ORIGINAL: outdoorhunting
GP Extra 300S (60) kit.I put a "90" Super Tigre in it ( notice the statement at bottom of post). I worked 1/2 a day trying to balance it inverted. It wouldn't balance right. I could get it almost perfect (14oz. lead in the nose) & it would either slowly start drifting down or up on the balance machine. I finally turned it upright to try it & it took 3/4 oz. to get slightly nose heavy. I flew it & it seemed to be a little "tail heavy" It's all for naught as about 2 mins into maiden it "tip stalled" & augered. The plane was totaled. Although, I hate it that I wrecked it, it would be nice to know for future reference.
I put a repaired plane back in the air about two weeks back. White knuckles and I was astonded that I got it down in one piece. It was tail heavy to th extreem. I re-caculated the CG and found I needed 9 oz up front to balance it you. Ifabercated a huge weight and bolted it under the engnine. Well It flew OK, none of the wild pitching from the first flight, but it took about 3/4 down to hold it level when Inverted. Obviously 9 oz was to much. I drilled out an ounce when I got home and the next fly day, things were better, but still a tad nose heavy. More drilling, better but not quite there yet. I then pulled the remainder of and moved the engine ahead the length of th mounting lugs. Better but still not there. I moved the engine back and fabed up some lead sheet and by now, I was down to 2oz. I could now pull off weight at the field with little effort and today, It was just about as good as you could get. Very slight down to hold it level when inverted, actually almonst none. Inow am right back to the balance I initally started with that was "way tail heavy". I think I was just letting the adrenillan take over and was over sticking the plane on the first flight. If flys very well now. Nothing moved nothing added, and nothing taken away.
After all the ribbing about the boat anchor I put on for weight, I was a little red faced telling the guys what I found.
Just a work of advise, first flight should be noticably nose heavey. It may not fly the best, but you will get it back down and can work your way down to the correct banlance.
Don