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Old 10-29-2009, 02:13 PM   #52
JoeAirPort
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Join Date: Jan 2006
Location: Milwaukee, WI
Age: 47
Posts: 5,501
Default Re: Elevator Mis-match

Quote: Originally Posted by 3D-Seth
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No.

You will end up with un-equal elevator travel this way. See attached picture that I drew.

Because the servo is below the stab, when the servo turns towards the elevator, the linkage goes straight much quicker. When the servo turns away from the elevator, it has the reverse effect; pulls the linkage away much quicker. This is why it needs to be mounted with the servo arm towards the front of the airplane.

**Note: this is only for fuse mounted elevator servos, not stab mounted elevator servos.

Seth
This is a really good example of what Joe Hunt called the "to be determined center" (from his old DOD site's instructional video). It's "to be determined" by your air frame's servo pocket postions, control horn type..etc. In this case it ended up a few degrees away from the hinge line. If you had the servo pocket higher and the push rod going under the servo, then your "to be determined center" would be in a different place. Possibly towards the hinge line this time. I had an Edge that was like that. People thinking they can do all this in a servo programmer, match box, equalizer, radio etc. had better study up. Because the brothers in this hobby that have figured it out know better (Joe Hunt and others that taught us this...credit to them).
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