---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 05/11/10: 10 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:11 AM - Re: Re: IVO Prop Motor Current Limiter and Electron ic CB (n801bh@netzero.com) 2. 07:15 AM - Re: IVO Prop System Brushes (Robert L. Nuckolls, III) 3. 10:26 AM - Alternator cooling (jonlaury) 4. 11:53 AM - Shunt/Hall Sensor placement (jonlaury) 5. 11:59 AM - Re: Alternator cooling (Robert L. Nuckolls, III) 6. 12:10 PM - Re: Re: IVO Prop Motor Current Limiter and Electron ic CB (RGent1224@aol.com) 7. 12:11 PM - Re: Re: IVO Prop Motor Current Limiter and Electronic CB (Glaeser, Dennis) 8. 12:51 PM - Re: Shunt/Hall Sensor placement (jonlaury) 9. 03:27 PM - Re: Infinity grip (Eric M. Jones) 10. 10:17 PM - Re: Re: Shunt/Hall Sensor placement (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 04:11:46 AM PST US From: "n801bh@netzero.com" Subject: Re: AeroElectric-List: re: IVO Prop Motor Current Limiter and Electron ic CB To clarify things..... Bob, it is the brushes that transfer the power to the prop motor on the hub,,, not the actual pitch change motor itself. When the first motor f ailed I did discuss this with Ron @ Ivo and he was insistant not for me to open the motor and do an autopsy on it but to just send it back. Whic h I did and he promply replaced it back then. I don't know if it tricky to open up, or there is some propritary stuff in it he doesn't was peopl e to see or what. do not archive. Ben Haas N801BH www.haaspowerair.com ---------- Original Message ---------- From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: re: IVO Prop Motor Current Limiter and Elect ronic CB olls.bob@aeroelectric.com> At 09:05 PM 5/10/2010, you wrote: st.net> > >I may be mistaken, but I thought the Ivo prop had brushes that were >rubbing all the time the prop was turning -- I.e. they transfer >power from the stationary part of the engine to the rotating prop, >which has the motor mounted on it, (which then rotates with the prop). Good questions. No doubt there are two sets of brushes. One that conducts power from the stationary airframe and rotating pitch motor assembly, a second set of brushes run on the commutator within the permanent magnet motor. So I need to expand my own question to ask which of the two brush sets is demonstrating a service-life issue. Bob . . . ======================== =========== ======================== =========== ======================== =========== ======================== =========== ____________________________________________________________ Penny Stock Jumping 2000% Sign up to the #1 voted penny stock newsletter for free today! http://thirdpartyoffers.netzero.net/TGL3241/4be9218e978ff45ebefst01vuc ________________________________ Message 2 _____________________________________ Time: 07:15:29 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: IVO Prop System Brushes At 04:20 AM 5/11/2010, you wrote: To clarify things..... Bob, it is the brushes that transfer the power to the prop motor on the hub,,, not the actual pitch change motor itself. THAT is a very difficult set of components to optimize to design goals. Brushes on alternators run on the smallest possible diameters and smooth surfaces. Smoothness reduces wear, diameter controls surface speed under the brushes. Brushes in tiny motors benefit most from their tiny commutators . . . in spite of having to run over a segmented surface. Brushes that carry power to a moving prop hub DO benefit from smooth surfaces . . . but they run 100% of the time, are exposed to environmental contaminants, and have high surface speeds. A de-ice slip ring for a three bladed prop . . . Emacs! can be about 10" in diameter and has three slip rings. Brushes are a high-maintenance item on these systems too. When the first motor failed I did discuss this with Ron @ Ivo and he was insistent not for me to open the motor and do an autopsy on it but to just send it back. Which I did and he promptly replaced it back then. I don't know if it tricky to open up, or there is some proprietary stuff in it he doesn't was people to see or what. Probably nothing sinister here. The clues that lead to good failure diagnosis can be subtle . . . they can also be fragile to the extent that they are destroyed or missed by someone opening up a device under study for the first time. I don't think I've ever encountered a situation where a supplier was attempting to keep his "dirty laundry" a secret. I've encountered many instances were well meaning but unskilled investigators trashed or missed an important data point during a teardown inspection. Bob . . . ________________________________ Message 3 _____________________________________ Time: 10:26:31 AM PST US Subject: AeroElectric-List: Alternator cooling From: "jonlaury" After scouring the archives and only one post on topic, I come to you all with an Alternator cooling question. My alternators are driven off a spur gear and hence turn opposite to their intended direction. I've built fiberglass "caps" with blast tubes over the diode plate end of the alternators to try to keep them cool, but they haven't been run yet to see if the cooling is adequate. Has anyone else dealt with this? Thanks, John Read this topic online here: http://forums.matronics.com/viewtopic.php?p=297365#297365 ________________________________ Message 4 _____________________________________ Time: 11:53:10 AM PST US Subject: AeroElectric-List: Shunt/Hall Sensor placement From: "jonlaury" In Z-13, I would like to place a Hall Sensor for the AUX Alternator between the battery contactor and the Batt Bus to locate it in the cabin and within it's recommended ambient temperature operating envelope. Ditto for the Primary Alternator between the Batt Contactor and the Main Bus. Any caveats here? If only one alternator will be online at a time, is there any reason why I should not run the alternator outputs through just one Hall Sensor? John Read this topic online here: http://forums.matronics.com/viewtopic.php?p=297368#297368 ________________________________ Message 5 _____________________________________ Time: 11:59:38 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Alternator cooling At 12:23 PM 5/11/2010, you wrote: > >After scouring the archives and only one post on topic, I come to >you all with an Alternator cooling question. > >My alternators are driven off a spur gear and hence turn opposite to >their intended direction. I've built fiberglass "caps" with blast >tubes over the diode plate end of the alternators to try to keep >them cool, but they haven't been run yet to see if the cooling is adequate. > >Has anyone else dealt with this? . . . and if they had, their stories are probably of limited or no value. Cooling studies are always accomplished on an installation- by-installation, model-by-model basis. Then the cooling studies are blessed as 'golden' because type certificated aircraft are configuration managed . . . you don't change ANYTHING without due consideration for unintended consequences. The ONLY way to ascertain your particular alternator cooling requirements are to do max angle of climb, full electrical load cooling studies with thermocouples attached to the alternator's expected hot spots. After the test data is gathered and averaged (over 5 or more climb profiles) you then correct the measured temperatures for hot-day climate conditions. Failures of alternators on OBAM aircraft due to inadequate cooling are rare. Major contributors to this rarity are light loading of alternators, minimum durations for heavy loads, plenty of air-flow in vicinity of alternator, and to some degree, luck. You've obviously 'worried' about it enough to craft specifically tailored cooling components . . . but are still unsure. I suspect it's because nobody has repeated your experiment before and there's no data to share. So if you're really compelled to know, then you'll need to fit thermocouples to your alternators bearing mounts, diode heat sink, and perhaps a couple places in the stator windings. You'll also need to fit your airplane with a load bank you can adjust to set up a nameplate rated load on the alternator along with instrumentation to read alternator voltage, current, and thermocouple temperatures. Then you get somebody to fly with you to do the flight tests. Once this data is acquired, then YOU will have become the expert for whether or not your worries were justified and extra ordinary cooling measures were necessary and useful. Bob . . . >Thanks, >John > > >Read this topic online here: > >http://forums.matronics.com/viewtopic.php?p=297365#297365 > > >Checked by AVG - www.avg.com >05/11/10 01:26:00 Bob . . . //// (o o) ===========o00o=(_)=o00o======== < Go ahead, make my day . . . > < show me where I'm wrong. > ================================ ________________________________ Message 6 _____________________________________ Time: 12:10:02 PM PST US From: RGent1224@aol.com Subject: Re: AeroElectric-List: re: IVO Prop Motor Current Limiter and Electron ic CB How is the tracking of those brushes?? I remember from way back when working on the Curtis Electric prop it was a major problem for the prop specialists to get it right. I would check and recheck them as part of the preflight to make sure they were tracking true and at say a twenty five hour check them with something like Prussian Blue or whatever Ron recommends for checking the tracking the brushes. If Prussian Blue doesn't ring a bell for you, it was what was used 60 years ago when I was working on them Know you know my age Dick In a message dated 5/11/2010 6:16:58 A.M. Central Daylight Time, n801bh@netzero.com writes: To clarify things..... Bob, it is the brushes that transfer the power to the prop motor on the hub,,, not the actual pitch change motor itself. When the first motor failed I did discuss this with _Ron @ Ivo_ (mailto:Ron@Ivo) and he was insistant not for me to open the motor and do an autopsy on it but to just send it back. Which I did and he promply replaced it back then. I don't know if it tricky to open up, or there is some propritary stuff in it he doesn't was people to see or what. do not archive. Ben Haas N801BH www.haaspowerair.com ---------- Original Message ---------- From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: re: IVO Prop Motor Current Limiter and Electronic CB At 09:05 PM 5/10/2010, you wrote: > >I may be mistaken, but I thought the Ivo prop had brushes that were >rubbing all the time the prop was turning -- I.e. they transfer >power from the stationary part of the engine to the rotating prop, >which has the motor mounted on it, (which then rotates with the prop). Good questions. No doubt there are two sets of brushes. One that conducts power from the stationary airframe and rotating pitch motor assembly, a second set of brushes run on the commutator within the permanent magnet motor. So I need to expand my own question to ask which of the two brush sets is demonstrating a service-life issue. <================================================nbsp; --> http://www.matronics.com/Navigator?AeroElectric-List ____________________________________________________________ _Penny Stock Jumping 2000% Sign up to the #1 voted penny stock newsletter for free today! _ (http://thirdpartyoffers.netzero.net/TGL3242/4be9218e978ff45ebefst01vuc) _AwesomePennyStocks.com_ (http://thirdpartyoffers.netzero.net/TGL3242/4be9218e978ff45ebefst01vuc) (http://www.matronics.com/Navigator?AeroElectric-List) (http://www.matronics.com/contribution) ________________________________ Message 7 _____________________________________ Time: 12:11:32 PM PST US From: "Glaeser, Dennis" Subject: AeroElectric-List: Re: re: IVO Prop Motor Current Limiter and Electronic CB I will validate that it is the prop brushes, not the motor brushes that are the limited wear items. For those who haven't seen the IVO, the contact rings behind the prop are just aluminum disks. The brushes are a metallic material impregnated with carbon/graphite. The aluminum contact surface becomes coated with the carbon/graphite material, which improves the wear characteristics with time. The motor assembly has a planetary gear train which drives a jack screw. A collar on the jack screw engages pins on an arm attached to the torque tubes in the prop. The prop is a composite material that flexes as the torque tube is twisted, providing the pitch adjustment. IMO, the gear train is the most vulnerable part of the system, primarily because the 'pitch stops' are rubber washers that cushion the collar as it jams against the end plates! The motor doesn't see nearly the mechanical strain that the gears do (I can't speak to the electrical strain of being mechanically stopped). A 'motor' failure may well be a gear train failure, not a failure of the electric motor itself. I also experienced such a failure, due to an installation interference. I did not disassemble the unit, but I did 'loosen' things to try to peek inside. It is a very tight assembly, so I didn't see much. I did see the motor brushes, and they, and the commutator, showed no signs of distress. I wouldn't be surprised that special jigging/tooling is required for assembly, which would explain Ron's position. This is why I like the idea of the electronic limiting feature of Bob's circuit. The reed switch is a huge improvement over guessing where the prop is set, or using the provided CB as the ultimate 'stop'. It lets the user know when the limit is reached, but doesn't prevent abuse (intentional or inadvertent). The electronic CB prevents the abuse, and can only help improve the life of the gear train and electric motor. The prop brushes will still wear as usual :-) Dennis Glaeser ------------------------------------------------------------------------ From: n801bh@netzero.com To clarify things..... Bob, it is the brushes that transfer the power to the prop motor on the hub,,, not the actual pitch change motor itself. When the first motor f ailed I did discuss this with Ron @ Ivo and he was insistent not for me to open the motor and do an autopsy on it but to just send it back. Which h I did and he promptly replaced it back then. I don't know if it tricky to open up, or there is some proprietary stuff in it he doesn't was people to see or what. do not archive. Ben Haas N801BH www.haaspowerair.com ________________________________ Message 8 _____________________________________ Time: 12:51:10 PM PST US Subject: AeroElectric-List: Re: Shunt/Hall Sensor placement From: "jonlaury" After looking long enough at my proposed HS placement, I can see that one of the shortcomings is that in the intended location, the sensors would only show alt throughput to the bus. In the case of the main bus, I could see alt output to the bus if the main contactor was open. But if it's closed, I'd have no way of knowing for sure if the alt was functioning at all because battery current throughput could be masking a dead alternator. On the batt bus there would be no way to know if the Aux alt was contributing or not. RETHINK time. Sorry for the bother. J Read this topic online here: http://forums.matronics.com/viewtopic.php?p=297377#297377 ________________________________ Message 9 _____________________________________ Time: 03:27:08 PM PST US Subject: AeroElectric-List: Re: Infinity grip From: "Eric M. Jones" Just a note: I saw a stick grip used for custom cars that had four buttons in the gear shift knob (and probably a battery) that were RF connected to a remote little switch box. (This might have controlled relays). The idea was to turn on/off NOX or lights or whatever. Cars usually don't have hollow stick shifters, so this is an advantage. I can imagine this might find some use in somebody's aircraft, especially ultralights. -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones@charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=297416#297416 ________________________________ Message 10 ____________________________________ Time: 10:17:59 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Shunt/Hall Sensor placement At 02:48 PM 5/11/2010, you wrote: After looking long enough at my proposed HS placement, I can see that one of the shortcomings is that in the intended location, the sensors would only show alt throughput to the bus. In the case of the main bus, I could see alt output to the bus if the main contactor was open. But if it's closed, I'd have no way of knowing for sure if the alt was functioning at all because battery current throughput could be masking a dead alternator. Check the chapter on batteries in the 'Connection again . . . Batteries deliver energy at 12.7 volts and BELOW while alternators deliver energy at 13.8 volts and ABOVE. If an alternator is working, it will have a positive indication of output current consisting of aircraft system loads PLUS anything the battery is asking for in order to replenish a discharge. Alternators mask dead batteries . . . but batteries don't mask anything. Further if the alternator is working, then the bus voltage is high enough to keep low voltage warning lights out which are calibrated at 13.0 volts. On the batt bus there would be no way to know if the Aux alt was contributing or not. Same principals apply for both alternators. 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