aileron servo instl vs vibration

[Jerry Budd]

True.

If Tony hadn't gone electric that was going to be the next technique 
he was going to try.  Based on his experience with turbines, he 
didn't see the need to try it on the ePartner.

Jerry


>Jerry,
>     If such is the case, wouldn't static balancing the ailerons for 
>no load relieve this ?
>Is Tony's plane set up like this ?
>Thanks,
>Paul
>----- Original Message -----
>From: "Jerry Budd" <jbudd at QNET.COM>
>To: <discussion at nsrca.org>
>Sent: Saturday, February 21, 2004 11:11 AM
>Subject: Re: aileron servo instl vs vibration
>
>
>>  Hi Xavier,
>>
>>  A while back Dave von Linsowe tried side mounting the aileron servos
>>  to see if the servo pots would be more tolerant of the motor
>>  vibration.
>>
>>  The theory was that the rotary acceleration forces induced by the
>>  motor on the airframe translate into increased vertical acceleration
>>  at the aileron servos causing the pot wiper preload to vary
>>  cyclically, resulting in increased rate of wear.  It was hoped that
>>  the pot wear could be reduced or eliminated by orienting the plane of
>>  rotation of the pot wiper in the vertical axis.
>>
>>  It didn't help.  Tony Frackowiak also tried it on his Gator G-202 and
>>  it didn't work there either.
>>
>>  And that makes sense, as the pot wiper preload is not likely to be
>>  affected by the inertial forces acting on the very low mass of the
>>  pot wiper.
>>
>>  The current thought is that the inertial forces acting on the
>>  ailerons are back fed into the aileron servo gear train causing the
>>  aileron servos to have to work almost constantly to resist the
>>  uncommanded movement.  The servo moves slightly (but nearly
>>  continuously) around the commanded position to resist causing
>>  excessive wear on the pot and gears (similar to servo buzz).  Since
>>  the servo spends most of its time around neutral, that's where most
>>  of the wear occurs.
>>
>>  Interestingly, the ePartner Tony Frackowiak is flying shows no
>>  aileron servo pot wear through ~40 flights (go figure!).
>>
>>  Jerry
>>
>>
>>  >Is there a prefered method to install the aileron servos and protect them
>>  >from the high level of vibration someone was mentioning?
>>  >Could the servo be mounted on his side with the arm parralele to the ribs
>>  >wihout risking more wear of the gear ?
>>  >I suppose the vibration on the wing servo is mainly up-down
>>  >
>>  >Thanks
>>  >
>>  >Xavier
>>
>>  --
>>  ___________
>>  Jerry Budd
>>  mailto:jbudd at qnet.com
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>>
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-- 
___________
Jerry Budd
mailto:jbudd at qnet.com
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