G'day John,

Here's how I trim out a new model, and it's about the same as BMatthews and the others are telling you here.

First get the balance right;

Fly straight and level at 3/4 throttle or so and use the radio elevator trim so it will fly hands off. Leave the trim where it is for the next three tests.

Get some height and dive at 45 degrees and let go. If the model rapidly pitches up it's nose heavy, if it slowly pitches up it's about right, if it stays nose down or dives further it's tail heavy.

Fly level with the power as above and roll inverted. If you need a lot of down elevator to fly level inverted it's nose heavy. Not much down elevator, it's about right. No down elevator required, could be tail heavy.

Power as before, pull up to 45 degrees and roll inverted then hands off. If it pitches rapidly toward the horizon it's nose heavy. Slowly toward the horizon, about right. Continues up at 45, tail heavy.

Change the balance, fly and retrim the elevator with radio, then repeat as required.

Next get the elevator response right;

If after adjusting the balance the model flies heavy with insufficient elevator authority to stall and spin, loop, bunt, flare for landing or rotate for takeoff, increase the elevator throw.

If the model is twitchy and there is more than enough authority ie it stalls with small elevator inputs, stalls out of loops and bunts, is easy to over rotate on takeoff and landing. Reduce elevator throw.

If the elevator authority is good but the model is still a bit twitchy, add exponential to the elevator.

Now set down thrust;

Fly straight and level power as before, trim elevator with radio for hands off. Open throttle to full and observe the model response.

Nose rapidly rises, model speed may reduce. Adjust thrust line down.

Nose gently rises, speed reasonably constant. Thrust line about right.

Nose stays level or drops, speed increases. Adjust thrustline up.

Repeat the test but this time close the throttle.

Nose stays level or climbs, speed drops adjust thrust up.

Nose drops gently into a glide, speed drops a bit. Thrust about right.

Nose drops badly and speed increases. Adjust thrust down.

Once you are happy with all these adjustments fly the model and set the elevator trim with radio, land and check the elevator position.

If the elevator is faired with the tail plane or close. Great, adjust your linkage so that you can return the radio trim to neutral.

If the elevator is deflectd a fair amount. Also leave it alone unless you could use a bit more authority in the direction it is deflected or if you are pylon racing (the drag is almost insignificant, you would be better of spending your time reducing drag elsewhere).

If the elevator is deflected a large amount or if you really have to have it faired adjust the incidence either tail plane or wing. Be aware that in your case if you adjust the wing you will be adjusting the thrust at the same time because the engines are mounted on the wing.

Don't adjust incidence until you have everything else to your liking.

There's more to it if you are seriously into aerobatics but this will get you close for sport and scale flying. It's a bit of individual feel thing to, set the model up to where you like it.

How did you get on with water spray and prop clearance? Was I right about it being OK?

Lovely looking model and looks like a great site for flying.

Dave H