Hello guys , iam having a hard time balancing this plane , the recomended COG is 2.7 in from the leading edge of the wing . Although there is an other cog in the manual which calls it at 2.5 in from the leading edge . When i try balancing the plane at 2.7 in COG it comes out very tail heavy , i had to add 70g of weight to balance it . What should be the COG ? My setup is electric iam using the following.
Zippy compact 3700 mah 5s
Turnigy plush 60a esc
Turnigy g46 550kv motor

Any help would be appriciated

@rajjaiswal92
Specs say 70mm/2.7" from LE.
Specs also say 4-6 cell, 4-5000mah battery.
That would probably be 70-100gms heavier than your 5s 3700mah.
So she probably needs that much extra weight in the nose.
As you may already know, the biggest risk for a test flight is tail heaviness...

K K Iyer is right

what i do on my models ,
move battery little bit forward to balance the plane c.g

i  change the position of landing gear also for c.g little bit

i use wolfpack lipo i got 10 to 20 grm weight variation in same range of battery  so its comman problem

Quote from: K K Iyer on November 05, 2014, 04:11:02 PM
@rajjaiswal92
Specs say 70mm/2.7" from LE.
Specs also say 4-6 cell, 4-5000mah battery.
That would probably be 70-100gms heavier than your 5s 3700mah.
So she probably needs that much extra weight in the nose.
As you may already know, the biggest risk for a test flight is tail heaviness...

This what iam worried about sir , guess i'll wait for the 12*10 prop to come that prop should get the watts up and maybe add a bit more thrust .

Oh sir btw i set my lipo alarm at 3.7 per cell and ran the motor constantly at 75% throttle got around about of 6.5 min of time

Vin ,
If i could have moved the battery even by a mm i would have .

@rajjaiswal92
There are three separate issues. Don't mix them up.
1. Tail heavy. Risky, especially for test flight. You can solve this by adding nose weight. Like used lead weights from tyre balancing shop, or old pencells (17gms each). You can tape under the nose if no space inside.
2. Underpowered. Risky, especially for test flight. You can check this easily. If your existing motor/prop/battery combo can lift the model vertically, it means you have power/weight ratio of at least 1:1, which is more than adequate for test flight. Provided you have at least 6" pitch, preferably 8".
3. Battery capacity. 2-4 minutes is quite enough for test flight

Hope you have a successful test flight tomorrow (holiday)

@rajjaiswal92
Happy about your successful maiden.
Do take a video on Sunday.
So which prop did you use?

thank you Iyer sir , i used a 12*8 prop (more than enough power for me)

i had to use 3cells to balnce the cg (70g) now will use a 5000 mah to increase flight time