Jan & RowlandI had a Long EZ too. Another cure for the aileron buzz was Fle
ttner stripssimilar to those on the Europa elevator trim tab. A sharp trail
ing edge is
emotionally satisfying but is not as efficient as we expect because of the
thickness of the boundary layer. That's why Flettner strips were added on t
he Europa.Graham
On Wednesday, 30 August 2017, 11:33, n7188u <chmgarb@gmail.com> wrote:
Rowland,
Not being the designer of the aircraft it's hard to provide a definite opin
ion about tolerance on the balance. But I can provide you my experience wit
h the LongEZ and an opinion of what I'd do.
My LongEZ developed a well known issue where the ailerons would have a high
frequency buzz when in cruise. Upon research, it is written in the Rutan n
ewsletters that this is a common problem with the LongEZ and Rutan adamantl
y claims it's not flutter (he says if it was flutter you wouldn't be there
to tell the story). What the issue is is an effect of engine vibration comb
ined with a little wear in the hinge and a natural frequency that will caus
e the vibration.
So to the relevant part to your issue. The LongEZ elevator balance could fl
utter if a little off balance and it is critical. But the aileron is not so
critical. The difference is the aeroelastic characteristic of what it is a
ttached to. The canard flexes a lot so flutter will bend the canard and wil
l worsen the flutter to the point of destruction. The wing is too stiff and
will hold things in check. If the elevator wont balance you have to throw
it away and make a new one. Not so with the ailerons. Again, this is the Lo
ngEZ, don't know about the Europa.
When I pulled my aileron out and I checked the balance, it was TE down by q
uite a bit. But the aircraft flew for 20 years like that and it was even us
ed for racing with no issues. Anyway, he procedure to fix the buzz is to ad
teflon liners to the hinge pins to eliminate slop and use a thin lead tape
(not the thick wheel balancing stuff) and layer it on the aileron LE nose
until the aileron is level. Keep in mind that the nose of the aileron on th
e LEZ is further forward from the hinge line than in the Europa. Once you f
ind a satisfactory number of layers, you go fly and if you are happy you sc
uff the paint fore and aft of the lead tape and place a 1 BID layer to make
it permanent (which I haven't done yet). Buzz is now gone.
So to your issue (my opinion): You can either place some tape on the balanc
e horns (sides or bottom) or sand some paint off the bottom of the aileron
and go fly. Building is fun but flying is more so :). Anyway, you will have
time to address what to do with it later but I suspect you will be having
too much fun flying! BTW, you being in the UK your only option maybe the sa
nding of the aileron bottom, you need to check at your end. But what I am t
rying to say, is don't sweat it. If the aileron is a bit heavy (but balance
d) the airplane is going to fly great anyway!
However, I concur with the other forum member. Do question the weight of th
e paint now that you have time. It maybe OK but get some feedback and see i
f yours is coming up too heavy.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=472349#472349
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