raydar

Your use of the bigger engine is a classic example of a bigger engine not always being better.

I always try fit as much power to a model as I can but as soon as thinkI have to add weight to the tail or substantially add weight by major reinforcement to handle the engine I knowI have reached the limit of the airframe and rethink myengine choice. The new light 20 cc petrol motors are best suited to this model ora 120two stroke glow, much more engine thanthis then you start to reach the point of compromisingflight characteristics for all out power.Now your plane is under 12 pounds she sould fly ok, with bags of power but she wont fly as well as a lighter model with a smaller engine, personally I would still not be happy with this set up.

I understand sometimes weare restricted by what engine is available to yourself, it would be a expensive hobby if we bought a new engine for every model we built. Having said that I just had a look at the os bgx, looking at the prop choices it seems it would be better suited for a 30 cc airframe, maybe someone else with big glow engine experience could comfirm this.There is alot of nice flying 72 inch wingspan acrobatic models out there that would build about 12 to 13 pounds with your engine and fly much better than the seagull yak with a heavy nose.

at least after you have outgrown the seagull yak you have the perfect engine for a new 30cc model

Dle 20 is 29 oz with ignition and muffler, uses 8 oz fuel tank and 4 oz ignition battery (optional with battery share), total weight 41 oz

OS 35 bgx 47 oz WITHOUT muffler, uses 2 oz per minute so say 24 oz tank, total weight without muffler 71 oz.

Prob double the weight of the dle set up when the muffler is fitted.

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 back 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.

lopflyers

My Feedback: (12)

Anybody knows what size the stock spinner is? I want to put an aluminum one but the one I'm using is way too big

navypoe1

Stock spinner is 2.75".

lopflyers

My Feedback: (12)

Thx navypoe

orthobird

My Feedback: (1)

new update, for all of you who said

i told you so,

here is the bottom line

today, plane flew fine on first flight.


i heard something funny and brought plane down. smooth landing.

i turned engine on, and the rear muffler spout was spinning over its screw.  i tightnened it

and took plane off again, this time, i used high rates for elevator only.


after three tight turns, plane began to act funny,

the wings were fluttering

and then when i brought power down, plane fell from sky like a pancake.


it is toast


i saw that on one aileron servo, the screw came off,

so it appears i lost one control surface, and this was cause of demise


no matter what

plane was way over powered with the OS BGX 35 cc glow 2 cycle engine


it was fun while it lasted.


anyone have any suggestions on a bird i could put this engine in?

lopflyers

My Feedback: (12)

What????? I'm sorry you lost your plane. I still think that is too much engine for this airframe.

orthobird

My Feedback: (1)

yes
no doubt.

that plane was a screamer for the three flights it had.


i can say this, i have learned my lesson

everyone else says it

a bigger engine does not necessarily mean, it will be faster and better.

so

from now on, i will stick with engines recommended for the plane,
and

after i read reviews on plane, i will choose engine.

Sourkraut

Sorry for your loss.....mine is still flying great. I am into my second season with her and the Saito 180 is a puuuurrrrffffect match for this airframe.

orthobird

My Feedback: (1)

confucius says:
panty not best thing in the world
but next to best thing in the world

LonestarMan

I got the same bird w/ a DLE 20 in it. Havent flown it yet, been too windy here. Remember this is a .90-sized bird. You essentially put 4 times the recommended engine in it. My friend just yesterday flew his G.P. Sukhoi giant scale & it had more than enough power with the same motor.Sorry, but for me, i dont have "disposable planes" like that.

lopflyers

My Feedback: (12)

Ohhhh, I feel so much better, after about 1 month of no flying due to a combo of factors ( work, rain, rain, work) I finally flew four flights today.

sled

I need help with the throttle linkage on this Yak with a DLE 20. To date my efforts to reslove this problem just don't meet my standards (just to much of a perfectionist I guess). With the gas tank in the stock location and the throttle servo mounted on the left side of the fuse, just behind the wing tube. The Golden Rod (red version) I plan on using for the throttle linkage has to snake around the tank to make it to the throttle location on the DLE. The bends I have to make in the Golden Rod violate the minimun bend raidus of the product & make the movement of the linkage somewhat stiff. And ther ain't a whole lot of room behind the fire wall[]

Any help or suggestions for a solution would be greatly appericated, more so if they include pic's

Thanks
sled

Indiomike

My Feedback: (5)

sled

My Yak has the DLE20 and I use the red Sullivan semi flexible nyrod as you describe. After the tube goes through the engine box it faces the hole in a vertical glued plywood plate which supports the front of the fuel tank. I ran my nyrod to the outside of that plate and then over the top of the wing tube to the throttle servo. My throttle works fine with no binding. I may put a dab of glue on the nyrod where it lays across the wing tube just to keep it a tad stiffer.

sled

Indiomike

Thanks for the idea and the pisc. Time to get busy on the interio of the Yak!

sled

gade600sdi

Make sure your Yak is reliable engine. This model is fine when under power, when it loses power it becomes a flying brick. 3 of them at our club and all are no longer with us after the first dead stick (seasoned pilots). If your engine quits do yourself a favor , nose it down and go straight into the ground, make it spectacular....... dont try to save it the end result will be the same anyway. It will stall bad on you and there little chance of saving it unless you have a lot of altitude and a lot of luck and a lot of skill. And you will need all three to make it back.

bgw45

My Feedback: (1)

Not my experience. I did lose mine attempting to do a rolling circle on take-off ( another jughead move on my part ), but it would fly in on a dead-stick. It only weighed 9.5 after a diet. Yes, you need to keep a constant even decent, but it is easily doable. The airframe has to be balanced correctly or your doomed but that goes with most airframes. I had three different engines on mine ( Saito .91, Evolution 1.20 and finally a DLE20 ). Had successful dead-sticks with all of them.

Keep the weight down and relax and enjoy it.

lopflyers

My Feedback: (12)

Mine deadstick with a Saito 100, w that engine to reach the CG I had to add a lot of lead to the nose because it was very tail heavy. I landed it without problems.
Now it has a TT 120, it balanced with no extra weight. It is a lot faster and funner to fly. I have 9 planes RTF and this is my prefered, by the looks in the pitts and the performance in the air.


 

RCVFR

My Feedback: (7)

Not my experience, at all. I have owned three of them, the first with a balky RCGF 26 that quit repeatedly before the ignition gave out totally. It was a surprisingly excellent "glider'. same engine later shed the prop driver, prop and spinner in flight causing severe tail heavy condition, and the plane was landed with no further damage.

If you have experienced bad dead stick flight, it's not the fault of the airframe. Look elsewhere.

navypoe1

Yeah...Do not just nose dive it in the ground if the engine dies. I have a ST 2500 on mine with 4oz tail weight added. If you have it balanced right it will glide just fine.

ScottMcM

My Feedback: (66)

I have a DLE 20 on mine, and one of my buddies had a DLE 30 on his. We both had several deadsticks before we got the engine dialed in, and never had a problem landing. I still have mine, while his was eventually lost to flutter[:@]

AA5BY

In my opinion, Yak's are a little vulnerable to sharp rolls when landing cross wind. I don't see it as tip stall but rather a sudden roll induced by wind hitting the generous vertical stab and canopy/aft deck. Three feet off the deck is quite unappreciated. My reason for not thinking they are tip stalls is that a quick response will roll it back level. If a wing had stalled, I don't think it would be recoverable.

I've saved mine several times by quick response to such sudden rolls just above the deck and now with a seeming understanding of what is happening, I now avoid flying during gusty cross wind conditions and take the stick rather than the Yak.

raydar

lol this plane floats in deadstick at 10 pounds 8 oz with dle 20. dont just ditch it if you deadstick, go have your lunch till the plane losses altitude then come back and land it.

proteus_X3

My Feedback: (16)

Great thread,read all 61 pages of it. Going to put a Zenoah G20 that I have sitting on my work bench. mine is the Yellow and Black  model it will be a while before I get to it. Cheers: Rich

captinjohn

How do you think a Saito 1.50 would work on this airplane? Thanks Capt,n