Resolution

[John Petterson]

Jeff, I think he is comparing using ATV to making the mechanical adjustment
to allow full travel on the servo to move the control surface the same
distance. Wayne, you are right that you are losing some power by using ATV
instead of changing the linkage. But changing the ATV should not change the
power of the servo - it is just that you lose some mechanical advantage of
having the control linkage closer to the control surface (need less travel
for the same surface deflection) so the net is less push available. And the
percentage should be approximately equal to the ATV percentage reduction.

Did that help or just confuse the issue more?

John

-----Original Message-----
From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org] On
Behalf Of Jeff Hughes
Sent: Wednesday, October 06, 2004 8:58 PM
To: discussion at nsrca.org
Subject: Re: Resolution

But, the work load is less, because the aileron movement is 25% less.

----- Original Message ----- 
From: "Tom Simes" <nsrca at shinymetalass.com>
To: <discussion at nsrca.org>
Sent: Wednesday, October 06, 2004 7:10 PM
Subject: Re: Resolution


> On Wed, 6 Oct 2004 15:08:03 -0500
> "Wayne Galligan" <wgalligan at goodsonacura.com> wrote:
>
>> A good question at this point would be.
>>
>> How much does the percentage of throw or ATV have an effect on total
>> power output of the servo?
>>
>> Like IF I use 75% ATV to achieve the throw I need.  How much effect
>> does that have on the total power output of my servo?
>>
>> Wayne G.
>
> Correct me - gently ;-) if I'm wrong, but I believe this simplifies to a
> lever problem and using 75% ATV increases the force required of the
> servo by 33%.
>
> Work = Force x Distance
>
> Moving a control surface through a distance requires a certain amount of
> work.  The control surface could care less whether that amount of
> work is the product of a large force and a small distance or a small
> force and a large distance.  However, obviously your servo and battery
> pack care and would prefer to exert a smaller force over a larger
> distance.
>
> Back to the equation, if we presume linkage losses to be a (hopefully
> small) constant, then the work done on the surface equals the work done
> by the servo.  If work is constant and distance is multiplied by 0.75
> (75% ATV), then force must be multiplied by 1/.75 (133%) to preserve the
> equality of the equation.
>
> -- 
> Tom
>
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