E-Impact Update

[Jim_Woodward at beaerospace.com]

Hi All,

I now have 6 flights on the Impact.  Not a hint of a problem yet.  I've 
tamed the "kick" of the Hacker by using a simple procedure.  Once plugged 
in, I raise the left slider (now slaved as throttle trim) so that the 
engine starts turning over in the 300 rpm range (which has no, to just a 
very small kick), then raise the throttle to full throttle, then down to 
idle.  With the Acro 90 set, I then reset the idle rpm for around the 300 
rpm range, and fly.  The idle stays through out flight.  Also, Acro 90 is 
set with the "exponential" curve in the controller, and I've adjusted the 
transmitters (9WCII) to somewhat of a reverse expo, and the feel is really 
nice like this.  Small reductions from full throttle are noticable, and 
the baseline stuff is at a nice (slow to medium) speed.  The small 
reduction from full throttle having good resolution is important, because 
you do not need full throttle to fly P05 (only after the upline snap). 

The power side of the equation is close to "set", however, the Impact has 
some interesting characteristics to get use to.  The timing on snaps and 
spins is different than I am used to, due to (what I believe) are heavy 
wing panels.  It would be interesting to know if someone has cut foam 
cores for this model yet....  This also gives a "wallowy" look, if you fly 
too slow which is all to easy to do with the E-setup.  Although the 
general flight is definitately slower than with a glow setup, you need to 
still set the plane in a speed envelope where it "flys" its best.  Also, I 
did not recognize during the build process that the vertical fin has right 
thrust built into it. During building, I added a smidgen more R-thrust, 
and this will now need to be removed.  However, the tip of the rudder 
counterballance is 3/16" off center of the vertical fin, so I don't think 
this amount of offset is entirely due to my little extra R-thrust.

CG:  Mine is flying around 35 mm ahead of the recommended range, and still 
a little tail low.  It is not squatting through radius anymore, and still 
seems to fly light in the pitch axis.  Mixes: only 2% down elevator to low 
throttle.  Although I'm still fiddeling with the tracking (rudder trim, 
wing weight), it seems very close, and no other need for mixing has been 
blareling obvious yet.  In regards to CG, try not to get caught up in 
"simple" tests (or the trim chart) or relative prior experience.  Continue 
to play with the CG until the plane is flying better.

Thanks,
Jim W.



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