[NSRCA-discussion] SD-10

[Anthony Frackowiak]

I am pretty sure it is the resolution. Keep in mind that most  
installations are not using the full throw of the electronics. So you  
are using some percentage of either 1024 or 2048.

All I know is what I felt when I changed. 2048 was a definite  
improvement and is why almost all the top systems have gone to it.

As for a 3D heli VS a jet, jets were not what was used in the AFTPS  
test. Keep in mind that the people involved in that test were highly  
educated and trained test pilots and engineers. So I sort of trust  
their judgement!

Tony


On Aug 24, 2009, at 4:17 PM, Atwood, Mark wrote:

> Do you really think its the improvement in resolution and not the  
> improvement in speed between the two systems?  I'm sure I don't have  
> tight enough linkages to take advantage of 2048. I'm not sure  
> they're tight enough to detect 1024. That would require less than . 
> 001" slop.   .0005" for 2048.
>
> I pushed hard for 2048 because of all the "buzz" but after doing the  
> math realized that no other part of my equipment has that level of  
> accuracy.  To be fair, I don't run the MK ball bearing  linkages  
> though.
>
> I'm inclined to agree that were getting speed in excess of our  
> ability to discern, though I'm guessing that the responsiveness of a  
> full scale jet is less than that of a 3D Heli.
>
> I think a LOT of this is similar to the old distortion specs for  
> stereo equipment prior to CDs.  Early CD players would boast signal  
> to noise ratio's better than their competition even though even the  
> cheapest units far exceeded the level of human hearing.
>
>
> --------------------------
> Sent from my BlackBerry Wireless Handheld
>
>
> ----- Original Message -----
> From: nsrca-discussion-bounces at lists.nsrca.org <nsrca-discussion-bounces at lists.nsrca.org 
> >
> To: General pattern discussion <nsrca-discussion at lists.nsrca.org>
> Sent: Mon Aug 24 18:22:03 2009
> Subject: Re: [NSRCA-discussion] SD-10
>
> Just for general info, when I was working at NASA a few years back I
> did a test with the Air Force Test Pilot School that studied latency
> in control systems. They found in their simulation tests that anything
> faster then about 40-50 ms was not noticed by the pilot. Resolution
> was not studied in that test, but I sure felt a difference when I went
> from a 10X with 1024 to a 12X with 2048. Just another opinion!
>
> Tony
>
>
> On Aug 24, 2009, at 1:18 PM, Atwood, Mark wrote:
>
>> I'll take a stab, and I'm blind copying Mike Greensheilds (don't
>> feel comfortable putting his email out on the list) who is the
>> product manager for ATX here in the states.  He may chime in with
>> additional background.
>>
>> My understanding is that when Sanwa was evaluating speed vs
>> resolution, speed was deemed a much more critical factor.  1024
>> resolution is already to the limits of our ability to "feel" any
>> difference where as the speed/latency was much more noticable.
>> Cost does come into the equation such that for a $500 radio, they
>> couldn't do both.
>>
>> 1024 resolution provides better than 1/10deg at 90 deg of rotation.
>> That's less than 1/1000" on a 1" servo wheel.
>>
>> The speed on the other hand is just now approaching our limits of
>> "feel".   The faster systems clearly feel more connected and are
>> noticable when flying Snaps and other rapid input maneuvers and
>> especially flying 3D with the helis.
>>
>> So the choice was to invest in a fast response system with 1024
>> resolution.
>>
>> Does anyone know the tolerances of our servo accuracy?  I'd be
>> curious to know how high a resolution they can accurately replicate.
>>
>> Mike?  Any input from the source?
>>
>> -Mark
>> --------------------------
>> Sent from my BlackBerry Wireless Handheld
>>
>>
>> ----- Original Message -----
>> From: nsrca-discussion-bounces at lists.nsrca.org <nsrca-discussion-bounces at lists.nsrca.org
>>>
>> To: 'General pattern discussion' <nsrca-discussion at lists.nsrca.org>
>> Sent: Mon Aug 24 15:30:03 2009
>> Subject: [NSRCA-discussion] SD-10
>>
>> Hi Anthony, Jim, Mark , and Others who Responded,
>>
>>
>>
>> Thanks for your valuable input. I’ve read that this radio’s
>> resolution is or is among the very  fastest; so much so that even
>> digital servos can’t keep up with it. I understand  that the system
>> is 1024 , but can’t help but  wonder why it isn’t 2048. I’m sure
>> I’ll get past my  hangup, but would appreciate everyone’s insight’s
>> on that one.
>>
>>
>>
>> Thanks,
>>
>> Frank Imbriaco
>>
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