[NSRCA-discussion] Servo question

[Ron Van Putte]

A few years ago I was walking behind my airplane as it taxied out to  
the runway.  I got a little too close and touched the bottom of the  
left aileron as I was striding forward.  The aileron moved up and  
stayed there.  No gear teeth were broken.  I recentered the servo,  
using a jeweler's screwdriver, as Jon Lowe described.

Ron VP

On Jul 5, 2008, at 7:07 PM, chris moon wrote:

> Hi Ed:
> That was my first thought that I activated or changed some mixing,  
> but I could not find any difference by moving switches and went in  
> and checked all of my mix settings.  I think now that it must have  
> been bumped or jarred somehow to change the pot setting or else  
> cause some mechanical change in the pressed together parts.  I just  
> assumed though that if you hit the elevator hard enough, the first  
> thing to fail would be one of the tiny plastic servo gear teeth but  
> that might not be true.  Anyways, the servo is on its way to  
> Horizon now and I hope they can find and report what is out of  
> tolerance with the servo now.
>
> Chris
>
> Ed Alt wrote:
>>
>> Chris:
>> Any chance that you didn't disable the lever/knob/switch  
>> associated with the aux channel that you mix the elevator into for  
>> the 2nd elevator servo?
>>
>> Ed
>>
>>
>>
>>
>>
>> From: cjm767driver at hotmail.com
>> To: nsrca-discussion at lists.nsrca.org
>> Date: Sat, 5 Jul 2008 12:47:55 -0500
>> Subject: [NSRCA-discussion] Servo question
>>
>> Ok, here is a brain teaser for you experts.
>>
>> On Sunday 2 weeks ago I went out flying maybe 4-5 flights. All was
>> fine. When I got to the flying site on Friday for the Lake City
>> contest, I made a practice flight and the plane was climbing like  
>> mad.
>> I got it down and found that 1 of the elevator halves was about  
>> 3/8" up
>> from the other. Before the flight, I checked the operation of the
>> elevators and they were moving correctly but I don't remember
>> specifically if I paid any attention to if they were centered
>> perfectly. Now, nothing was changed between the the last time I flew
>> and this flight. The transmitter was on the right model. The linkage
>> had not slipped, nor had the control horn bent. The control surface
>> showed no sign of trauma from a severe bump possibly causing a  
>> stripped
>> gear. The servo (JR 3421sa) was functioning 100% normally it was just
>> the center had changed on it's own. I removed the servo arm (alum  
>> - not
>> stripped either) and moved it one spline and adjusted the sub trim
>> slightly and flew a few test flights and the contest with no  
>> problems.
>> Now at home, I removed the servo to send it back and inspected it and
>> found nothing abnormal. The gears all look fine. Here is what I have
>> eliminated:
>>
>> servo arm - not stripped
>> servo gears - not stripped
>> pushrod and linkage - no play and not slipped on the clevis threads
>> transmitter - correct model selected and could not be elevator pot in
>> transmitter since it did not affect the other elevator servo's  
>> centering
>>
>> I am sending it back for a check up but just was wondering if  
>> anyone has
>> had any similar experience ever or if they have any possible causes.
>>
>> Thanks
>>
>> Chris
>>
>>
>>
>>
>>
>>
>>
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