---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 10/13/03: 21 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:21 AM - List of tools (Mickey Coggins) 2. 03:06 AM - Re: Re: AeroElectric-List Digest: 28 Mags - 10/08/03 (Neville Kilford) 3. 03:49 AM - Re: List of tools (Werner Schneider) 4. 07:24 AM - Re: magneto wiring (Robert L. Nuckolls, III) 5. 07:35 AM - Re: AeroElectric-List Digest: 14 Msgs - 10/10/03 (MikeM) 6. 07:43 AM - Re: Re: Alternator Noise in Headset (Robert L. Nuckolls, III) 7. 07:57 AM - Re: Re: AeroElectric-List Digest: 28 Mags - (Robert L. Nuckolls, III) 8. 08:19 AM - Re: Re: magneto wiring (richard@riley.net) 9. 08:54 AM - Re: Grounding fuel flow sender (Gary Liming) 10. 12:37 PM - Re: Re: magneto wiring (Robert L. Nuckolls, III) 11. 12:50 PM - Re: Grounding fuel flow sender (Robert L. Nuckolls, III) 12. 01:08 PM - Re: List of tools (Mark Phillips) 13. 01:43 PM - Older 'planes (Fergus Kyle) 14. 01:55 PM - Re: Re: magneto wiring (Matt Prather) 15. 04:06 PM - Crowbar OV protection (Richard May) 16. 04:56 PM - Re: Crowbar OV protection (Rino) 17. 07:20 PM - Re: Crowbar OV protection (Robert L. Nuckolls, III) 18. 09:57 PM - Strobe head fix and silicone (Rob W M Shipley) 19. 09:58 PM - Re: Crowbar OV protection (Mark Phillips) 20. 11:00 PM - Re: Grounding fuel flow sender (Jim Jewell) 21. 11:53 PM - Pins (Steve Richard) ________________________________ Message 1 _____________________________________ Time: 01:21:43 AM PST US From: Mickey Coggins Subject: AeroElectric-List: List of tools --> AeroElectric-List message posted by: Mickey Coggins Hi, I'm just starting my RV8, and due to my geographically challenged location (mountains of Switzerland) I would like to buy all the tools, testers, and meters that I might for the electrical system of my RV8. I can get almost nothing locally, except very simple household wiring supplies. I have purchased the 'Connection, as Bob calls it, and am in the process of reading it. I'll be visiting the US next week, and I'd like to pick up as much of the stuff as I possibly can during this visit. I'll be back in the states for Thanksgiving as well, so it's not critical that I get everything in this visit. Does anyone know of a list of tools, and possibly suppliers, that I could use? I would much prefer to err on the side of having a tool that I will never use than to need something and to not have it, and have to wait for it to be delivered. I guess if I don't hear any suggestions I'll just buy everything I can find in all the aviation catalogues, but that seems a bit wasteful. Thanks! Mickey -- Mickey Coggins http://www.rv8.ch/ ________________________________ Message 2 _____________________________________ Time: 03:06:26 AM PST US From: "Neville Kilford" Subject: Re: AeroElectric-List: RE: AeroElectric-List Digest: 28 Mags - 10/08/03 --> AeroElectric-List message posted by: "Neville Kilford" Villi / Bob, Thanks for the info. Makes perfect sense as you describe, except... I was planning to use the dreaded key-operated mag / starter switch hence the thought about the relay. Perhaps its time to go for toggles instead. Cheers. Nev -- Jodel D-150 in progress UK ----- Original Message ----- From: Subject: AeroElectric-List: RE: AeroElectric-List Digest: 28 Mags - 10/08/03 > --> AeroElectric-List message posted by: > > Hi Neville > > I've just made what you want for a friend with a Druine Turbulent. One mag switch is replaced by a DPDT. One half is used as the p-lead contact. The other half is used as a tacho selector. > Dont put relays into such an installation. > > > Best regards > Villi H. Seemann > Sen. Eng. BSEE > Telephony Team > Infrastructure, Network > Phone (+45) 3333 2101 > Cell ph. (+45) 2220 7690 > FAX (+45) 3333 1130 > > > ----- Original Message ----- > From: "Trampas" > Subject: RE: AeroElectric-List: Electronic tacho & mag check > > > > --> AeroElectric-List message posted by: "Trampas" > > > > I have heard of people taking a couple of capacitors and connecting them in > > series with the P-leads, then connect both leads, after the capacitors, to > > the tach. I am not sure how well this would work with your tach. > > > > I personally would look for a different system that had the capability to > > monitor both p-leads all the time and let you know if there is any > > difference. That is an engine monitor which could notify you in flight of > > any difference in the RPMs of the left and right mag. > > > > I am currently working on building such an engine monitoring system. > > > > Trampas > > > > ________________________________ Message 3 _____________________________________ Time: 03:49:07 AM PST US From: "Werner Schneider" Subject: Re: AeroElectric-List: List of tools --> AeroElectric-List message posted by: "Werner Schneider" Hello Mickey, you're going the fast lane =(;o), you will get all the electrical tools in Switzerland, just at a much higher price =(;o(( (www.distrelec.ch). You can have a look at http://www.bandcspecialty.com/parts.html I bought from them the crimp tools, a lot of wire, the toogle buttons, plugs, fastons and the OV protection module, bus bars etc. For more details contact me direct. Before you start electrical wise you should go and design your setup with a load analysis. Werner ----- Original Message ----- From: "Mickey Coggins" Subject: AeroElectric-List: List of tools > --> AeroElectric-List message posted by: Mickey Coggins > > Hi, > > I'm just starting my RV8, and due to my geographically > challenged location (mountains of Switzerland) I would > like to buy all the tools, testers, and meters that I > might for the electrical system of my RV8. I can get > almost nothing locally, except very simple household > wiring supplies. > > I have purchased the 'Connection, as Bob calls it, and > am in the process of reading it. I'll be visiting the > US next week, and I'd like to pick up as much of the > stuff as I possibly can during this visit. I'll be > back in the states for Thanksgiving as well, so it's > not critical that I get everything in this visit. > > Does anyone know of a list of tools, and possibly > suppliers, that I could use? I would much prefer to > err on the side of having a tool that I will never use > than to need something and to not have it, and have to > wait for it to be delivered. > > I guess if I don't hear any suggestions I'll just buy > everything I can find in all the aviation catalogues, > but that seems a bit wasteful. > > Thanks! > Mickey > > > -- > Mickey Coggins > http://www.rv8.ch/ > > ________________________________ Message 4 _____________________________________ Time: 07:24:40 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: magneto wiring --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 07:24 AM 10/13/2003 +0000, you wrote: >Below is the result of your inquiry. It was submitted by >Mitch Faatz (mitchfaatz@hotmail.com) on Monday, October 13, 2003 at 00:24:29 > >Monday, October 13, 2003 > >Mitch Faatz > >, >Email: mitchfaatz@hotmail.com >Comments/Questions: Bob, bought your Connection book a few years back, >quick question: Starting an airplane with right mag energized can cause >kickback, so we start with just left on. What about inflight restart? The vast majority of airplanes (pushers being the most notable exceptions) will windmill the prop in flight. Restarting generally involves restoring fuel flow and power will resume. >1) Prop spinning: do you need to re-engage the starter every? If so, can >kickback occur? I'm guessing not since prop is spinning. Exactly . . . as long as the engine is still in motion, all you need to do is get fuel flowing again . . . assuming of course that you still have usable fuel aboard . . . >2) Prop stopped: I'm guessing kick-back can occur here. > >If kickback can occur even during engine restart, how serious is it? It can and routinely does break things . . . most notably starter castings. > I'm wondering if I should make my Right mag toggle disable the starter > circuit. Why not? > Your suggestion in Append-Z to have left mag also with momentary > starter won't work in my case because I want a starter button on my > stick. I'll have a separate 'starter' toggle with switch guard: > off=down, center=stick button enabled, up=engage starter. Dropping > switch guard will move back to started disabled. That's fine, but unless you have an impulse coupled right mag, I'd disable the starter control circuit while the right mag is ON. If you were using the traditional off-l-r-both-start keyswitch, there would be a jumper installed to effect this control philosophy and it too has no way of differentiating whether the cranking operation is in flight or on the ground. I will invite you to join us on the AeroElectric List to continue this and similar discussions. It's useful to share the information with as many folks as possible. A further benefit can be realized with membership on the list. There are lots of technically capable folks on the list who can offer suggestions too. You can join at . . . http://www.matronics.com/subscribe/ Well considered and technically elegant answers to all of your questions are waiting for you there. Also, check out the downloadable materials at http://www.aeroelectric.com Thanks! Bob . . . |---------------------------------------------------| | A lie can travel half way around the world while | | the truth is till putting on its shoes . . . | | -Mark Twain- | |---------------------------------------------------| ________________________________ Message 5 _____________________________________ Time: 07:35:33 AM PST US From: MikeM Subject: AeroElectric-List: Re: AeroElectric-List Digest: 14 Msgs - 10/10/03 --> AeroElectric-List message posted by: MikeM Get a metal aircraft! Seriously, it sounds like your transmitting antenna has a poor ground plane and/or the Standing Wave Ratio of the antenna is high. High SWR causes r.f. current to flow along the sheild of the antenna coax, and then it spreads out and flows along every piece of wiring in the entire aircraft, including the headset wiring (all of it becomes part of the ground-plane the antenna should have had...) Put a decent ground-plane under the antenna, and your problems will magically disappear... Mike M. > --> AeroElectric-List message posted by: Richard May > > In my aircraft, when I transmit on my comm radio, I hear a loud squeal in > my headset. The avionics shop said it's due to the close proximity of the > antenna to my headset, and the wire that goes across from one side of the > headset to the other picks up the signal. The airplane is all wood, and > the antenna is behind the back seat, inside the fuselage. > Is there anything that can be done to get rid of this annoying noise? ________________________________ Message 6 _____________________________________ Time: 07:43:08 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Alternator Noise in Headset --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > ><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< > > You're a gentleman and a scholar and I apologize for my > impatience. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Not a problem sir. BTW, you might consider trimming your replies to throw out sections of the previous post that do not add to the continuity of the conversation. This keeps posts reasonably short and easier to read. >If the noise is present with the alternator OFF, then I don't >see how this system can be involved. Does the tone vary in pitch >with engine rpm . . . alternator generated noises do vary in pitch >with rpm and they go away when the alternator is turned off. ><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< > > I'll have to check that on the next flight. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> High pitched whines come from three common antagonists in aircraft . . . alternators, strobe power supplies and some motors. In every case, shutting the suspect system OFF kills the noise. Strobe and Alternator noise are distinctive in their variable pitch (one with rpm, the other with each firing of the strobe system). >Do you hear the noise whether or not there is a radio >transmission being received? > ><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< > > Yes, the noise was overlaid on received radio transmissions. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> This is an important clue. This means the radios are not involved which means further that the noise is not an radiated RF propagation mode. Noise gets into audio systems mostly by conduction . . . i.e. poor grounding techniques and/or conducted into the system via the +14v bus supply. >I.e., heard in the intercom >only with microphone and radio squelch gates closed? Is >the intercom battery powered or powered from the bus? > ><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< > > From what I've determined the electrical architecture in > this plane is such a kludge that there ARE no distinct busses. For > example, in the circuit breaker panel, the ground sides of the CBs are > wired together with 14AWG wire, CB to CB in series, rather than in > parallel to a bus (which could have been as simple as a piece of > copper). As you mention in the Connection, obviously not the way to do > it. I'll show it to you in Watsonville. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Okay, it sounds like your airplane may be a good candidate for substantial rehabilitation. We can discuss this more at the seminar. >If battery powered, how about trying a new battery . . .some >audio systems become squealers when the battery voltage drops >and power source impedance goes up. ><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< > Yesterday I flew a short hop battery-only (alternator > switch off) and didn't hear any tone. As I recall voltage was about 13 V. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Good. Let's turn the alternator back on and check for (1) is noise present and (2) does it vary in pitch with rpm. Do this check with (1) minimum loads . . . turn on only those radios/audio system needed to have the potential victims active and (2) maximum loads . . . turn everything ON to get highest practical load on the alternator. >We could use your airplane as a study topic at the Watsonville seminar. > ><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< > > I'll bring it if weather permits me to get into > Watsonville VFR. > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Great. >Bring all the drawings you have. > ><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< > >The only drawings I have are the ones I'm making through reverse >engineering! But it's certainly educational. I recall high school and college teachers telling me that the best way to study in class was to make brief but good memory jogging notes. At home in the evening, transcribe your notes and ELABORATE on them based on what you have retained from the class a few hours earlier. This will create a document that will open LOTS of good memory doors when you re-read them to review for the test. Your effort to accurate document what's already installed may yield good clues as to why things don't work well now as well as lay the groundwork for upgrading the system later. It's not a wasted effort. Bob . . . ________________________________ Message 7 _____________________________________ Time: 07:57:33 AM PST US From: "Robert L. Nuckolls, III" 10/08/03 Subject: Re: AeroElectric-List: RE: AeroElectric-List Digest: 28 Mags - 10/08/03 --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" 10/08/03 At 11:06 AM 10/13/2003 +0100, you wrote: >--> AeroElectric-List message posted by: "Neville Kilford" > > >Villi / Bob, > >Thanks for the info. Makes perfect sense as you describe, except... I was >planning to use the dreaded key-operated mag / starter switch hence the >thought about the relay. Perhaps its time to go for toggles instead. > >Cheers. > >Nev Hmmmm . . . yup, them thar keyswitches do limit your options . . . Bob . . . ________________________________ Message 8 _____________________________________ Time: 08:19:49 AM PST US aeroelectric-list@matronics.com From: richard@riley.net Subject: Re: AeroElectric-List: Re: magneto wiring --> AeroElectric-List message posted by: richard@riley.net At 09:23 AM 10/13/03 -0500, Robert L. Nuckolls, III wrote: > >Comments/Questions: Bob, bought your Connection book a few years back, > >quick question: Starting an airplane with right mag energized can cause > >kickback, so we start with just left on. What about inflight restart? > > The vast majority of airplanes (pushers being the > most notable exceptions) will windmill the prop in > flight. Restarting generally involves restoring fuel > flow and power will resume. Pushers windmill the prop nicely. In a canard pusher, the windmilling prop reduces glide significantly (no more so than any other plane, but canard-pushers is where my experience is.) Depending on what the prop pitch is, since your minimum speed is limited by the canard stall speed, you may not be able to get slow enough to stop the windmilling prop. ________________________________ Message 9 _____________________________________ Time: 08:54:42 AM PST US From: Gary Liming Subject: Re: AeroElectric-List: Grounding fuel flow sender --> AeroElectric-List message posted by: Gary Liming At 09:29 PM 10/12/2003 -0700, you wrote: >--> AeroElectric-List message posted by: richard@riley.net > >I'm rebuilding the induction system on a Lyc IO-540. There's a Floscan >transducer there already, from a previous engine instrument installation, >but it looks like I'm going to have to re-position it. > >I know about keeping the fuel flow straight for as long as possible going >in and out of the transducer, but at one point I was told that the >transducer shouldn't be grounded - that it should be stepped off the engine >on insulators, and that the fuel lines before and after the transducer >should be rubber. > >This doesn't make a whole lot of sense to me, and I *really* don't want >anything but stainless line for fuel on that side of the firewall. Does >anyone know if this bit of advice is true, urban legend, or something >inbetween? The instructions I have for the Floscan transducer doesn't say anything about not being grounded. Hope that helps, Gary Liming ________________________________ Message 10 ____________________________________ Time: 12:37:52 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: magneto wiring --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 08:19 AM 10/13/2003 -0700, you wrote: >--> AeroElectric-List message posted by: richard@riley.net > >At 09:23 AM 10/13/03 -0500, Robert L. Nuckolls, III wrote: > > > > >Comments/Questions: Bob, bought your Connection book a few years back, > > >quick question: Starting an airplane with right mag energized can cause > > >kickback, so we start with just left on. What about inflight restart? > > > > The vast majority of airplanes (pushers being the > > most notable exceptions) will windmill the prop in > > flight. Restarting generally involves restoring fuel > > flow and power will resume. > >Pushers windmill the prop nicely. In a canard pusher, the windmilling prop >reduces glide significantly (no more so than any other plane, but >canard-pushers is where my experience is.) Depending on what the prop >pitch is, since your minimum speed is limited by the canard stall speed, >you may not be able to get slow enough to stop the windmilling prop. Thanks for the data point on Richard. I don't recall now where I was told that the pushers were more likely not to windmill . . . I've been belabored of that information for a number of years. Bob . . . ________________________________ Message 11 ____________________________________ Time: 12:50:11 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Grounding fuel flow sender --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 10:54 AM 10/13/2003 -0500, you wrote: >--> AeroElectric-List message posted by: Gary Liming > >At 09:29 PM 10/12/2003 -0700, you wrote: > >--> AeroElectric-List message posted by: richard@riley.net > > > >I'm rebuilding the induction system on a Lyc IO-540. There's a Floscan > >transducer there already, from a previous engine instrument installation, > >but it looks like I'm going to have to re-position it. > > > >I know about keeping the fuel flow straight for as long as possible going > >in and out of the transducer, but at one point I was told that the > >transducer shouldn't be grounded - that it should be stepped off the engine > >on insulators, and that the fuel lines before and after the transducer > >should be rubber. > > > >This doesn't make a whole lot of sense to me, and I *really* don't want > >anything but stainless line for fuel on that side of the firewall. Does > >anyone know if this bit of advice is true, urban legend, or something > >inbetween? One of the very best ways to get information about a product is to contact the folks who build it. A short not to mailto:support@flowscan.com may do wonders for your confidence with the installation. Bob . . . ________________________________ Message 12 ____________________________________ Time: 01:08:16 PM PST US From: Mark Phillips Subject: Re: AeroElectric-List: List of tools --> AeroElectric-List message posted by: Mark Phillips I heartily second Werner's suggestion- I just completed wiring my RV using tools and materials almost exclusively from B&C, including the alternator, contactors, wires etc. Once you have a firm understanding of the invaluable information in the 'Connection and have your system design firmed up, it's easy to place one order to B&C and you should be able to get the whole package sent- (you DO have UPS, don't you?) ..just order a LOT more wire and fastons than you estimate you'll need!! Bob Nuckolls, the Aeroelectric list & B&C- does it get any better? Best wishes- Mark Phillips, RV-6A Columbia, TN, USA Werner Schneider wrote: > --> AeroElectric-List message posted by: "Werner Schneider" > > Hello Mickey, > > you're going the fast lane =(;o), you will get all the electrical tools in > Switzerland, just at a much > higher price =(;o(( (www.distrelec.ch). > > You can have a look at http://www.bandcspecialty.com/parts.html I bought > from them the crimp tools, a lot of wire, the toogle buttons, plugs, fastons > and the OV protection module, bus bars etc. > > For more details contact me direct. > > Before you start electrical wise you should go and design your setup with a > load analysis. > > Werner > > ----- Original Message ----- > From: "Mickey Coggins" > To: > Subject: AeroElectric-List: List of tools > > > >>--> AeroElectric-List message posted by: Mickey Coggins >> > > >>Hi, >> >>I'm just starting my RV8, and due to my geographically >>challenged location (mountains of Switzerland) I would >>like to buy all the tools, testers, and meters that I >>might for the electrical system of my RV8. I can get >>almost nothing locally, except very simple household >>wiring supplies. >> >>I have purchased the 'Connection, as Bob calls it, and >>am in the process of reading it. I'll be visiting the >>US next week, and I'd like to pick up as much of the >>stuff as I possibly can during this visit. I'll be >>back in the states for Thanksgiving as well, so it's >>not critical that I get everything in this visit. >> >>Does anyone know of a list of tools, and possibly >>suppliers, that I could use? I would much prefer to >>err on the side of having a tool that I will never use >>than to need something and to not have it, and have to >>wait for it to be delivered. >> >>I guess if I don't hear any suggestions I'll just buy >>everything I can find in all the aviation catalogues, >>but that seems a bit wasteful. >> >>Thanks! >>Mickey >> >> >>-- >>Mickey Coggins >>http://www.rv8.ch/ >> >> >> > > > > > > > > ________________________________ Message 13 ____________________________________ Time: 01:43:50 PM PST US From: "Fergus Kyle" Subject: AeroElectric-List: Older 'planes --> AeroElectric-List message posted by: "Fergus Kyle" Just for info, the NA64 Yale with partial flap will stall and flick starboard to inverted, AND 30deg nose down, in 1/30 second (timed it myself). That's the interval of one video/cine shot. So it's "blue up, brown down - brown up, blue down - dead" in one swell foop. Admittedly, older aircraft require careful study, but it seems to me that certified designs require a physical warning three knots above normal stall (at least here anyway). It might be a good idea to see if yours does. Cheers, Ferg ________________________________ Message 14 ____________________________________ Time: 01:55:45 PM PST US Subject: Re: AeroElectric-List: Re: magneto wiring From: "Matt Prather" --> AeroElectric-List message posted by: "Matt Prather" Just one more comment.... I believe the cp configuration is more likely to not windmill, as compared to tractor configs. One isssue is that the cp's often run very high pitch/low diameter props (56in dia x 70in pitch is a common Varieze prop) in order to take advantage of the relative aerodynamic cleanliness of the configuration. This means that relatively high airspeeds are required for the prop to generate enough lift to make the torque on the crank to maintain rotation. Most tractor configured airplanes of similar horsepower don't use that much prop pitch. The other issue is that if the prop does stop, lots of airspeed may be required to get it going again (maybe as much as 115kts). This is peculiar to cp's as well, because the prop is most likely to stop in a position where it is hidden from the slipstream by the wings. 3 blade props on cp's are much less likely to suffer from this because you can't more than of the 3 blades behind the wing at the same time. Richard is right, in that cp's do windmill, but maybe not as readily. Sorry for the long OT. Regards, Matt Prather VE N34RD > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > > At 08:19 AM 10/13/2003 -0700, you wrote: >>--> AeroElectric-List message posted by: richard@riley.net >> >>At 09:23 AM 10/13/03 -0500, Robert L. Nuckolls, III wrote: >> >> >> > >Comments/Questions: Bob, bought your Connection book a few years >> back, quick question: Starting an airplane with right mag energized >> can cause kickback, so we start with just left on. What about >> inflight restart? >> > >> > The vast majority of airplanes (pushers being the >> > most notable exceptions) will windmill the prop in >> > flight. Restarting generally involves restoring fuel >> > flow and power will resume. >> >>Pushers windmill the prop nicely. In a canard pusher, the windmilling >> prop reduces glide significantly (no more so than any other plane, but >> canard-pushers is where my experience is.) Depending on what the prop >> pitch is, since your minimum speed is limited by the canard stall >> speed, you may not be able to get slow enough to stop the windmilling >> prop. > > Thanks for the data point on Richard. I don't recall now > where I was told that the pushers were more likely not > to windmill . . . I've been belabored of that information > for a number of years. > > Bob . . . > > > http://www.matronics.com/trouble-report ________________________________ Message 15 ____________________________________ Time: 04:06:26 PM PST US From: Richard May Subject: AeroElectric-List: Crowbar OV protection --> AeroElectric-List message posted by: Richard May I've been looking at the wiring of the crowbar overvoltage module, but one thing concerns me. What if the circuit breaker shorts out??? Then what? Total meltdown. I know of that happening once on a Lockheed L-1011, and they don't put anything but the best in those birds. The weakness of the crowbar OV system is it is totally reliant on a perfect circuit breaker. I guess the thing to do is test it constantly. ________________________________ Message 16 ____________________________________ Time: 04:56:46 PM PST US From: Rino Subject: Re: AeroElectric-List: Crowbar OV protection --> AeroElectric-List message posted by: Rino Richard May wrote: > > --> AeroElectric-List message posted by: Richard May > > I've been looking at the wiring of the crowbar overvoltage module, but one > thing concerns me. What if the circuit breaker shorts out??? Then what? > Total meltdown. > I know of that happening once on a Lockheed L-1011, and they don't put > anything but the best in those birds. The weakness of the crowbar OV system > is it is totally reliant on a perfect circuit breaker. I guess the thing to > do is test it constantly. A fuse does not short out. Rino ________________________________ Message 17 ____________________________________ Time: 07:20:11 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Crowbar OV protection --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 06:58 PM 10/13/2003 -0400, you wrote: >--> AeroElectric-List message posted by: Richard May > >I've been looking at the wiring of the crowbar overvoltage module, but one >thing concerns me. What if the circuit breaker shorts out??? Then what? >Total meltdown. >I know of that happening once on a Lockheed L-1011, and they don't put >anything but the best in those birds. The weakness of the crowbar OV system >is it is totally reliant on a perfect circuit breaker. I guess the thing to >do is test it constantly. Any ov protection system is totally reliant on solder joints that might not have been made correctly, resistors that may open, diodes that may short, transistors that may crack, etc. etc. . . . I've heard the "shorted" or "failed to open" stories for circuit breakers . . . even a few persist around RAC from back in the Beech days. Funny thing, nobody claims to have seen it personally. There were no official condition reports written or investigations as to root cause. Do you know what kind of circuit breaker was involved in the L1011 incident? There are perhaps a half dozen or more technologies that could be involved. One that comes to mind are "remote controlled" circuit breakers which are really contactors driven by specialty sensing circuits for current and a myriad of other parameters to decide when to open or stay closed. The parts count on these critters is high and the need for extra-ordinary care in qualification and fabrication is equally high. Do you know if this particular "dark-n-stormy-night" breaker was one of the simple, bi-metal devices popular in our designs (which by the way, tend to fail open) and not one of the "super breakers" that the air-transport guys are fond of? I've designed dozens of ov relay systems and have first-hand experience with making them last under the most demanding requirements levied by the OEMs. I've also documented the way they add to the voltage drops in the field supply feeder that increase probability of regulator instability. OV relays have performed reasonably well for decades. If you don't mind their shortcomings and find them more comforting, then by all means. However, I can find no documented data to suggest the crowbar system implemented with a popular, relatively low cost breaker having a bi-metal sensor is more likely to malfunction than the relay based ov protection system. You could add a fusible link to back up a breaker if you're unconvinced as to its quality and failure modes . . . or leave the breaker out completely and use a fuse. This leaves you no options for dealing with nuisance trips but then, this is just one of MANY forms of alternator failure and you're going to be ready do deal with that comfortably no mater what the cause . . . right? Bob . . . ________________________________ Message 18 ____________________________________ Time: 09:57:59 PM PST US From: "Rob W M Shipley" Subject: AeroElectric-List: Strobe head fix and silicone --> AeroElectric-List message posted by: "Rob W M Shipley" Subject: Re: AeroElectric-List: Strobe head fix >Can silicone be used to re-seal the glass lens to the transformer/plastic >base of the head ? >If so, what grade is best ? Bob's answer was Electronic grade (does not smell of vinegar). This is also known as "neutral cure" silicone and should be available for less than five bucks a tube from any auto glass shop. This is a far safer product to use around any metal construction as it is non acidic than the normal silicones which contain acetic acid. Clean the surfaces carefully with alcohol and allow to dry before applying. Depending on how thickly you apply it it can take over twenty four hours to fully cure so make sure the parts are held together at least overnight. Good luck Rob Rob W M Shipley RV9A N919RV (res) Fuselage ________________________________ Message 19 ____________________________________ Time: 09:58:29 PM PST US From: Mark Phillips Subject: Re: AeroElectric-List: Crowbar OV protection --> AeroElectric-List message posted by: Mark Phillips Total meltdown? Right up to the point that the wire changes from one conductor into several, separated by "opens"- if you are concerned about the minuscule likelihood of this event, you need to worry about a lot of other stuff- wings falling off, cats sleeping with dogs, the rapture, proof bournelli was wrong etc. Nuckolls sez a fuze here is susceptible to nuisance trips- Test your breaker- if it works, sweat the other stuff... Place your hand on the 'Connection and repeat after me- Oooooohhhhhhhmmmmmmm.......... Vooooooooollllllllllllllttttttttt.......... Aaaaaaaaaaaaaammmmmmmmmmppppppppppppppppp.................. And puh-leeeeeze, do not archive !!!!!!!! Mark Rino wrote: > --> AeroElectric-List message posted by: Rino > > Richard May wrote: > >>--> AeroElectric-List message posted by: Richard May >> >>I've been looking at the wiring of the crowbar overvoltage module, but one >>thing concerns me. What if the circuit breaker shorts out??? Then what? >>Total meltdown. >>I know of that happening once on a Lockheed L-1011, and they don't put >>anything but the best in those birds. The weakness of the crowbar OV system >>is it is totally reliant on a perfect circuit breaker. I guess the thing to >>do is test it constantly. >> > > A fuse does not short out. > > Rino > > > > > > > > ________________________________ Message 20 ____________________________________ Time: 11:00:18 PM PST US From: "Jim Jewell" Subject: Re: AeroElectric-List: Grounding fuel flow sender --> AeroElectric-List message posted by: "Jim Jewell" At 09:29 PM 10/12/2003 -0700, you wrote: AeroElectric-List message posted by: richard@riley.net I'm rebuilding the induction system on a Lyc IO-540. There's a Floscan transducer there already, from a previous engine instrument installation, but it looks like I'm going to have to re-position it. >I know about keeping the fuel flow straight for as long as possible going >in and out of the transducer, but at one point I was told that the >transducer shouldn't be grounded - that it should be stepped off the engine >on insulators, and that the fuel lines before and after the transducer >should be rubber. >This doesn't make a whole lot of sense to me, and I *really* don't want >anything but stainless line for fuel on that side of the firewall. Does >anyone know if this bit of advice is true, urban legend, or something >inbetween? From the wording of the advice you where given I would say the intent was to advise you isolate the Floscan unit from mechanical vibration as apposed to electrical grounding. The suggestion; "that it should be stepped off the engine on insulators" would make sence if you intend to mount it 'on the engine'. the internals of the unit do not take well to being unduly vibrated. Mount the Floscan on the firewall and It should work just fine. As far as your concern about grounding the unit electrically take Bob's advice and call the product maker. I expect that they will happy to set things straight for you. Jim in Kelowna ________________________________ Message 21 ____________________________________ Time: 11:53:53 PM PST US From: "Steve Richard" Subject: AeroElectric-List: Pins --> AeroElectric-List message posted by: "Steve Richard" Can the pin shown on the B&C web site (Part # S604P) be used for AMP CPC connectors? Or are the pins shown on page 566 of the mouser catalog the same as the B&C pins? http://www.bandcspecialty.com/cgi-bin/ez-catalog/cat_display.cgi?24X358218 http://www.mouser.com/catalog/615/566.pdf Part #'s 571-2050901 571-2058412 Thanks Steve Richard steve@oasissolutions.com