FMS F4U 1700mm Corsair

[Sky King]

CG question. The original 120mm back from leading edge was changed to 100mm back on strong advise from another builder on U Tube. But this turns out to be way too forward. What are other owners of the Corsair using for CG range?

[bradl4648]

Hi do not forget to have the gear in the retracted position on this plane (gear in the wheel wells) do to the tires go AFT. If you balance this plane gear down it will be tail heavy when you retract them. Once you deploy the gear it will be a little nose heavy but that will not hurt a thing.

[xviper]

I can't remember exactly where I balanced mine but you do realize that it is a given that you need many, many ouces of lead in cowl to make it work. A forward CG will make this plane fly better and safer but it needs a lot of additional lead weight stuck around the inside of that round cowl. I recall mine has 5 to 6 ounces of those sticky tire balance weights, maybe more.

[TiredIronGRB]

Mine (V2) balances with a 6S 4000 with no weight.

[xviper]

Mine (V2) balances with a 6S 4000 with no weight.

That's quite amazing. Most I've seen and read about use a 5000mah bat and still need gobs of lead. There are 2 at my field and both are loaded. I've also seen this in the RCG thread. Mind you, this may only be with V1.

[TiredIronGRB]

That's quite amazing. Most I've seen and read about use a 5000mah bat and still need gobs of lead. There are 2 at my field and both are loaded. I've also seen this in the RCG thread. Mind you, this may only be with V1.

The V2 has the metal motor mount so that may be part of it.

[TiredIronGRB]

I just rechecked mine and it balances at 110mm.

[0nemildot]

Any reason not to use a larger battery to address the CG issues without lead up front? I have been on the fence for a long time and am getting closer, Would a 6000mah 6s or 2 3300mah in parallel fit?

Seems this bird flies well, but has a bad history of hit or miss QC issues. You guys flying new ones like them?

[redtwilight]

I've got a 5000mah battery shoved all the way forward, a second 2s 2200 LiFe flight battery just under the fore edge of the hatch, one of the sound systems transducers, and 4oz of weight in the cowl. Balanced it at 110mm and it flies wonderfully. 100mm CG was waaaayyyyy too nose heavy on its first flight.

[Sky King]

I've got the V2 also. Flew it at 100mm first flight with half up elevator . Sort of landed crashed with 1/3 power. A new wing later I've settled on 110mm with the gear tucked up. With a 4000 Admiral and 4oz of lead in the nose cowl its ready for Spring and flite 2.