I decided to make one of those FFF Eagles:
1500kv Blue Wonder
GWS 9050hd
TP 2s910
OEMRC 18A esc
2x HXT500 servos (R/E)
HXT900 servo (ail)
AUW = 22oz

Feels like it's underpowered, but I'm used to a solid 2:1 . It does get up there though, and once I got used to it I was able to do some tight circles good enough for any thermal. I can't believe how tough it is though. During the maiden my rx had a broken xtal, which ended up with a WOT vertical nose dive! The nose was accordioned a little, which I thought was amazing for an fff plane. That big nose with doublers and it's relative light weight sure must help in that department. Anyhow, you can see from the pics that it still flies well.

FWIW, I added 2 pics showing details of my tail mount. I had a hard time swallowing what other ppl were doing to secure the V-tail, so I thought it out a little. The method I came up with is very strong, light, clean, and best of all easy to do. Skewers would work just as well, but I already had the carbon and dremel out... so...

Cheers,
Kev

I just finished my second Eagle build. My first was the 42" version. After seeing mine, a fellow flier just had to have one too, but he wanted the 56" version. I added some glass eyes from a 'trashed stuff animal' from the local Goodwill. This one is a bit over powered. The owner wanted to use what he had on hand so this one is powered by a Mega 16-15-4. On 2S and a 7x4 prop I'm pulling ~18 amps and 140+ watts. I don't think it'll be doing much full throttle flying.

Originally Posted by Vantasstic

I just finished my second Eagle build. My first was the 42" version. After seeing mine, a fellow flier just had to have one too, but he wanted the 56" version. I added some glass eyes from a 'trashed stuff animal' from the local Goodwill. This one is a bit over powered. The owner wanted to use what he had on hand so this one is powered by a Mega 16-15-4. On 2S and a 7x4 prop I'm pulling ~18 amps and 140+ watts. I don't think it'll be doing much full throttle flying.

Great work Van! I am looking for a gearbox for my Mega 16-15-2.
It's just to hot for my applications. jp

We continue to play with the elevon set up and the elevator on the Peregrine. Once we glued the big tail to an unmoving surface it was hard to get enough up and down response with the elevons. When the tail (elevator) was loose it worked better than after it was glued solidly in place. The aileron-elevator works better than the elevons.

I also have screwed the wing down solidly with hardware showed previously. The Velcro is a good idea but it allows some wing movement even though the Velcro is attached.

I have been playing with the motor angle again since I screwed the wing down and have added a little down thrust to the motor.

Lee,
I love my Peregrine! It's been fun as well as a challenge getting the bird set up. I now have the trims adjusted where I can get it to fly. The main problem I am having is alot of wing flutter. Both wings vibrate pretty violently every so often. It occurs even in level flight. I have tried to adjust the ailerons but still have the problem. I have both ailerons in the same orientation as the line of thrust of the prop which is the same as the flat bottom surface of the plane. This makes them trimmed up in relation to the trailing edge of the wing. (I hope that makes sense) Any suggestions?
I painted the plane to resemble a Red Tail Hawk which is the most common bird of prey in the South. I would post pictures but I can't figure out how. Thanks,
Martin

I have seen the flutter but it has been at high speed and is not common. We flew the Peregrine for about 3 batteries Saturday which is probably an hour of air time because I seldom am more than 60% throttle. At 100% it goes vertical. We had redtail hawks hovering over us again but no strike.

The plane was origionally flown with a BW1300 and the plane was lighter and slower. Now I am flying with the CF2812 and the BP21 and the plane will literally go vertical. I have only seen the flutter at WOT in strafing runs. It is so seldom that I haven't worried about it realizing this is not a fighter even though I fly it like one.

I fly these planes a lot and have them trimmed in so well I will let the beginenrs fly them.

I am thinking that if the flutter is a problem it might be good to put another flat spar in the top of the wing with a razor blade slit like we did in the bottom. The two spars would make an I beam and add alot of strength to the wing. I like this idea because it wouldn't mess up the paint job and won't cost much. The wing could possibly twist with this I beam but this would add a lot of strength. A third spar set towards the TE of the wing would prevent twist in the main core of the wing

How much slop do you have in your hinges? aileron connections? are your servos moving in the EPP foam?

Maybe I can get the flutter to show up on tape and slow it down to look at it. I appreciate the input. This is a great plane and will out fly any trainer plus it looks great in the sky.

Lee

Lee,
Thanks for the suggestions. I will give that a try. I am using tape hinges the length of the ailerons and they seem to be solid. The servos also seem to be solid in the pockets melted into the wing. When your plane is trimmed properly are the ailerons trimmed up or are they even with the trailing wedge of the wing?
Martin

Originally Posted by Truglodite

I decided to make one of those FFF Eagles:
1500kv Blue Wonder
GWS 9050hd
TP 2s910
OEMRC 18A esc
2x HXT500 servos (R/E)
HXT900 servo (ail)
AUW = 22oz

Feels like it's underpowered, but I'm used to a solid 2:1 .

I was flying mine on a 1300kv BW and a 3 cell. I found that it flew fine once I got it to altitude, but the climb was slow. I did put a bigger 46 gram 1000kv motor on it recently just to get a better climb, but once I'm up where I want to be I fly it on low power and there isn't much difference.

Originally Posted by Bhamflyer

Lee,
Thanks for the suggestions. I will give that a try. I am using tape hinges the length of the ailerons and they seem to be solid. The servos also seem to be solid in the pockets melted into the wing. When your plane is trimmed properly are the ailerons trimmed up or are they even with the trailing wedge of the wing?
Martin

They are just a trace up plus the ailerons are built with a little reflux even when they look level.

Originally Posted by billwhit

I was flying mine on a 1300kv BW and a 3 cell. I found that it flew fine once I got it to altitude, but the climb was slow. I did put a bigger 46 gram 1000kv motor on it recently just to get a better climb, but once I'm up where I want to be I fly it on low power and there isn't much difference.

Good to hear the cruise isn't affected by the added weight. I actually have about 2oz of lead in the beak, lol, and a spare kda20-22L (888kV/67% via bench test) in my box, but not sure how heavy I should go with my prop/lipo combo. What prop/lipo did you use with your 46gm 1000kV? I'm assuming the amps are more than a 2s900 should be doing.

It is quite a novelty in itself that a relatively monstrous plane manages to get any lift at all with a 24gm motor. That alone makes me want to keep it as is, lol. I hardly notice a difference between WOT and glide, except that at WOT it (very gradually) gains altitude. Gliding? Not the best L/D, let's just put it that way. Even with my flea size gear I'd estimate a 2:1 glide ratio. The cool part is it maintains altitude at half to 3/4 throttle. From my bench testing, 3/4 throttle is like 2A versus 9A at WOT. So the duration is very appealing.

Cheers,
Kev

Originally Posted by Truglodite

Good to hear the cruise isn't affected by the added weight. I actually have about 2oz of lead in the beak, lol, and a spare kda20-22L (888kV/67% via bench test) in my box, but not sure how heavy I should go with my prop/lipo combo. What prop/lipo did you use with your 46gm 1000kV? I'm assuming the amps are more than a 2s900 should be doing.

It is quite a novelty in itself that a relatively monstrous plane manages to get any lift at all with a 24gm motor. That alone makes me want to keep it as is, lol. I hardly notice a difference between WOT and glide, except that at WOT it (very gradually) gains altitude. Gliding? Not the best L/D, let's just put it that way. Even with my flea size gear I'd estimate a 2:1 glide ratio. The cool part is it maintains altitude at half to 3/4 throttle. From my bench testing, 3/4 throttle is like 2A versus 9A at WOT. So the duration is very appealing.

Cheers,
Kev

Yes, running it on the BW is amusing. I didn't really have a desire to change it until I flew with a friend that had a larger motor in his. I would be slowly climbing while he was already at altitude. Once I was up there though, you wouldn't know a difference. I did have flights well over 15 minute on it too.

I am using a 1000mAh 3 cell 15-20c, my current power setup pulls just under 12 amps at WOT. I fly my eagle with a 3.5 Oz camera mounted on the head so that took care of the nose weight. It will fly with a 1300 mAh as well, if I took the camera out I would need to use the 1300 and have it as far forward as possible. When i gained the extra 20 grams from the new motor I switched from the 1300 to the 1000 to even it out.

After my recent eagle attack I feel a little better with some extra power in case I need it, but I am still a big fan of the BW motors.

Happy flying!

I flew my eagle last evening at a park down the street for the first time. I took it up about 200-300 ft., throttled back to about 1/3 throttle where you can't hear any motor noise or notice the spinning prop, and just lazily circled around. It was interesting to see people out taking walks, tennis players, and even cars slow down to look. I heard a couple of onlookers stop and remark, "Look at the bald eagle!" Everyone was totally fooled. They didn't notice me off to one corner with my transmitter!

It wasn't until I did a loop with an Immelman exit that they realized the ruse. Still waiting for some big bird encounters, though.

Originally Posted by Truglodite

Good to hear the cruise isn't affected by the added weight. I actually have about 2oz of lead in the beak, lol, and a spare kda20-22L (888kV/67% via bench test) in my box, but not sure how heavy I should go with my prop/lipo combo. What prop/lipo did you use with your 46gm 1000kV? I'm assuming the amps are more than a 2s900 should be doing.
...Kev

Kev... I have that same KDA outrunner... it's too much motor for the eagle, unless you intentionally under-prop it. And then you'd be better off with a smaller, higher kV motor spinning a slightly smaller prop and/or a larger battery. I have the HL SK400XT in mine spinning a GWS 9x5DD prop with a 3S 1300 mAh pack. It's a perfect power setup for fast climbing/escape maneuvers, weight distribution, and flight duration. The HC Turnigy 2209-28 is a less expensive motor equivalent in size and power to the SK400XT.

The Eagle I built for a fellow flier did it's maiden last weekend with no problems. Powered with a Mega 16-15-4, GWS 7x4 prop (cut down from an 8-4) on a 2S LiPo I was measuring ~18 amps. The owner only had 3S packs, so he flew it off that. I'd bet it'd be in the mid 20A range. Climb power was not a problem, he barely broke 1/2 throttle, and did ~10-12 minutes using only 697mA out of his 1300mAh pack. He's a happy Eagle owner.

I have the 42" version and noted a couple of flight differenences. Mine has no dihedral (save the wing tips) and my aileron response is pretty good and rudder response in not. His is the 56" version with dihedral in the main wing. His rudder was very responsive (and would also dive the Eagle), but his ailerons were not very sensitive at all.

As for flying with the real winged wonders...we had a conversation on that. It appears he who has more altitude is the 'Alpha' bird...anything below the highest bird is fair game. So...if in the vicinity or real ones...just fly higher than them and (maybe) you'll be okay.

Watch this

http://vimeo.com/moogaloop.swf?clip_...r=vimeo.com&sh

Originally Posted by Lee

Watch this

http://vimeo.com/moogaloop.swf?clip_...r=vimeo.com&sh

And its just as dangerous as it looks, there have been some horrific accidents. Shane McKonkey, who was arguably the best ski-base jumper in the world died this spring when a ski wouldn't release.
http://www.straight.com/article-2101...s-base-jumping

Rick.