Hi there.
Just a simple question.
When we are ready for maiden--->trimming of a new plane,
we trim it at full throttle or mid-throttle?

I am sure there is a correct answer for this but... I trim my planes based on airspeed. It's a feel not a number. I get a feel for my plane at the different speeds and say hmm thats about my cruise speed for the downwind leg and set the trims for "hands off" level flight right there. I say it's your model so trim it for YOU.

G'day Mate,
It really depends on what sort of plane it is, a pattern type aircraft, should fly the same when trimmed for full power as it does for 1/2 power, BUT a trainer is usually trimmed for straight & level flight at around 1/2 throttle, so that adding power will induce a slight climb, very helpful while learning landing approaches. So it all depends on the plane in question.
What sort of plane are we referring to here Kostas?

My problem with trimming is really how to determine if it is the rudder or the ailerons that need adjustments when my TRAINER is not heading straight
any tips?

No problem with up and down , I know how to trip for that!!

G'day Mate,
Check your rudder, on the ground, it should be in a straight line with you fin, adjust to make it so, then when in the air, trim your ailerons for straight flight, at around 1/2 throttle, if this trim changes as you change speed, either faster or slower, then you may have a warp in your wings. Also if your trim changes as you slow down, or speed up & you have checked your wings & found no warps, you may have a heavy wing on one side, check this as well.
But the best way is to get an experienced flyer to help with your trim, not necessarily trim it for you, but advise you as you trim.

Thanks
I thought the rudder fin could be warped also and not visually spotted at the beginning!

SuperSportster 40 and Do 46!