Rowland,
Not being the designer of the aircraft it's hard to provide a definite opinion
about tolerance on the balance. But I can provide you my experience with 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 newsletters
that this is a common problem with the LongEZ and Rutan adamantly 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 combined with a little
wear in the hinge and a natural frequency that will cause the vibration.
So to the relevant part to your issue. The LongEZ elevator balance could flutter
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 attached to.
The canard flexes a lot so flutter will bend the canard and will 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 LongEZ, don't know about
the Europa.
When I pulled my aileron out and I checked the balance, it was TE down by quite
a bit. But the aircraft flew for 20 years like that and it was even used 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 the LEZ is further
forward
---From the hinge line than in the Europa. Once you find a satisfactory number
of layers, you go fly and if you are happy you scuff 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 balance
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 sanding of the
aileron
bottom, you need to check at your end. But what I am trying to say, is don't
sweat it. If the aileron is a bit heavy (but balanced) the airplane is going
to fly great anyway!
However, I concur with the other forum member. Do question the weight of the
paint
now that you have time. It maybe OK but get some feedback and see if yours
is coming up too heavy.
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