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Yes there is Jim... Have you looked at the volt meter that Gordon made for me?... it'll<BR>
do exactly what you are asking. You can also test your servos with it. He has a website...<BR>
I can't remember the site address right off hand.<BR>
<BR>
<BR>
Rex<BR> <BR>> From: jnhiller@earthlink.net<BR>> To: nsrca-discussion@lists.nsrca.org<BR>> Date: Tue, 25 Aug 2009 09:47:27 -0700<BR>> Subject: Re: [NSRCA-discussion] SD-10<BR>> <BR>> A big thank you to all for this discussion. About a week ago I solicited<BR>> input on a Futaba system and it was suggested that I also consider the<BR>> SD-10. I was hoping for more discussion at the time.<BR>> I looked at an SD-10 in the local hobby shop yesterday and the price is very<BR>> hard to walk away from and it fit my hands nicely.<BR>> My thumb resolution isn't what it once was and will likely get worse but I'm<BR>> now becoming more aware of 'bounce-back' and poor centering likely due to<BR>> worn (non-BB) stick assemblies and cheap servos.<BR>> The TX stick assembly centering detents that I've looked at in the past have<BR>> a spring loaded bar against a flat spot on a round shaft. I've never felt<BR>> that this offered accurate repeatability for very long. Have there been<BR>> improvements or changes to mechanical stick centering?<BR>> In the old days I remember a test device that could be plugged into the<BR>> receiver that displayed the count relative to stick movement, which was<BR>> useful for understanding centering repeatability. Am I dreaming or did such<BR>> a device really exist? Is there something available now?<BR>> Jim H<BR>> <BR>> -----Original Message-----<BR>> From: nsrca-discussion-bounces@lists.nsrca.org<BR>> [mailto:nsrca-discussion-bounces@lists.nsrca.org]On Behalf Of Atwood, Mark<BR>> Sent: Tuesday, August 25, 2009 6:59 AM<BR>> To: General pattern discussion<BR>> Subject: Re: [NSRCA-discussion] SD-10<BR>> <BR>> Hey Tony,<BR>> <BR>> I don't disagree with your math or understanding, though I'm trying to make<BR>> a slightly different point I think. I also misspoke in a previous post<BR>> regarding how the resolution and EPA settings interact, you're explanation<BR>> is clearer and is also my understanding.<BR>> <BR>> I also want to state that I'm not advocating that 2048 isn't "better". The<BR>> original question was "Why didn't ATX choose 2048 over 1024" and the answer<BR>> from their end was cost and the "opinion" that given the cost choice between<BR>> speed and resolution, that speed had a more noticeable impact on most<BR>> setups.<BR>> <BR>> The point I want to express is analogous to making your house more secure by<BR>> putting 4 giant deadbolt locks...on a hollow core door. You're only as safe<BR>> as your weakest point of entry. Be it kicking through the door or breaking a<BR>> window...the locks are more than adequate and no longer the weak point in<BR>> the system. I believe the same is true for resolution, it's no longer the<BR>> weak point in the system.<BR>> <BR>> To follow your math/understanding, the "step" size for a given resolution is<BR>> constant. So in your max travel example, which I think is a good one, we're<BR>> probably talking about spreading 1024/2048 across 135 degrees of throw at<BR>> max. Thus the "step" size for 2048 is approx 1/15 of a degree, and<BR>> therefore at 1024 it's approx 1/7th of a degree. Regardless of how you dial<BR>> down your rates, that will always be the smallest step size. I.e. if you<BR>> reduce rates as you suggested, reducing EPA to 100% from 150% (down to<BR>> 90degrees) and D/R down to 80% from 100% (down to 72degrees of rotation) we<BR>> now have 1080 pts across 72degrees with 2048, or 540 pts across 72degrees<BR>> with 1024. In Both cases the step size is still 1/15 of a degree or 1/7th<BR>> respectively.<BR>> <BR>> My assertion is simply that 1/7th of a degree of resolution (approx .0012"<BR>> movement on a 1" servo wheel) is smaller than other area's of inaccuracy in<BR>> our setups. Or at least in most people's setups. Getting a setup tighter<BR>> than that is hard. Keeping it there is even harder. Servo gear trains have<BR>> slop, ball links, clevises (big slop), wing adjusters, even the wing tube<BR>> all allow for movement in micro amounts that ruin our accuracy at a given<BR>> point. And I won't even mention the variance in deflection if you're flying<BR>> glow due to vibration which I'm sure makes this whole conversation moot. (I<BR>> know I know...I need to convert to Electric...you keep telling me! I'm<BR>> working on it!).<BR>> <BR>> Anyhow, I hope you understand my perspective. People are choosing where best<BR>> to spend their money to gain the most functionality and advantage in their<BR>> flying setups, and in a similar fashion Airtronics did the same. They felt<BR>> they were giving the pilot the best bang for the buck by choosing speed over<BR>> resolution. I DO think when they complete their flagship radio (a ways out)<BR>> it will likely be 2048 so as to be comparable with the other top of the line<BR>> systems. I'm also pretty sure it won't be $500 though.<BR>> <BR>> This has been a great discussion though and hopefully enlightening to some.<BR>> I did not mean for it to be a brand war on features though as clearly I have<BR>> bias as an Airtronics pilot. I just wanted to try and answer the question.<BR>> I'm happy to discuss further off list, or answer other specific questions on<BR>> or off list, but for now I'm going to bow out of this thread.<BR>> <BR>> Thanks,<BR>> <BR>> Mark<BR>> <BR>> -----Original Message-----<BR>> From: nsrca-discussion-bounces@lists.nsrca.org<BR>> [mailto:nsrca-discussion-bounces@lists.nsrca.org] On Behalf Of Anthony<BR>> Frackowiak<BR>> Sent: Tuesday, August 25, 2009 12:55 AM<BR>> To: General pattern discussion<BR>> Subject: Re: [NSRCA-discussion] SD-10<BR>> <BR>> I'll try to explain this as I understand it. With a 2048 system you<BR>> get 2048 TX step outputs through the entire stick travel only if the<BR>> electronic throws in the TX are set to Max. Say that's 150% Travel at<BR>> 100% Dual Rate. Those numbers vary amongst the brands and models but<BR>> this is a start. Any reduction from there will reduce the 2048 by some<BR>> percentage. Let's say Travel is set to 100% and Dual Rate remains<BR>> 100%. You have just reduced the number of steps by 33% so now you're<BR>> down to around 1350. If you reduce the Dual Rate to 80% from there<BR>> you're now flying on 1080. If this started out as a 1024 you would end<BR>> up at 540. I guarantee you'll feel the difference between 1080 and 540.<BR>> <BR>> I always try to maximize the electronic throws and set the mechanicals<BR>> to get the surface travel I desire. But some things are inevitable. To<BR>> get the model to properly break in a spin takes a lot of elevator<BR>> deflection, so I end up flying with DR set to 50% or so for normal<BR>> flying. The higher 2048 system makes a difference with this sort of an<BR>> example. And I do believe the better servos will respond to this fine<BR>> of a command.<BR>> <BR>> Hope this isn't too confusing.<BR>> <BR>> TonyF<BR>> <BR>> <BR>> <BR>> On Aug 24, 2009, at 8:14 PM, Atwood, Mark wrote:<BR>> <BR>> > The resolution is for the full throw of the servo. If you bump your<BR>> > endpoints up to 150% and have 135deg of travel, you have 512 / 1024<BR>> > or 2048 individual points in between. At a normal 100% that's<BR>> > across 90degs of throw. If you dial your endpoints down, it's<BR>> > spread across a smaller arc.<BR>> ><BR>> > We're talking about extremely fine movement even at 512 resolution.<BR>> ><BR>> > What's nice is that all the components of the Accuracy "system" are<BR>> > improving together. The pots in the new radios (all brands) are<BR>> > significantly more accurate, the digital servos of all brands are<BR>> > significantly more accurate, and our linkage systems continue to<BR>> > improve as well. My argument was simply that after 1024 (and<BR>> > probably lower actually), the resolution is probably not the "weak<BR>> > link" in the accuracy chain. We have too much slop elsewhere. Even<BR>> > a tight servo has some lash, as do the connections to the servo and<BR>> > even movement of the control surface on the hingeline.<BR>> ><BR>> > Admittedly though, On a LARGE control surface like a 40% IMAC<BR>> > Rudder, you can still see the surface "Step" if you move it slowly<BR>> > and watch carefully even with 1024. So to say that 2048 is not<BR>> > smoother would be foolish. But on our pattern planes and the throws<BR>> > we use, the other sources of error take resolution off the critical<BR>> > path to more accuracy.<BR>> ><BR>> > So to slightly change the topic, how do we get spec's on the<BR>> > resolution/accuracy of the servos? Does anyone publish that? (I'm<BR>> > pretty sure Atx doesn't). That would be as important than just<BR>> > about any other spec I would think.<BR>> ><BR>> > -----Original Message-----<BR>> > From: nsrca-discussion-bounces@lists.nsrca.org<BR>> [mailto:nsrca-discussion-bounces@lists.nsrca.org<BR>> > ] On Behalf Of Lisa n Larry<BR>> > Sent: Monday, August 24, 2009 10:31 PM<BR>> > To: 'General pattern discussion'<BR>> > Subject: Re: [NSRCA-discussion] SD-10<BR>> ><BR>> > I'm curious...<BR>> ><BR>> > How many degree of servo throw for 1024/2048 are we talking?<BR>> ><BR>> > -----Original Message-----<BR>> > From: nsrca-discussion-bounces@lists.nsrca.org<BR>> > [mailto:nsrca-discussion-bounces@lists.nsrca.org] On Behalf Of<BR>> > Ronald Van<BR>> > Putte<BR>> > Sent: Monday, August 24, 2009 8:34 PM<BR>> > To: General pattern discussion<BR>> > Subject: Re: [NSRCA-discussion] SD-10<BR>> ><BR>> > Geez! I was happy with 512.<BR>> ><BR>> > Ron VP<BR>> ><BR>> > On Aug 24, 2009, at 3:13 PM, mike mueller wrote:<BR>> ><BR>> >> So a 2048 is smoother than a 1024 by double. I wonder at what<BR>> >> point you no longet "feel the difference".?<BR>> >> For me it could be as soon as tomorrow. M2<BR>> >><BR>> >> --- On Mon, 8/24/09, Jay Marshall <lightfoot@sc.rr.com> wrote:<BR>> >><BR>> >>> From: Jay Marshall <lightfoot@sc.rr.com><BR>> >>> Subject: Re: [NSRCA-discussion] SD-10<BR>> >>> To: "'General pattern discussion'" <nsrca-<BR>> >>> discussion@lists.nsrca.org><BR>> >>> Date: Monday, August 24, 2009, 3:05 PM<BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>> Frank, you<BR>> >>> are getting your terms mixed<BR>> >>> up. The 1024 & 2048 refer to the number of<BR>> >>> "steps" from one end<BR>> >>> of the stick movement to the other. The speed, known as<BR>> >>> latency, is the time it<BR>> >>> takes from the instant you change the stick to the time the<BR>> >>> servo moves. Actually,<BR>> >>> it is the time until the servo receives the command to<BR>> >>> move. The two functions<BR>> >>> are not dependant upon each other.<BR>> >>><BR>> >>><BR>> >>><BR>> >>> As far as<BR>> >>> keeping up, that depends on<BR>> >>> servo speed. It is possible to have a switch change which<BR>> >>> instantly commands a<BR>> >>> function from low to high, for example. The time to get<BR>> >>> there, however, will<BR>> >>> depend on how fast the servo can move.<BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>> Jay Marshall<BR>> >>><BR>> >>><BR>> >>><BR>> >>> -----Original<BR>> >>> Message-----<BR>> >>><BR>> >>> From:<BR>> >>> nsrca-discussion-bounces@lists.nsrca.org<BR>> >>> [mailto:nsrca-discussion-bounces@lists.nsrca.org]<BR>> >>> On Behalf Of<BR>> >>> frank<BR>> >>><BR>> >>> Sent: Monday,<BR>> >>> August 24,<BR>> >>> 2009<BR>> >>> 3:30<BR>> >>> PM<BR>> >>><BR>> >>> To:<BR>> >>> 'General pattern<BR>> >>> discussion'<BR>> >>><BR>> >>> Subject:<BR>> >>> [NSRCA-discussion] SD-10<BR>> >>><BR>> >>><BR>> >>><BR>> >>> Hi Anthony,<BR>> >>> Jim, Mark , and Others<BR>> >>> who Responded,<BR>> >>><BR>> >>><BR>> >>><BR>> >>> Thanks for<BR>> >>> your valuable input.<BR>> >>> I've read that this radio's resolution is or is<BR>> >>> among the very<BR>> >>> fastest; so much so that even digital servos<BR>> >>> can't keep up with it.<BR>> >>> I understand that the system is 1024 , but<BR>> >>> can't help but<BR>> >>> wonder why it isn't 2048. I'm sure<BR>> >>> I'll get past my<BR>> >>> hangup, but would appreciate everyone's<BR>> >>> insight's on that<BR>> >>> one.<BR>> >>><BR>> >>><BR>> >>><BR>> >>> Thanks,<BR>> >>><BR>> >>> Frank<BR>> >>> Imbriaco<BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>><BR>> >>> -----Inline Attachment Follows-----<BR>> >>><BR>> >>> _______________________________________________<BR>> >>> NSRCA-discussion mailing list<BR>> >>> NSRCA-discussion@lists.nsrca.org<BR>> >>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<BR>> >><BR>> >><BR>> >><BR>> >> _______________________________________________<BR>> >> NSRCA-discussion mailing list<BR>> >> NSRCA-discussion@lists.nsrca.org<BR>> >> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<BR>> ><BR>> > _______________________________________________<BR>> > NSRCA-discussion mailing list<BR>> > NSRCA-discussion@lists.nsrca.org<BR>> > http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<BR>> ><BR>> ><BR>> ><BR>> > _______________________________________________<BR>> > NSRCA-discussion mailing list<BR>> > NSRCA-discussion@lists.nsrca.org<BR>> > http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<BR>> ><BR>> > No virus found in this incoming message.<BR>> > Checked by AVG - www.avg.com<BR>> > Version: 8.5.392 / Virus Database: 270.13.60/2311 - Release Date:<BR>> > 08/20/09 06:05:00<BR>> > _______________________________________________<BR>> > NSRCA-discussion mailing list<BR>> > NSRCA-discussion@lists.nsrca.org<BR>> > http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<BR>> <BR>> _______________________________________________<BR>> NSRCA-discussion mailing list<BR>> NSRCA-discussion@lists.nsrca.org<BR>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<BR>> <BR>> No virus found in this incoming message.<BR>> Checked by AVG - www.avg.com<BR>> Version: 8.5.392 / Virus Database: 270.13.60/2311 - Release Date: 08/20/09<BR>> 06:05:00<BR>> _______________________________________________<BR>> NSRCA-discussion mailing list<BR>> NSRCA-discussion@lists.nsrca.org<BR>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<BR>> <BR>> _______________________________________________<BR>> NSRCA-discussion mailing list<BR>> NSRCA-discussion@lists.nsrca.org<BR>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<BR></body>
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