Originally Posted by yarrumevets
I had an "adventurous" maiden today.
I got my Beaver second-hand from our RC Flying Club ex-president as an airframe and servos configuration. I put my own 32-equivalent motor in it, along with a 60A ESC but the problem was batteries - only had some 2200 mAh 3S handy, which were delivering plenty of power with a 3-blade 12x8 prop and the static tests were good, showing a little over 400W. Of course, the issue was they weigh less than the recommended 3200 mAh specimens. I was keen to fly it, so I tolerated the insult of taping some lead to the underside of the cowl until I could get some batteries of the correct capacity (i.e. weight). I checked the CoG three times but it seems I need to do it again because after a smooth take-off she stood on her tail at an altitude of about 40 feet. I got the nose over and reduced the throttle a little and things improved to the point that I considered it was "all good". It wasn't though, because she was only happy flying in a straight line - the slightest bank resulted in a dropped tail and then a wing, so I cut the flight short immediately and got her down for a less-than-graceful touchdown.
I could see from the short time aloft that it will be a really nice bird to fly as soon as I get my act together and get her balanced properly. I've got some 4S batteries which I will now use instead and I expect things to improve considerably.
Interesting, as I use 3s 2200's. You should be able to balance out just fine, provided you're using two packs in parallel. Then you wouldn't need the lead, and would get nice long flight times. I *think* if you just use one 4s batt, you'll run into the same tail-heavy tendencies, unless it's 3200mAh or larger. Can say for sure though, as I only run 2 packs (either 3s or 4s) in parallel, and it balances great either way. Best of luck in your next flight - let us all know how it goes...