Clipped, Electric weight, E-Impact first flights

[Jim_Woodward at beaerospace.com]

(2nd attempt)
Jim O.,

I'm not sure what gear box I have, as I'm not really familiar with the 
previous Hacker motors.  I do see some bolt heads on the back of the 
motor, which would suggest to me that they run through the motor and into 
the gear box in the front.  At the front of the gear box, all you see is 
the bearing with the actual receiving holes for the motor-mounting screws. 
 

I flew the Impact 4 flights this weekend.  I did this while flying my 
Aggressor, and breaking in a new OS 140 RX.  It was one of the funnest, 
BEST pattern day's I've ever had.  I flew the E-Impact and immediately 
liked the power and speed control (and ease).  The Impact itself, didn't 
jump off the board as a perfectly trimmed plane, so I knew I had a little 
work to do.  After the first flight, the concept was DEFINITELY proven, 
and I quickly deduced that I need more batteries (first flight was 
Saturday evening).  After this first flight (with John B. from Surinam 
watching), we determined the need to paint the bottom of the wings and 
canopy.  We ran to Lowes and bought some florescent red/orange to paint 
the stab and wing tips, and we also painted the canopy metallic silver. 
Also determined that the plane was tail heavy quite a bit.  Anyone 
familiar with the Impact thread on RCU knows exactly what I'm talking 
about in regards to the Impact. 

Sunday morning with CG moved forward, the plane flew better and the small 
amount of color we put on the plane definitely made a huge difference. 
After this second flight, also determined that the CG was still too far 
aft, and that the battery needed to be moved forward (at this point, knife 
edge needed no mixing), and the plane was carrying a small amount of 
aileron trim. 

Then, I flew the Aggressor for the first flight with the OS 140 RX and 
17x10 APC.  With th 17x10, the OS was nearly "super-sonic" compared to the 
Impact, however immediately, the Aggressor's trimmed status and 
"locked-on" look/feel was evident (as anyone who has seen the plane fly in 
D3 would attest to.  Due to charging time of the E-Impact, I swapped props 
to the Mez 18x10, adjusted the throttle curve, and started moving the 
speed envelope of the Aggressor down to match the Impact in a couple more 
flights.  My first thought was that if I had the E-setup in the Aggressor, 
it would be an unstoppable machine!  (Aggressor weight without fuel is 10 
lbs 13 oz).

Time for another flight on the Impact.  I flew through PO5 this time, and 
started getting used to the E-power curve, some rates, etc.  The forward 
CG move started to pay off, and the plane was drawing better lines (but 
still not like my glow plane, which is understandable as this was only the 
third flight on the model). After this flight, again, decided the CG 
needed to go MORE forward.  Also, we determined that the right wing tip 
needed about 14 grams of weight to laterally balance the model (a step I 
did not do in the garage, we added the tip weight at the field).

Back to the Aggressor:  I flew two more flight back to back on the 
Aggressor, each time improving the throttle curve to make it easier to 
match the envelop of the Impact.  The OS ran perfect, and I'm sad that 
after 5 years of screwing with other engines, to have not just spent the 
little bit of extra money and ran the OS all along.  Through each flight 
(90 degrees, 90% humidity), the OS ran superb.  Inflight throttling was 
great, you could tell the motor was not getting hot, and it was making 
ridiculous vertical power.  (by the way, this was on an OS A5 plug, C.P. 
25% pro-pattern, and ES pipe).  The OS runs VERY smooth with a crazy low 
idle.  I'm VERY happy with how it ran - not a single dead stick through 
its first 5 flights - nothing but awesome performance.  The locked in 
(trimmed) status of the Aggressor, now flying in the slower speed 
enveloped, had convinced John that this was still the "ticket" as compared 
to where the Impact was after 3 flights.

Back to the E-Impact!!!!!!!!!!  For this flight, the 6000 Pro-Lite T.P. 
battery was moved as far forward as possible (just behind motor).  This 
flight showed some incredible potential.  In this CG config., the Impact 
was driving lines similar to the Aggressor (up, down, 45's, etc), and 
rolling VERY well.  Also, the wing tip weight on the right wing made EVERY 
SINGLE MANEUVER look better.  The wings were much more locked on, the 
plane rolled better, exited snaps better, spinned better.  This was a 
great trimming lesson to me, as the day was getting cross-windy (worse) 
through out the day as the ruminants of the tropical storm passed through, 
however in the worsening conditions, this was the BEST of the flights.. 
After this flight, John immediately was convinced that this was indeed 
going to be a solid backup or first plane for the nats.  I'm still going 
to move the receiver battery forward now though, and probably make a 
lighter rudder (which wouldn't hurt things anyway).  (hacker controller 
has 3 degrees timing).

Charging:  I alternated by charging from the car battery, then letting the 
car idle for the next charge (guess what - no big deal to do this if 
necessary).  However my limitation is that I only have one Astro 109 as 
the second one has not arrived yet.  Thus, instead of 45 minute turnaround 
times, I was 1.5 hrs between flights.

Impact:  I followed some RCU advice and started with a CG on the center of 
the wing tube, without wings on.  This is in serious error.  However, the 
plane will dive mildly when in inverted flight, and it gives the 
impression through simple tests that the CG is correct.  With this CG, the 
plane flys off the tail.  In radius, the tails squats and the plane will 
fly tail low.  After I was done with it, the plane was following the nose, 
driving excellent lines, similar to the Aggressor (still thanking Tony F. 
for the trimming help on my Lazulite,which has now gone into all my 
planes!).

Glow / Electric:  In a quick comparison, a trimmed plane is what you need. 
 Electric power itself will help with presentation and probably hide some 
airplane tendencies (if bad), due to the smaller speed envelope. Although, 
the power and the plane are working together, they are still a bit 
separate.  I guess I'm trying to say that a poorly trimmed plane is going 
to hurt you no matter what motor you have in it.  I'm guessing purely 
guessing now though, that if two identical planes, both completely 
trimmed, were equipped with glow and electric, that the E-setup would take 
the cake as it would allow more of a "show-casing" of the maneuver set. 
More to follow.........

Thanks, welcome questions, comments, public or private.

Jim W.

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