Hi Ace,

Why do you think that's a problem? The trim is what it is. There is no rule that says the elevator must be lined up with the horizontal stabiliser (I presume this is what you are seeing as wrong ?).

There are some theoretical advantages in having it faired, but these are only minor drag effects. A pylon racer might be interested in it or a full size designer looking for best possible range, but we would never notice any difference in a model Pitts (nice model BTW, I had a quick glance at your build thread).

Try flying your model at a low cruise speed and trim out the elevator. You will notice it's no longer 4° down, it might even be aligned with the stab now, or it might even be up a small amount. It depends how slow a speed you trimmed for. So the trim is speed dependant, the faster you go the more down trim is required. This effect is more noticeable with a forward balance point. Do you have a lot of power? If so you may be cruising faster than the designer designed for. Again more down trim would be required.

If it really worries you then the best fix would be to cut out the horizontal stab and shim up the leading edge a degree or two, you might be lucky enough to guess it just right so that the elevator now fairs with the stab. Now the whole elevator and stab are making the same lift as the 4° deflected elevator was before but with maybe very slightly less drag. Seems like a lot of work to end up with the same trim but elevator faired.

You could move the balance point forward, which would require less down trim, but the aeroplane would fly a lot worse. More elevator deflection required for the same pitch response, more drag, more likely to nose over on landing, heavier model unless you can move stuff forward, more down elevator required when inverted etc.

Some down thrust would help, and might be a good idea if you are getting a lot of pitch up as speed increases due to forward balance point. (moving balance point aft might be better in this case though).

Reducing the wing rigging angle would also require less down trim. This affects the thrust angle as well though. Let's assume for arguments sake that your wings fly at 1° nose up at your normal cruise speed this means that your fuselage and engine are 1/2° nose down (wings are rigged 1 1/2° nose up right?). If you reduce the rigging angle to zero you will need up (less down) elevator to get the wings back to the flying angle of 1° nose up. The fuselage and thrust angle will now also be 1° nose up unless you increase down thrust by the same 1 1/2°.

If It was me I would concentrate on adjusting the balance point and control throws, mixes, expo, and trim to get the model flying the way I like it. Then, after parking it, give full down elevator before turning the receiver off. That way the elevators would look scale hanging down like they do on a parked Pitts and no one would know what the trim setting was.

Hope this helps,

Dave H