Yak 86" Ballance
 

Hey Guys,

Im just ballancing my 86" Yak and having troubles trying to get it to ballance on 188mm.

At the moment its ballancing at the most rear cg marking at 180mm. I have moved all i can move.... I think...

There is a fromeco lithium right on the top front of the motor box, the ignition unit strapped to the side of the motor box, regulator on the other side of the motor box, and batterys and regulator just behind the wing tube.

I have Carbon fiber Spinner, Propeller & Undercarrage.

What else can i do?

RE: Yak 86" Ballance
 

alluminum spinner?

Marc 540[8D]

RE: Yak 86" Ballance
 

Ohh by the way i just finished building my Yak 86" and the final weight of it RTF is 16.1lbs (7.3kg).

Which i think is excellent! What do you think guys?

RE: Yak 86" Ballance
 

Why can't you move these????

RE: Yak 86" Ballance
 

I figured out that i can, i moved them over the fuel tank, seems to be still a little rear cg but it will fly.

RE: Yak 86" Ballance
 

16.1 lbs is going to fly great. I am at 17 lbs and I still have good pull out. I wish I was 16 lbs. You must not be using the cannister?

RE: Yak 86" Ballance
 

Im 16.1lbs with DA-50 on MTW Canister. I have 3 Fromeco 2600's (1 for ignition) (2 for rx & servos), with 2 Fromeco Regulators, Wolverine Dual switch for RX and a Fromeco Badger switch for ignition. Im using 5985's on Elevators & Ailerons, 5955 on Rudder, with standards on throttle and choke.

Im using an XPS 2.4ghz (soon to be FASST), 20oz Dubro Tank, Carbon Undercarrage, Carbon PT Model Prop, Carbon spinner, with light weight Karvan wheels and no wheel pants (as they are not verry scale like)

I could get it under 16lbs by taking the Ignition Regulator and Lithium off and replacing it with a 1800nimh and also putting standard pitts or side dump muffler system. I would be guessing but it would be around 15.5lbs without canister and a lighter system on the ignition.

RE: Yak 86" Ballance
 

Sounds like a good setup....
you will be fine at 16... my 85" is 17lbs and there is PLENTY of power with the DA-fiddy

but... if you wanted to... I only run one 2600(fromeco) and reg to my RX and it works fine... and 20oz is PLENTY.... I have a 16oz and get about 16 to 18min

RE: Yak 86" Ballance
 

Going the 1 battery route for RX would make things lighter but I like have the capacity of 2 2600's and also have redundancy. I was actually thinking about a 16 oz tank but i mentioned it to a friend and he laughed... Said it was to small hehe.

RE: Yak 86" Ballance
 

:)I use a 16oz tank on all my 50cc planes. (DA50 in Yak 86", WH Edge 28%, and AirWild Extra 260) I fly 13 minute flights (timer) and have between 1/3 and 1/2 tank left. I've flown 20minutes before but I was very nervous. Mostly I fly 3D. Mostly slow flights 1/2 to 3/4 throttle. I'd recommend a 16 oz tank.
My QQ weighs 16lbs 4ozs. Mine was very tail heavy also. I added 6ozs of weight to the front the first few flights. After about 5 flights I started taking an oz off every flight. You guessed it...after 6 or 7 flights I had removed all the weight and was very satisfied with the flight performance. You do have to be a bit careful on landing but no problems really. I think I'm at about 178MM right now. After I got used to it I'm fine with it there. I love this plane.

Thanks
Barry

RE: Yak 86" Ballance
 

Thanks for the Reply Barry, So i should be ok to test fly it at 185mm then.

Here are some pics of my final electronics layout. Enjoy

RE: Yak 86" Ballance
 

Very clean set up there. I have to warn you though. The choke and throttle servo plate will want to come loose without washers under the bolt heads. Mine came loose and were installed with blue Locktite in a vertical manner. I dont know how they vibrated up ward. I also have my tray slid all the way back on the fuse and there are 4 bolts going threw the plate on that back section and into the fuse. Still came loose in flight once.

RE: Yak 86" Ballance
 

What did you mean my servo plate? The Servo Tray did you mean to say? I glued mine in with epoxy and screwed it down. So it should not be going anywhere. What did you use loctite on? It should only be used on metal to metal contact, not wood?

RE: Yak 86" Ballance
 

If you epoxied the tray it wil be just fine then.

RE: Yak 86" Ballance
 

epoxied - what to what? Epoxied two plates together or epoxied plates to the motor box?

RE: Yak 86" Ballance
 

rcfreak,

With two batteries installed on the plate like that - do you have enough room for your fingers for safety clip which secures wings?

Pashka

RE: Yak 86" Ballance
 

Yeah just enough room to clip on the wings. And yes epoxy the two plates together and then epoxied it to the motor box with screws also

RE: Yak 86" Ballance
 

Hi some photos of my YAK,
I would like to hear your comments.

RE: Yak 86" Ballance
 

I was thinking about doing what you have done with putting foam on the cowl mounts, fills in the gap between the cowl and the mount, also i think it would be a more snug fit..

Is this the case?

RE: Yak 86" Ballance
 

I tried to take away some of the vibration and it seems to work well until now.
Also I forgot to mention that I have installed titanium rods on the throttle and choke servos.
My C of G is at 182mm

RE: Yak 86" Ballance
 

Is 182mm working well for you? Is it to far back or is it good? Easy or hard to land with that C of G

Also how much does yours weigh, looks like it have heavier batterys and a smoke pump installed with smoke tank.

RE: Yak 86" Ballance
 

I have only 2 flights on the models but 182mm looks perfect.
The batteries weigh 99gr each and I have 3 of them as you see.
Landings are smooth and slow, no problem at all.
I'm waiting for a new aluminum spinner and carbon fiber landing gear and a 6.0v NiCd Battery pack to be installed in the motor box for the smoke pump, then I will know the final weight. I'm expecting the weight at 7,5kg more or less.
Also the smoke tank to be fitted is a smaller one (280ml) and not the one shown in the photo.

RE: Yak 86" Ballance
 

I wanted to know what that yellow mounting material is that you strapped your batterys to. Looks neat. Where can i get some?

I have a Futaba 12FG FASST 2.4ghz system on way and i need to build a little tray for it so the antennas can be routed.

RE: Yak 86" Ballance
 

The yellow material is tygon the same tube which is used for fuel lines.

RE: Yak 86" Ballance
 

RCFREAK Hello again,

The tray material is PC-Board the like the one the horns found in the kit are.
You can find it in electronics shops.