gyro
GSN Contributor
Aerobeez 90" Extra 330SC (50cc)
I'm sorry D-Man, I've never measured the CG on my giant scale planes. I've found that the CG range is so forgiving from tail heavy to nose heavy... That I just build it the way I think it needs, then fly it and move things around afterwards if necessary.
I always measure CG in flight by checking the nose on a 2/3rd power, inverted up-line, and adjust based on that. I find that the way it feels to me in the air is a better measurement than what a balancer gives me, and it's also very subjective!! I like a neutral balance on most planes, but some fly better slightly nose heavy.... So it all really depends on your taste and each planes flight characteristics.
For example, in the video of Brian flying we posted last week, it was before we added the 4oz and moved the rx batteries further forward... And it was definitely tail heavy, but still flew well, just not to my personal taste.
The problem with the electric setup, is much of the weight is in the batteries, and due to the construction of this plane, it isn't possible to get them as far forward as they need to be using traditional straps... This is why we needed to add weight. I don't think this will be an issue with the gas setup, as nearly all the weight is up at/in front of the firewall.
My guess is the plane will be about 16 - 16.75 lbs or so, and I think it will balance just fine. The engine installation is progressing and I expect it'll fly next weekend. We're installing the gear forward with a full size throttle servo just behind the firewall, 16oz fuel tank resting in front of the wing tube, and the rx packs forward like in the electric setup. It'll be easy to move them back if necessary after checking the plane in flight.
Once I get the plane balanced to my taste, I'll do my best to get an actual measurement for you.
I'm sorry D-Man, I've never measured the CG on my giant scale planes. I've found that the CG range is so forgiving from tail heavy to nose heavy... That I just build it the way I think it needs, then fly it and move things around afterwards if necessary.
I always measure CG in flight by checking the nose on a 2/3rd power, inverted up-line, and adjust based on that. I find that the way it feels to me in the air is a better measurement than what a balancer gives me, and it's also very subjective!! I like a neutral balance on most planes, but some fly better slightly nose heavy.... So it all really depends on your taste and each planes flight characteristics.
For example, in the video of Brian flying we posted last week, it was before we added the 4oz and moved the rx batteries further forward... And it was definitely tail heavy, but still flew well, just not to my personal taste.
The problem with the electric setup, is much of the weight is in the batteries, and due to the construction of this plane, it isn't possible to get them as far forward as they need to be using traditional straps... This is why we needed to add weight. I don't think this will be an issue with the gas setup, as nearly all the weight is up at/in front of the firewall.
My guess is the plane will be about 16 - 16.75 lbs or so, and I think it will balance just fine. The engine installation is progressing and I expect it'll fly next weekend. We're installing the gear forward with a full size throttle servo just behind the firewall, 16oz fuel tank resting in front of the wing tube, and the rx packs forward like in the electric setup. It'll be easy to move them back if necessary after checking the plane in flight.
Once I get the plane balanced to my taste, I'll do my best to get an actual measurement for you.
