I finally got my Giles 202 in the air the other day. I installed a Magnum61 4 stroke motor (new) and built it seemingly straight.
The only thing i deviated from on the plan was the CG. It specified 85-95mm (from memory) back from the leading edge. I think mine was about 15mm further back than that and I didnt think it would make much of a difference.

With the engine fired up, it took ages to get off the ground. Also when maintaining straight and level flight, it seemed to be "bobbing" and wobbling around the sky. Turning resulted in losing a lot of height and the plane seemed to struggle to regain altitude. I got as much speed up as possible and tried a loop - it snapped to the left! I had never had a plane do that before. What causes the snap? is it tip stall? warped flying surface? lack of airspeed?

Anyhow, landing was just ok but took more concentration than what I would have thought acceptable.

So now i have removed the Magnum. I am installing a OS46FX which i HOPE will be a little more responsive. Also, i weighed both motors and the OS is a little heavier than the Magnum - this should help with the CG. I am also relocating the battery to under the tank (I had to cut the film off the front just behind the firewall and will make a ply plate to screw in place. I am also moving the servos right to behind the tank. Incidentally, i bought a sullivan 8oz flexitank and it fits in PERFECTLY; not cutting or dremelling required.

I hope this will help the plane fly a little better - at least it couldnt be any worse!!

mike

all replies and suggestions gratefully received!