<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Troy, I believe your non-flower powered model is in violation of the polar bear preservation act and you should cease all further flight operations or be held in contempt of the courts.<div><br></div><div>Jim O</div><div><br></div><div>Yes I have time on my hands. Very windy today.</div><div><br></div><div><br><div><html>On May 22, 2008, at 11:30 AM, Troy A. Newman wrote:</html><br class="Apple-interchange-newline"><blockquote type="cite"> <div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2">I guess Jerry and I said the same thing for the most part. We both learned from the Master himself about this.</font></span></div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2">I have found that the pots start to show some minor signs of wear at about 80-100flights on the ailerons. And about 175-200flights on the elevator and Rudder. This is with the YS engines I usually can't tell flying the airplane that this wear is there until about 125-150flights on the ailerons. So I will look at what is going on....Oh the NATS is next week it doesn't matter if the servos have 60 flights on them...Fresh aileron servos go in.</font></span></div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2">As for the practice and local contests it depends on where I'm at in the cycle. If I'm pushing 100 flights and a contest is coming up...then I put in new ones. If only just starting to show signs of wear a very slight change in speed no hesitation....then its OK through the contest and in the next couple weeks at 15-20 flights a week it will get swapped out. I have this down to about a 15min to 20 min change. </font></span></div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2">I'm very demanding of my model but I'm probably less demanding than Tony is or was. I know Tony is very honest in that you can see a change in a new servo at about 50-60 flights. Yes you can, but I have not been able to feel that different in my models until about 125 flights usually.</font></span></div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2">I also find that the 9411SA aileron servos I'm using tend to be fine on gears for 2-3 pot changes. Again if its the NATS it gets a fresh servo both gears and pots. I keep very detailed logs on my flights and the servos. Its almost like a diary. Oh crap today I could NOT hit a snap to save my butt. Point rolls were not crisp or I was missing points. Guess what the first place I check...aileron servos for this problem. </font></span></div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2">When I flew the Flower powered model I got about double the life out of the servos...maybe a little more. I would say about 200-250 flights the aileron servos would start to be needing new pots. The gear wear was much better on the electric due to lower Vibes. </font></span></div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2">One big thing is how your linkages are setup and if you are using the max rotation of the servo to get your control throws. If you have things dialed way down with one to one ratios on the servo arms to control arms then the wear issues will be magnified. If you have good mechanical setups and are using the most rotation of the servo as possible these wear issues are minimized. It doesn't mean they go away just become less detrimental to your flying and precision of the model.</font></span></div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2">As Jerry Stated measuring you control throws accurately is very important.</font></span></div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2">I'll take the Jerry line here too Your Mileage may vary.</font></span></div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div dir="ltr" align="left"><span class="265040818-22052008"><font face="Arial" color="#0000ff" size="2">Troy</font></span> <hr tabindex="-1"> <font face="Tahoma" size="2"><b>From:</b> nsrca-dist7-bounces@lists.nsrca.org [<a href="mailto:nsrca-dist7-bounces@lists.nsrca.org">mailto:nsrca-dist7-bounces@lists.nsrca.org</a>] <b>On Behalf Of </b>Troy A. Newman<br><b>Sent:</b> Thursday, May 22, 2008 9:41 AM<br><b>To:</b> 'CA, AZ, HI, NV, UT'<br><b>Subject:</b> Re: [NSRCA-dist7] Servo replacement / wear - how to tell<br></font><br></div> <div></div> <div dir="ltr" align="left"><font face="Arial" color="#0000ff" size="2"><span class="734053115-22052008"><strong>See answers below:</strong></span></font></div> <div dir="ltr" align="left"><font face="Arial" size="2"><span class="734053115-22052008"></span></font> </div> <div dir="ltr" align="left"><font face="Arial" size="2"><span class="734053115-22052008"> <div><span class="611385614-22052008"><font face="Berlin Sans FB">There was some of the typical RC discussion at Hemet - and one topic that came up, as it usually does, is servo wear and replacement. With today's digital servos, I have the following questions about digital servo replacement;</font></span></div> <div><span class="611385614-22052008"><font face="Berlin Sans FB"></font></span> </div> <div><span class="611385614-22052008"><font face="Berlin Sans FB">1) what are the symptoms of a digital servo that is starting to wear out?</font></span></div> <div><span class="611385614-22052008"> <font face="Berlin Sans FB">- poor centering ? </font><font face="Arial" size="2"><span class="734053115-22052008"> <font face="Berlin Sans FB"><font size="3"> <font color="#0000ff">YES</font></font></font> </span></font></span></div> <div><span class="611385614-22052008"><font face="Berlin Sans FB" color="#0000ff" size="3"><span class="734053115-22052008"></span></font></span> </div> <div><span class="611385614-22052008"><font face="Berlin Sans FB" color="#0000ff" size="3"><span class="734053115-22052008"></span></font></span> </div> <div><span class="611385614-22052008"> <font face="Berlin Sans FB">- does this equate to a louder 'buzz' at center</font><font face="Arial" size="2"><span class="734053115-22052008"> <font face="Berlin Sans FB" size="3">, <font color="#0000ff">NO Less buzz. The pot is worn and the servo think its at center so it doesn't try to drive to center.</font></font></span></font></span></div> <div><span class="611385614-22052008"><font face="Arial" color="#0000ff" size="2"><span class="734053115-22052008"></span></font></span> </div> <div><span class="611385614-22052008"> <font face="Berlin Sans FB">- is the only way to tell this to put a servo on some sort of protractor and look at the centering?</font><font face="Arial" size="2"><span class="734053115-22052008"> <font face="Berlin Sans FB" size="3"> <font color="#0000ff">NO run the Servo test feature in your TX. If your radio doesn't have one then get a JR MatchMaker device about $20. You can plug the servo into it and cycle the servo at various speeds. You will see hesitations and stopping at center with a worn pot. This is where the servo spends most of its time and vibes will wear on the pot at this "center point". A protractor device can help you see it, but if its bad enough to need replacing you can see it with your naked eye. The servo will stop at center as it passes through. A new servo will just pass right through at the same speed with zero hesitation and no speed change.</font></font></span></font></span></div> <div><span class="611385614-22052008"><font face="Arial" color="#0000ff" size="2"><span class="734053115-22052008"></span></font></span> </div> <div><span class="611385614-22052008"> <font face="Berlin Sans FB">- does thee servo draw more current?</font><font face="Arial" size="2"><span class="734053115-22052008"> <font face="Berlin Sans FB" size="3"> <font color="#0000ff">No they draw less current. The way a servo works is the servo sees its position and it sees the commanded position to go to. This information is given to the servo by a feedback pot. A small potentiometer in the servo that is attached to the output gear. If the servo is already there very little juice is required to maintain this position. As loads increase on the flight surfaces like sitting on the ground the weight of the aileron will create a load that is trying to move the servo off its commanded position. So you get the buzz. The servo is giving power to drive back tot he commanded location. Digital servos sample this pot position like 5 times more often than an analog servo. Each time the position is sampled a small little jolt of power is applied to drive the servo back to its commanded location. This is why digital servos offer better holding power and centering. They tell the servo to go to its commanded position more often, and have less deadband in the middle where it says that as close as I can get it. If the servo pot is worn then the servo thinks that a wide area in the worn spot on the pot is good it then stops trying to drive the servo to the commanded position. It gets it close and thinks its there. This problem Goes back to the poor centering.</font></font><font color="#0000ff"> <font face="Berlin Sans FB" size="3"> So it stops 0.1deg short or goes 0.05degs long. As the pot wear gets worse the dead spot gets larger and the error gets more. Yet the servo still thinks its at the commanded location. This is not servo deadband...but the worn pot can play havoc with the servo and its deadband.</font></font></span></font></span></div> <div><span class="611385614-22052008"><font color="#0000ff"></font></span> </div> <div><span class="611385614-22052008"><font face="Berlin Sans FB">2) What tests can be performed either 'in the plane' or 'outside the plane' to determine if a servo needs to be replaced?</font></span></div> <div><span class="611385614-22052008"> <font face="Berlin Sans FB">- In plane testing would be ideal, but we must compare against a 'new' servo, so maybe this is not practical.</font><font face="Arial" size="2"><span class="734053115-22052008"> </span></font></span></div> <div><span class="611385614-22052008"><font face="Arial" size="2"><span class="734053115-22052008"></span></font></span> </div> <div><span class="611385614-22052008"><font face="Arial" size="2"><span class="734053115-22052008"><font face="Berlin Sans FB" color="#0000ff" size="3">The servos can be tested inside the plane...A pointer or throw meter device can be used to see the servo slow or hesitate at center. Using the servo monitor and the servo test function in your TX the servos will cycle slowly and you can see the hesitations. The MatchMaker device is a servo tester and servo driver. It works very well for this function. </font></span></font></span></div> <div><span class="611385614-22052008"><font face="Arial" size="2"><span class="734053115-22052008"></span></font></span> </div> <div><span class="611385614-22052008"><font face="Arial" size="2"><span class="734053115-22052008"></span></font></span> </div> <div><span class="611385614-22052008"><font face="Arial" size="2"><span class="734053115-22052008"><font color="#0000ff"><font face="Berlin Sans FB" size="3">Tony Frakowiak taught me that when the servos start to fade away the model will not lock on nearly as well. I didn't believe him until I flew the model both ways. It can make a huge difference.</font> <font face="Berlin Sans FB" size="3"> Another thing is that as the pots wear the end point adjustments will wander. So your models TX setup will change over time. Aileron differential can suffer and even mixing value will suffer as the models usually have small percentages of mix. The servos are trying to operate in the "worn spot" Where I see the biggest problem is on 4/8pt roll elements they are just not crisp and clean.</font></font></span></font></span></div> <div><span class="611385614-22052008"><font face="Berlin Sans FB" color="#0000ff" size="3"><span class="734053115-22052008"></span></font></span> </div> <div><span class="611385614-22052008"><font face="Berlin Sans FB" color="#0000ff" size="3"><span class="734053115-22052008">yes even the Flower powered models will suffer from this problem. There is vibration, it may not be as bad as the Glow powered models but it is still there and the pots and servos will wear. I flew Electric for a year and still saw servo changes with time.</span></font></span></div> <div><span class="611385614-22052008"><font face="Berlin Sans FB" color="#0000ff" size="3"><span class="734053115-22052008"></span></font></span> </div> <div><span class="611385614-22052008"><font face="Berlin Sans FB" color="#0000ff" size="3"><span class="734053115-22052008">Another factor is the gear trains will wear a little. Metal gears much worse than nylon. As the gear trains wear the servos will fight to get to commanded location and the gear slop will constantly over shoot to commanded location. So the servo will get more pot wear and it can use more current in this situation. The constant overshoot will have the servo fighting itself. This can also happen with the worn pots. Turn on the model and one surface just constantly oscillates. You either have a problem with your linkages or the servo is worn. By the way its common with poor rudder cable setups to get this problem on rudder servo in just a few flights. This is usually not the servos fault but operator error and his cable setup is not good. A poor pull pull setup can literally eat a rudder servo alive.</span></font></span></div> <div><span class="611385614-22052008"><font face="Berlin Sans FB" color="#0000ff" size="3"><span class="734053115-22052008"></span></font></span> </div> <div><span class="611385614-22052008"><font face="Berlin Sans FB" color="#0000ff" size="3"><span class="734053115-22052008">This is a reason to use the JR "SA" servos these servos have nylon gears and perform better in the vibration situations.</span></font></span></div> <div><span class="611385614-22052008"><font face="Berlin Sans FB" color="#0000ff" size="3"><span class="734053115-22052008"></span></font></span> </div> <div><span class="611385614-22052008"><font face="Berlin Sans FB" color="#0000ff" size="3"><span class="734053115-22052008">Horizon Hobby can replace the gears and pots for you. Its usually a fee of under $20 depending on which servo it is. When you consider a $100 servo the fee to make it like new again is small. </span></font></span></div> <div><span class="611385614-22052008"><font face="Berlin Sans FB" color="#0000ff" size="3"><span class="734053115-22052008"></span></font></span> </div> <div><span class="611385614-22052008"><font face="Berlin Sans FB" color="#0000ff" size="3"><span class="734053115-22052008">Troy Newman</span></font></span></div> <div><span class="611385614-22052008"><font face="Berlin Sans FB" color="#0000ff" size="3"><span class="734053115-22052008">Team JR</span></font></span></div></span></font></div><br> <div class="OutlookMessageHeader" lang="en-us" dir="ltr" align="left"> <hr tabindex="-1"> <font face="Tahoma" size="2"><b>From:</b> nsrca-dist7-bounces@lists.nsrca.org [<a href="mailto:nsrca-dist7-bounces@lists.nsrca.org">mailto:nsrca-dist7-bounces@lists.nsrca.org</a>] <b>On Behalf Of </b>Scott<br><b>Sent:</b> Thursday, May 22, 2008 8:05 AM<br><b>To:</b> <a href="mailto:dist7@nsrca.org">dist7@nsrca.org</a><br><b>Subject:</b> [NSRCA-dist7] Servo replacement / wear - how to tell<br></font><br></div> <div></div> <div><span class="611385614-22052008"><font face="Berlin Sans FB"> <div><span class="611385614-22052008"><font face="Berlin Sans FB">There was some of the typical RC discussion at Hemet - and one topic that came up, as it usually does, is servo wear and replacement. With today's digital servos, I have the following questions about digital servo replacement;</font></span></div> <div><span class="611385614-22052008"><font face="Berlin Sans FB"></font></span> </div> <div><span class="611385614-22052008"><font face="Berlin Sans FB">1) what are the symptoms of a digital servo that is starting to wear out?</font></span></div> <div><span class="611385614-22052008"> <font face="Berlin Sans FB">- poor centering ? </font></span></div> <div><span class="611385614-22052008"> <font face="Berlin Sans FB">- does this equate to a louder 'buzz' at center</font></span></div> <div><span class="611385614-22052008"> <font face="Berlin Sans FB">- is the only way to tell this to put a servo on some sort of protractor and look at the centering?</font></span></div> <div><span class="611385614-22052008"> <font face="Berlin Sans FB">- does thee servo draw more current?</font></span></div> <div><span class="611385614-22052008"></span> </div> <div><span class="611385614-22052008"><font face="Berlin Sans FB">2) What tests can be performed either 'in the plane' or 'outside the plane' to determine if a servo needs to be replaced?</font></span></div> <div><span class="611385614-22052008"> <font face="Berlin Sans FB">- In plane testing would be ideal, but we must compare against a 'new' servo, so maybe this is not practical.</font></span></div> <div><span class="611385614-22052008"><font face="Berlin Sans FB"></font></span> </div> <div><span class="611385614-22052008"><font face="Berlin Sans FB">Any thoughts on the above would be considered.</font></span></div> <div><span class="611385614-22052008"><font face="Berlin Sans FB"></font></span> </div> <div><span class="611385614-22052008"><font face="Berlin Sans FB">Thanks</font></span></div> <div><span class="611385614-22052008"><font face="Berlin Sans FB"></font></span> </div> <div><span class="611385614-22052008"><font face="Berlin Sans FB">sc</font></span></div> <div><span class="611385614-22052008"><font face="Arial" color="#0000ff" size="2"></font></span> </div></font></span><span class="611385614-22052008"><font face="Berlin Sans FB"></font></span></div></div> _______________________________________________<br>NSRCA-dist7 mailing list<br><a href="mailto:NSRCA-dist7@lists.nsrca.org">NSRCA-dist7@lists.nsrca.org</a><br>http://lists.nsrca.org/mailman/listinfo/nsrca-dist7<br></blockquote></div><br></div></body></html>