[NSRCA-discussion] Aileron servo arm size and resolution?

[Kelly Regan]

Dave and Fred,

Just a little more info on how I try and set up the planes...

I always adjust the linkages so I have near zero sub trim and 0
radio trim.   I always try to give the servo's the best mechanical
advantage possible and still get the throw I need.

I have read the trimming guide published by Peter Goldsmith in the
AMA mag last year and try to follow that when setting up my planes.

I was at almost the full servo throw - 45 degree's on the ailerons.  If
I go to the outside hole of the round wheel that should give me aprox.
35 degree rotation in each direction. that will give me some room
for a higher rate condition for snap, spins if I need it.


 
Dave Lockhart wrote:
> Kelly,
>
> Without going into default and max/min values for each parameter for each
> brand radio, endpoints, ATV, AFR, dual rates, mixers (built in, or Pmixes,
> or differential mixes), and trim all have an effect on the amount of servo
> travel.  You will have max servo resolution when the servo moves through the
> full range of available travel (typically 90 degrees, 45 degrees each
> direction).
>
> The setup is a compromise between "speed" and resolution.  Move the linkage
> out on the servo and reset the servo throw to yield the same control surface
> deflection, and the resolution has gone down and the time needed for the
> control surface to reach max deflection has also gone down.
>
> So, if your flying rates have 45 degrees of servo rotation in each
> direction, you are at max resolution.  In practice, if your servos are
> moving 30-35 degrees in each direction, you will be in pretty good shape,
> and you have some servo throw "leftover" to accommodate trim, sub trims, and
> mixers.
>
> Dave 
>
> -----Original Message-----
> From: nsrca-discussion-bounces at lists.nsrca.org
> [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Kelly Regan
> Sent: Wednesday, January 03, 2007 10:27 PM
> To: NSRCA Mailing List
> Subject: Re: [NSRCA-discussion] Aileron servo arm size and resolution?
>
> I forgot to add that I am running 6.0 volts with a
> 7.2 volt li-ion pack and Fromco regulator.
>
> Fred, can you explain or give me an example of what you
> mean by bad control system?
>
> I have been trying to understand the affects of high atv's and resolution
> for a long time and the information I find is conflicting.
>
> At what point do you realize full resolution?  100% ATV and 100%
> on the duel rate screen?   Is there an advantage in going to 130% ATV
> as far as resolution is concerned?
>
>  
>
>   
>> You should get your full surface travel (high rate) as close to 100% ATV 
>> setting as possible.  ATV is a trap and if abused can lead to some really 
>> bad control system installations.
>>
>> FHH
>> ----- Original Message ----- 
>> From: "Kelly Regan" <kelly.regan2 at verizon.net>
>> To: <NSRCA-discussion at lists.nsrca.org>
>> Sent: Wednesday, January 03, 2007 8:14 PM
>> Subject: [NSRCA-discussion] Aileron servo arm size and resolution?
>>
>>
>>   
>>     
>>> What length servo arms do you run on the ailerons?
>>>
>>> Why do I ask....
>>>
>>> When I first set up my Brio with the 9411 sa's on the ailerons
>>> I wanted to make sure I had full servo/radio resolution.
>>>
>>> I fly with a Futaba 9C and have CHP control arms on the ailerons.
>>>
>>> I set my ATV or End Point in the 9C to 130.  I used a standard JR
>>> servo wheel with the linkage set to the inner most hole.  In order to
>>> get the 1/2" aileron travel per the Brio manual I ended up with 120%
>>> duel rate.  It was my understanding that this is exactly what I wanted.
>>> High ATV and high duel rate for full resolution?
>>>
>>> When Don flew my plane he said the aileron servo's seemed slow
>>> to him?  He was surprised to hear I had 9411sa's.    He suggested
>>> that I use longer servo arms and reduce the ATV to 100% to make
>>> the to keep the throw at 1/2" while increasing the surface speed.
>>>
>>> Tonight I installed the shortest Dubro arms with the linkage on the inner
>>> most hole.   That put the numbers at 100% ATV but I had to reduce
>>> the duel rate way down to 50% to get the same 1/2" throw.
>>>
>>> Am I wrong in assuming that cuts my resolution in half?
>>>
>>> I wanted to get you opinions on since I am now totally confused.
>>>
>>> What does a faster aileron speed do for me versus the loss of resolution?
>>> What is an acceptable loss in resolution to gain the speed?
>>>
>>> Thanks for you help
>>>
>>> -- 
>>> ______________________________________________
>>>
>>> Kelly Regan
>>> www.reganbrothers.com
>>> Home Page: http://mysite.verizon.net/vze6uror/
>>> ______________________________________________
>>>
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>>> NSRCA-discussion at lists.nsrca.org
>>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>>>
>>>
>>>
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>>   
>>     
>
>   

-- 
______________________________________________

Kelly Regan
www.reganbrothers.com
Home Page: http://mysite.verizon.net/vze6uror/
______________________________________________