Rod Bender

Hey Guys,

I maidened a few weeks back, thought I was very close, but while at the field, I let a couple aerobatic pilots test flight the plane. They all said it was nose heavy. I brought the plane home and moved the fuel tank from directly behind the firewall to just in front of the wing tube, its as close to the suggested CG as possible. I also added my 2nd battery pack in the aft cabin space where the 1st one is located.

I took the plane out a few days ago, and oh boy was it tail heavy, or it flew that way. I only did 1 flight like this as it was very dangerous. I brought the plane home, and built a CG stand to use on this, and any future models. The suggested CG on a Funtana 90 is 7 1\8" behind the leading edge. When I checked the CG today with this new CG stand, it balanced at 6 3\4", suggesting that I was still nose heavy. There is NO way I'm going to move or add more weight aft to aquire this suggested CG.

I talked with 1 person from the club that has the same model, and he claimed he had major CG problems with his setup also.

I wanted some input from other Funtana owners on their setup, and if they use the suggested CG, or if they've come up with their own?
At this point, I am opting to just move my internal electronics to aquire the best flight characterisics, with no regard to the suggested CG.

Any and all input greatly appeciated... Thanks, Greg

alan0899

G'day Mate,
Once you have flown your plane, you need to adjust the balance point to YOUR flying style,
the manufacturers, have a recomended starting point, & you need to adjust it from there.
If it seems tail heavy move something forward a bit, but mark where you move the balance point from, & where you move it to, put a marks on the wings, with a felt tip pen, it will wipe off with a bit of methanol when you are finished with it.
That way you can see how the flight characteristics change.

Rod Bender

G'Day Alan,

I agree, and am going to put things where they work for me and this plane. With the last CG I flew at, I had to give it 1\4 down elevator just to bring the planes attitude into a somewhat landing degree, hairy landing. Inverted flights it climbed, everything is indicating tail heavy, yet the specs are telling me to add more [X(]

NOT

..................... Greg

tukkus

My Feedback: (2)

I think I'm at 6 1/4" and it could still go a little more forward.... I orginally set it up at 7" and that was way too tail heavy....it always wanted to climb and landing it was interesting...don't be afraid to go farther forward with it, I'll most likely try 6" and see how that feels once the weather gets better.

I have a YS 110 on it and my 6V battery and 6 ounces of lead are mounted on the engine box for my CG.... I'm thinking of going to a pull-pull so the rudder servo will be closer to the CG, i have hitec 645's on the elevators that weigh a little over 2 ounces and I'm thinking of getting JR 125mg's which will save me another ounce from the tail...it's a little over 9 lbs and if I put it on a diet I should get it down to 8 1/2 lbs and only spend $65-70 for it.

My other option is to mount my YS 140L that weighs 32 ounces and get rid of the dead weight and that will allow me to use the battery to adjust the CG

Rod Bender

Thanks for the comeback Tukkus,

And thank you for the 411. I am hearing from other 90 owners at the club that they have had CG issues as well, they all think the info provided with the kit is wrong, it sure seems like it'd have to be. I'm moving my battery packs forward to just behind the wing tube, and see where that put's my CG. I wonder how many people have built their plane to the factory specs using that CG and stuffed it?

Thanks again, Greg

SeaPlaneSupply

My Feedback: (7)

Hi Guys,
To test the CG while flying, trim plane for staight and level, then climb at 45 degrees, roll inverted. The plane should continue up for 2-3 seconds then slowly start to drop the nose.
When is going to warm up?... it's freezing in Michigan
Mark

rc-sport

My Feedback: (12)

The CG listed in the Funtana 90 is correct for the type of flying it was designed for, 3D. I had one flying at the correct CG and the first flight scared the crap out of me. I moved the CG forward to 6.5" and it was more to my liking, I did get used to it and had fun. That plane urges you to try things you aren't ready to try.