I had my first flight with my new GP .20 J-3 Cub on Friday. I set up the high and low rates according to the instruction manual.

It is not possible to do a nice 3-point landing. Even with full up elevator on high rates it touches down on the main wheels (well above stall speed). The tail won't come down before the main wheels are on the ground. I have checked the CG, and it is correct.

I see two solutions to this.
1) More elevator throw
2) Move the CG aft

I had the same problem with my 4*40, and moving the CG aft solved it. The plane became "snappier" and it was possible to go all the way down to stall speed in level flight. I have to keep an eye on approach speed and not let it go too slow, but the plane is not difficult to fly with the CG a little behind the recommended location.

Another thing is that the 4*40 now needs less trim when going from low to high speed and vice versa. How come? I think it might be because, with the aft CG, the tail drops a little at low speed, increasing the wing's angle of attack and producing more lift => no up trim required. Is this the explanation?

I read that one way to see if the CG is right is to roll the plane 90 degrees and see if the nose or tail drops. I tried it, and the nose dropped a little. This would indicate that the CG is a bit too far forward...?

I know that the simple solution is to use more elevator throw, but it seems strange to me that the plane is impossible to stall from level flight. So I want to find out what the problem is and correct it. I don't think the plane flies the way it is supposed to.

Any comments/advice appreciated
Thanks!

-Tore