I have a full suite of Garmin in my RV14A and just completed the build and now configuring the avionics- in particular the trim direction and related Autopilot movements. I have the roll trim servo in the wing.
This maybe a silly question but I am wondering which way the stick should move (on its own) when I press (say) the right trim button - should the stick move to the right or the left.
Right. But how about elevator trim?
On a panel switch up, would be natural for nose up.
But on a stick, forward is nose down or nose up? I'd think nose down (same way as you push the stick -- but?
Right. But how about elevator trim?
On a panel switch up, would be natural for nose up.
But on a stick, forward is nose down or nose up? I'd think nose down (same way as you push the stick -- but?
Finn
It is your choice as long as it is labeled. With a rocker switch on the panel most people prefer pushing the top for down trim, similar to rolling a "trim wheel" forward. Remember, the elevator tab goes down for "up" trim and up for "down" trim. Believe it or not approximately 1/2 of the airplanes I inspect have at least one trim backwards.
Think of pitch trim like a trim wheel. Either on the stick or panel, the top or forward push of a rocker switch seems to mimic rotating a trim wheel for nose down.
I think of trim as what pressures I want to trim off to maintain level flight.
Elevator: If my nose is wanting to climb I need more nose down pressure to maintain level flight. I trim nose down (forward on the coolie hat trim switch) which in turn pushes the elevator trim tab up - which forces the elevator slightly down thereby lowering the nose of the aircraft to level flight conditions.
Aileron: Think about what happens to the aircraft when you make a turn. For a right turn I push the stick right which pulls the right aileron up (decreasing lift) and pushes the left aileron down (which increases lift).
Now let’s apply this to a situation where my flight today is solo so the right side of the aircraft is lighter than the left side (I’m a full figured guy). The left wing needs to generate a little more lift to compensate for my “heaviness ”. The right wing needs to generate less lift to maintain wings level flight.
So just like a “right turn” I need to move the stick slightly right. My trim setup is wired so that I apply “right turn (trim)” on my coolie hat switch. On my airplane I usually have to apply almost full right trim when flying solo and center the trim switch when flying dual. I burn initially out of the left tank when solo (5 to 10 gallons - depending on fuel load) then transfer to the right tank for the next five gallons then back left again. Airplane flys a really nice ILS with minimal trim changes. Of course as speed decreases and flaps are extended a little “nose up trim” (aft coolie hat trim) is required and nose down (coolie hat forward trim) when a missed approach is initiated and the airplane increases in speed with less drag and greater power application.