This Hobby is for the Birds!!

[Mr NCT]

This is a Skynetic Bald Eagle from Motion RC.
I saw one of these on youtube and had to have one. The kit was complete only needing glue, receiver and battery. It built in about 4 hours and flew out of my hand at half throttle only needing a little trim - could use some down thrust. What a hoot!!

 

[LitterBug]

I want to 3D print some of the PlanePrint birds.


Birds Aren't Real

 

[leaded50]

el, hopeful you dont have any of the true birds alike around.....then you got a short airfight...

 

[bisco]

very realistic!

 

[badpilot27]

el, hopeful you dont have any of the true birds alike around.....then you got a short airfight...

yeah if you put a cracker in the nose and the whole ecosystem is gonna peck you down lol

 

[Mr NCT]

One odd thing about this kit - the paint came off on my fingers with just normal handling. Took a suggestion from RC Groups and sprayed it with a light coat of water based poly (satin). Not only sealed the paint but also made the colors pop.

 

[Mr NCT]

I'm just finalizing an FB version of the bald eagle at about 80% so more hawk sized. It takes 3 sheets of FB, wingspan of 51 inches and with a B pack,1300 3s battery and 4 9g servos under 500g. I'll probably glide test it into the soy beans before the maiden. Video to follow.

 

[Mr NCT]

It was a perfect day for a maiden - the plane was done. Too bad it was 8mph wind with gusts. I've got some work to do on the wing incidence and thrust angle on the motor. It lives to fly another day.

 

[quorneng]

I made an EDF Sea Gull out of 3mm Depron along the lines of but a bit smaller and lighter than the Plane Print printed version.

48" (1220mm) span it weighs 190g and uses a 30mm EDF with a 450mAh 3s. Flies well enough but it really needs a different wing so it has more "flying wing" longitudinal stability so the very small short moment tail plane is not the primary source.

Needs more work.

 

[bisco]

It was a perfect day for a maiden - the plane was done. Too bad it was 8mph wind with gusts. I've got some work to do on the wing incidence and thrust angle on the motor. It lives to fly another day.

love the soft landings!

 

[Mr NCT]

love the soft landings!

It really does not want to glide. I've flown it a few more times and I keep moving the CG back, It's getting better.

 

[Piotrsko]

You're also missing the onboard multi function controller that real birds have.

 

[LitterBug]

This is how Mine refuels/charges.....

 

[Piotrsko]

Definitely is plug and play, low maintenance costs

 

[LitterBug]

Definitely is plug and play, low maintenance costs

If I put FPV on it and share videos, do I need Part 107???

 

[Mr NCT]

love the soft landings!

I built a sacrificial body (hard to call it a fuselage on a bird) and tried shifting cg, changing wing angle of incidence. Nothing but up elevator would get it to glide. Always a short flight glide straight ahead, no noticeable nose up and stall, then a nose dive. Hmmm

 

[bisco]

at least you have a forgiving flying field

 

[Piotrsko]

Been my experiences that wing profile and high point determines what horizontal stabilization is needed. Ever really look at a Schweitzer 2-33 and the ridiculously small elevator? Rule of thumb: The closer to the leading edge the high point is, the less you need stab area. Birds have their high point really close to the LE. Your gull needs a W (or M?) shape bent wing. Obviously you realize it's at stall, or just above it and isn't generating enough force to overcome the nose down, OR, it ain't flying fast enough. Could use a full.flying stab tail feathers

 

[Mr NCT]

Been my experiences that wing profile and high point determines what horizontal stabilization is needed. Ever really look at a Schweitzer 2-33 and the ridiculously small elevator? Rule of thumb: The closer to the leading edge the high point is, the less you need stab area. Birds have their high point really close to the LE. Your gull needs a W (or M?) shape bent wing. Obviously you realize it's at stall, or just above it and isn't generating enough force to overcome the nose down, OR, it ain't flying fast enough. Could use a full.flying stab tail feathers

Good ideas and it got me researching. I couldn't easily change the high point of the wing but I could put some reflex in the ailerons to give the airfoil more of an 'S' shape as suggested here: https://www.mh-aerotools.de/airfoils/flywing1.htm. I'd had them in line with the top surface of the wing and changed them to about 5 degrees up from the bottom surface, about a 16 degree total change. It didn't drastically affect the glide but it flew WAY better. No need for all the up elevator trim I had given it. Next wing gets the high part of the wing moved forward and the reflex added. Should be much better.

After thought-
Might turn ailerons into flaperons to be able to experiment in flight.

 

[Piotrsko]

Will be really exciting when you go down flap. Btw, birds don't necessarily like being inverted unless they are fighting