Hi Si I had the same problem as your having with the trim, I had a big crash from about 40ft up, all I had left was the main unit. I upgraded with the lloy bits to. When I came to test fly the heli I found I coundn't trim it up, what I found was if you set the alaron and elevator trim to center, then adjust the servo linkage arms until the heli is near enough trimmed then fine trim it on the TX. I also found I had to adjust the gain and proportional pots, this is done a tiny bit at a time, don't forget to re-arm the heli when you make any adjusments to the pots. Hope this helps Chris.