If you use a single wire run to a Smart-Fly equalizer, then connect the servos to the equalizer, you will have the ability to reverse one servo, and set end points / centers of each servo independently. The equalizer is a good cheap solution (a lot less $$ than a Matchox). Unfortunately, if you are using two channels to the elevator servos you will never be able to get an accurate EPA with the radio because once you mix the channels, the ATV settings (and therefore end points) are not equal between channels.

The best solution is to remove the 2-channel mixing and go with the equalizer on a singel channel (ELEV), then adjust EPA and center on each servo independently using the method in my article. Once you have this done, when you move the sub trim, both surfaces will move the same amount and you will not lose symmetry.


There are of course, other ways to do it, but for me this way works the best. I have always been able to get excellent results using this method and if done right, it works on the first try. Before doing this I used the two-channel method and I always was fighting the sticks correcting trims or had planes that would snap out of high rate maneuvers.

It is amazing how a small differential in the surface movement or center / end point alignment can throw off the entire trim.

DP