliminating the cause of the flutter?
You're writing rubbish man.
Better than eliminating the cause of the flutter?
You're writing rubbish man.
ORIGINAL: opjose
Slowing the plane down is the best fix.
In lieu of that what I wrote is applicable.
I would suggest you experiment to see before causing others to put planes in the trash bin.
Slowing the plane down is the best fix.
In lieu of that what I wrote is applicable.
I would suggest you experiment to see before causing others to put planes in the trash bin.
10-26-2009 | 12:47 PM
#30
Senior Member
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RE: Need help Aileron flutter
Some planes have a snare drum sound from the covering that isn't flutter, just noise. Flying slow with a 3 or 4 pitch prop is the wisest advice.
I would be leery of HS225s to handle too much abuse on a 3D plane, but I'm not "in the 3D loop" to know for sure.
I would be leery of HS225s to handle too much abuse on a 3D plane, but I'm not "in the 3D loop" to know for sure.
10-26-2009 | 01:15 PM
#31
RE: Need help Aileron flutter
Hi!
Your model is a 3-D model and as such isn't supposed to fly fast...But...If you want to reduce the change of getting flutter you do the following.
1. Get all linkages as tight as possible!
2. Use as long control arms (those at the elevator, rudder etc) as possible.
3. Use a short servo arms as possible.
4. Never let the ailerons get so long so they reach out to the wing tips. Stop 10-15cm from the wing tips!!!
5. Build the ailerons stiff!
6. Keep the gap between the flying surfaces tight (less than 0,5mm)!
6. Seal the gap between the flying surfaces with a strip of Oracover plastic film (best plastic film covering).
No mass balancing is necessary if the above advice is followed.
Your model is a 3-D model and as such isn't supposed to fly fast...But...If you want to reduce the change of getting flutter you do the following.
1. Get all linkages as tight as possible!
2. Use as long control arms (those at the elevator, rudder etc) as possible.
3. Use a short servo arms as possible.
4. Never let the ailerons get so long so they reach out to the wing tips. Stop 10-15cm from the wing tips!!!
5. Build the ailerons stiff!
6. Keep the gap between the flying surfaces tight (less than 0,5mm)!
6. Seal the gap between the flying surfaces with a strip of Oracover plastic film (best plastic film covering).
No mass balancing is necessary if the above advice is followed.
