Do the bind inverted using the polystyrene brace from the box on a level surface
For flight switch the TX on, then the model.. then place the model down on some flat ground and wait for it to sort itself out..
Trimming is done in as3x mode, not safe... I adjust the push rod bends to raise both elevons by a tiny amount, I set mine with them raised by the thickness of the wing at the trailing edge..
With it set like that mine flies fine.. battery just stuffed anywhere in the nose.
I think its angle at bind affects its level flight so its worth rebinding, inverted, with the rear end raised a touch, so when its the correct way up the nose has effectively been raised and trying again..
Mine was going down at launch, not flat, this was initially sorted with TX trim.. and later rebinding.
As you can see from the video it was still going down slightly when the power/throttle was set lower, on the first launch.. but when the power was set higher it remained flat.. this was a nose heavy flight.. note the first launch was downwind, and this also makes a big difference....lol
Both mine are balanced 1/16" ahead of those holes and fly perfect upright, inverted and everywhere inbetween, even in howling wind. If it's too nose heavy inverted requires too much down elevator.
Finger tips are not very accurate on tiny models. I use two short lengths of bamboo skewer that are rounder off and held in a vice.
I use 500 and 650 batteries with the mounting location marked inside the fuse. The 500 mounted as shown in the instructions and the 650 towards the rear with the use of velcro.
A few CG silly millimeters make a HUGE difference in this tiny wonder.
Also, made sure the elevon TE match the wing using the wire pushrod 'U' as the reflex seems to be built into the airfoil.