Balance 86 Yak

[mark nichols]

Hi Guys have setup and installation as manual except a carbon spinner not alloy and 2500nimh pack in motor box for ignition. Plane is tail heavy when balancing. So moved 4300durallite side of motor box and have added a combined total of 160grams of stick on weights to front top and bottom of motor box, balances at 190 fine. This seems like a lot of weight and wondering if anyone else fitting carbon spinner had the same. I imagine an alloy spinner would weigh a lot also. Balanced on an EZ Balancer but the balancer seems exceptionally good, same when i balanced on fingers just easier with balancer.

A tru turn 4"spinner weighs 5.8oz which is 168 grams, so with both batteries in the motor box and the spinner id of thought i should be slightly nose heavy.

Any feedback very welcome as i want to maiden this week.

Mark

[emvin]

Hey Mark, sounds heavy to me, however, when I maidened mine I moved all weight to the front as well . I was running 3 -6v nmh 2000ma + 1 - 4.8 (as dead weight) just to balance at the middle of the measurments provided in the manual. That was fine for the maiden This was also my first 50cc plane and was a bit nervous. After the first five or so flights I realized that is was to nose heavy. 3d performance was not up to par. I spoke with Quique and he told me that the CG measurements in the manual are concervative. After that conversaton I had the confidence to start moving things back. Got rid of the dead weight and moved one of my rx bateries behind the fuel tank. What a difference hovers were locking in and flat spins were easier as well. Next was landing (thats what I was worried about) No problem still very stable trainer like I now have both RX batteries behind the fuel tank, the ignition batt is still up in the nose there is no spinner and I am running a stock DA50 muffler. it may be to tail heavy for some, but, for me its perfect. Good Luck.


EMVIN

[mark nichols]

Thanks Emvin
Its a worry when its youre first 50cc class plane and then you follow the manual and end up with different cg with exactly the same parts except alloy spinner. Iam going to move my duralitte battery back to manual placement and then leave nose weight in for maiden I have a very experienced flyer who iam visiting 200 miles away to maiden with after a thorough check by him of setup. So i was hoping to iron all issues out and get a good days flying and tweeking, when i see him

Anyway thanks again its good to have a reply off someone flying the yak.

Mark

[Reza]

Mark,

Are you using a Carbon Prop? CF prop is about 2 oz heavier than wood.
If you have your battery on the engine box, you are a little nose heavy. Don't worry about what the balancer shows you, fly it! You can remove the weight but leave it for your first flight.

Thank you,
Reza

	Quote: Originally Posted by mark nichols
	Hi Guys have setup and installation as manual except a carbon spinner not alloy and 2500nimh pack in motor box for ignition. Plane is tail heavy when balancing. So moved 4300durallite side of motor box and have added a combined total of 160grams of stick on weights to front top and bottom of motor box, balances at 190 fine. This seems like a lot of weight and wondering if anyone else fitting carbon spinner had the same. I imagine an alloy spinner would weigh a lot also. Balanced on an EZ Balancer but the balancer seems exceptionally good, same when i balanced on fingers just easier with balancer. A tru turn 4"spinner weighs 5.8oz which is 168 grams, so with both batteries in the motor box and the spinner id of thought i should be slightly nose heavy. Any feedback very welcome as i want to maiden this week. Mark

[mark nichols]

Thanks Reza

Iam using carbon prop will leave battery in nose for the first flights.

Thanks again Reza and Molly

Mark

[peter_j]

how are yall doing, this is my first big plane. mine has a 2700 4 cell in the nose, pitts muffler, wood prop and my rx battery is a sub c 3300mah (big pack). mine is balanced at 188mm mark, i mounted the rx battery on the bulkhead behind the wing tube,long ways vertically. first flight was on tuesday, i havent done too much 3D yet, but it flat spins, and lands great. however i think it is still nose heavy. once my knees stop shaking i'll start making small cg changes.

[mark nichols]

Hi Guys,

We got DA running like clockwork, had to put test flight off for a few days as had loose tyres on hubs and they where catching bigtime when loaded on lg, best to be safe than sorry. Anyway have moved battery back to manual position as the cowl wouldnt go on with battery on side of engine box. Ive left left 160grams nose weight (which is same as spinner). Anyway this should be ok i hope, will silicoln tyres on hubs then finger balance and then fly.

Going to fly midweek so will report back, hopefully the plane wont shock me being tail heavy.

Mark

[pani]

Hi Mark,

How did it go?

panos

[TazmanianDevil]

Hi Mark

Good luck with the maiden flight!
Dont forget to send the pictures.

Adi

[mark nichols]

Hi Guys, weve tried twice to get it maiden and had major wind problems blowing 20 steady and gusting real bad. When its not windy it's raining. Anyway so plenty taxi practice and engine starts etc, ironing all small problems like cowl nuts, re route vent etc. Hopefully Saturday looks good here so fingers crossed.

Mark

[Atarget1]

Cheers and good luck mate!!

[mark nichols]

Well finally maidened, battery stock manual position tru turn spinner and 100 gm on engine box balanced perfect at 188 and flew superb. Incredibly stable easy flying plane. Maidened a ef 58 extra glow os 91 what a twitchy plane after the big one. Just have to decide when to switch to my JR 2.4 instead of futaba to use the throttle curve!

Pic is with adi's wing bags form covermewingbags.com, a really nice guy with a good product. Thanks for all your help guys and especially reza and the team for a sweet plane and great support.

Mark