Dynam BF-109 CG

[mpence]

I’m setting up the Dynam BF-109 V2 for a club member and have a question on the CG. The manual says 65-70mm from where the wing meets the fuselage. I have a 2200 4S HRB battery all the way forward and even at 70mm it’s still somewhat tail heavy.
I did try a 3600 4S at 70mm and it just balances neutral.
Is anyone else having this problem or am I measuring from the wrong spot. Something tells me it should be at the leading edge of the wing.
Thanks In advance for any help.

[paulrkytek]

I’m setting up the Dynam BF-109 V2 for a club member and have a question on the CG. The manual says 65-70mm from where the wing meets the fuselage. I have a 2200 4S HRB battery all the way forward and even at 70mm it’s still somewhat tail heavy.
I did try a 3600 4S at 70mm and it just balances neutral.
Is anyone else having this problem or am I measuring from the wrong spot. Something tells me it should be at the leading edge of the wing.
Thanks I’m advance for any help.

I would not use leading edge of wing for measurement ref in this this case as this will move cg back which will make it worse. See Bitgo Hobby video on Youtube and go through the q&A comments as this should help. If your club member is not used to warbirds I would be aiming for 60mm back cg as a starting point to be on the safe side even if you have to add some lead to the front. If you fly off grass you may be better off bending the legs or tilting the landing gear forward a bit using a couple of washers under the rear of the retract servo) if you can do it without fouling the wheel wells ( or trim the front of the well otherwise the wheels will hit as they close ) as this will reduce risk of nose overs as the wheels are pretty close to the cg and in an ideal world it would be good to see at least the front half of the wheel when viewed directly from above when the plane has all 3 wheels on the ground. You may need to do a power on landing, touch down on the mains only let it slow and then pin the tail. Go high rate elevator for take offs, starting with full up before applying any power then ease back when moving then catching the tail when it starts to lift off then back to low rate when airborne. Good luck.