orthobird

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hello
i have a seagull Yak 54, 63 inch wingspan ARF

i have installed a OS BGX 1 3500 glow engine
with reinforcement of firewall and everything going to wing tube.

placed all tail servos far back (2 ele + 1 rudder)

have had to add 9 ounces in tail to get balance.

does anyone think this is too much weight for this plane?

scale only 4 me

My Feedback: (158)

Dude what does it weigh??
What's the wingloading?
IMO it's too much Motor for the plane,, LOL

good luck

darrolair

Go for it!!!!!!! Tell us the details....

jetmech05

Over three times the size engine recommended. I like a lot of power too, love the vertical. I wonder if you'll get it to slow down.

RCVFR

My Feedback: (7)

I have one of these I fly with a Zenoah G20. No weight added and it fiies very well.Your engine is at least a pound heavier, plus the additional weight for balance. You will have unlimited vertical, but the non vertical flight could be interesting. Doubtful you will have enough ground clearance to use an appropriate 2 blade prop for your engine, might consider a 3 blade.

It will be an interesting project to see, be sure to take pics.

Balance it just behind the wing tube.

SeamusG

The plane's specs

Specs

Engine Size:	.91–1.25 2- or 4-stroke
Experience Level:	Advanced
Flying Weight:	8.4–9.9 lb
Fuel Type:	Gas
Fuel Type:	Glow
Overall Length:	61.4 in (155.9 cm)
Plane Type:	Aerobatic & 3D
Plane Type:	Scale Civilian
Power Plant Size:	1.10-1.79 2-Cycle Glow
Radio:	6 channels
Recommended Environment:	Outdoor
Servos:	6 servos
Trim Scheme Colors:	Cub Yellow (HANU884) Midnight Blue (HANU885) True Red (HANU866)
Wing Area:	846 sq in (55 sq dm)
Wingspan:	63.4 in (161 cm)

jester_s1

I'd suggest going down to a smaller engine. If you've put 9 ounces in the tail that likely means you have at least an extra 1 1/2 pounds in the nose that the plane wasn't designed for. Not to mention that the fuel consumption is going to be higher which means going to a bigger tank and more takeoff weight. An engine at the top of the manufacturer's recommended range will still give you unlimited vertical with making the plane prone to unpredictable stalls.

darrolair

If he can afford the fuel for that engine, he can afford a new plane when done with the experiment.
Video.........

orthobird

My Feedback: (1)

hi
thanks for comments

the zenoah g20 weighs 41 ounces with ignition and muffler

the os bgx 1 weighs 47 ounces

without muffler

so i am adding additional 10 ounces or so in nose compared to your plane.

it will be interesting to see if it even takes off.

i am going to go for it anyway.

i ordered ultracote clear, waiting for that to arrive so that i can seal the elevator, ailerons, rudder hinge line before the maiden.

orthobird

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i am with you there, it may not even takeoff.

but it sure will be fun to see what happens

LOL

i will do flight in open field, not at a club,

just in case.

no one will be around for miles.
LOL

scale only 4 me

My Feedback: (158)

You forgot to add the fact that unless you're good with a 5 minute flight, you'll want at least a 24 oz tank to quench the thirst of that 35cc glow gulper,, more xtra weight at take off

I'm sure it will get off the ground,, But you go dead stick with this thing, I'm guessing you'll have a space shuttle like glide slope

good luck

orthobird

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i know

it will be like a brick falling from sky.

basically,

if it takes off, i immediately will have to start making approaches to land it.

since flight time will be under 5 minutes.

some calcualtions:
wing area 846 square inches
5.875 sq feet
224 ounces
wing load is 38 ounces per square feet
stall speed is 30 mph

RCVFR

My Feedback: (7)

I run a 12 oz fuel tank, which is good for two 8 min aerobatic flights. Your 24oz tank is a bit more.

The airframe is pretty forgiving and may surprise us all. Please give us a report on how it goes.

Best of luck to you.

SeamusG

Have you seen the YouTube flight where the pilot is flying from a farm road with a HD camera on the plane? There is this grain silo. There is NOTHING ELSE for miles (seems that way at least). Well, he turned his plane into confetti when it hit the silo - and the camera kept running.

So, watch out for those grain silos!

Looking forward to hearing how it went.

orthobird

My Feedback: (1)

the tank that is in there right now is a 10 ounce (350 cc) tank.


just turned engine on:
'
http://www.youtube.com/watch?v=goVhvkjDC2U

i was running it rich


all the glow fuel was gone in under 5 minutes.

ouch.


just ordered a 32 ounce tank from sullivan that will fit right behind firewall with some modifications.

this should give me up to 15 minutes of flight.

the OS handbook for engine states 24 ounces of fuel will be consumed in 10 minutes time.

orthobird

My Feedback: (1)

http://www.youtube.com/watch?v=goVhvkjDC2U

luckily for me, there are no silos in the farm field i will be at.

in NW louisiana, there are plenty of natural gas pumps, which just came about within the past 4 years, and have made many of these landowners very rich.

i wish i had bought this farm land before they found the gas.,

land used to be about 2 to 3000 an acre, now they are selling farm land for 10,000 to 15,000 an acre, is that insane?

it is in middle of nowhere.

they grow cotton, corn, and that is it. usually rotating between the two. the corn has been seen most recently, but it is not for eating, they use the corn to sell to energy companies.

orthobird

My Feedback: (1)

hello there

update

today was the maiden of the Yak 54 with the OS BGX 35 cc glow engine.

total weight dry is 12 pounds.

there is no added weight to it.

the battery pack is placed as far aft in plane.

flight was 8 minutes long.
top speed was 114 mph. total miles travelled was 9 . 3 miles.
whole flight was flown at low low rates. rates were lower than recommended by manual. all servos have metal gears. and there are two servos for the elevator, one on right side and one on left side of tail area. the rudder servo was also placed in tail area.
the throttle servo was placed as far aft as possible in the bay area of fuselage.
the ailerons and elevator hinge areas are sealed with clear ultracoat.
the hinges are dubro pinned hinges.

plane may have been tad nose heavy, and this was adjusted for with inflight trim for up elevator. after trim was done, plane tracked straight and flew like a dream. what a beauty.

was able to fly plane at 1/3 throttle.

plane landed with flaperons, again, very low rate of flap movement.

jester_s1

I'm glad that overpowered beast worked out for you. Have you done any stall testing?

orthobird

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not really.

i did take it up high and brought power all way down, and plane was gliding,
granted the 18 x 10 prop was spinning about 1800 rpm.

when you say stall testing, are you referring to pitch nose up and lower throttle to see if plane is tail heavy vs nose heavy?

orthobird

My Feedback: (1)

hello jester,

jester_s1

I'd say Roy's is the best one, especially for selection. Just don't ask them to explain anything to you or help you solve a problem. Some like Mike's Hobby in Carrolton, but I've never been there. One of the neater shops is Airport Pawn in North Richland Hills. They have lots of used stuff if that's your thing.

By stall testing, I just meant cutting the power and holding it level to see how it acts in a stall. As you probably know, heavy planes can be ornery at much higher speeds than lighter ones.

orthobird

My Feedback: (1)

yes

i see what you are saying.

because the plane is 2 pounds over, when i was coming in for landing, it was not
how should i say,
the most stable plane

meaning, it did want to roll one way or other, i just quickly reacted to counter that
and was able to make a smooth landing

i guess if i tried to land with some more speed on. then it would not have done this.

is this referred to as tip stalling?

scale only 4 me

My Feedback: (158)

Not a bad idea to do some "high speed stall" testing too, high wingloading and a forward CG can make for a snappy bird. Take it up high and at high spedd pull full up and see if it goes into a snap,, I had this Yak-9 warbird racer that would do a perfect 3/4 snap,, needless to say it wasn't the best for pylon racing

good luck

jester_s1

Yes, when a wingtip drops that's a tip stall. For future reference, the right way to react to a tip stall is to rudder it the other way, not to apply ailerons. If the wing gets far enough into a tip stall and you correct it with aileron, you'll actually make the stall worse and the plane will continue dropping the wingtip even faster than before. If that happens on landing, about .2 seconds later the plane goes cartwheeling down the runway.

RCVFR

My Feedback: (7)

Earlier, you mentioned you are using flapperons. This will worsen the tip stall tendencies of the overweight plane. It's good you got it back down successfully. You may notice planes that are equipped with flaps have them on the inboard section of the wing panels. There is a reason for that. Flapperons can be interesting on non symmetrical lightly loaded airfoils. Not so much fun on a set up like yours. Congrats on a successful maiden.