---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 12/20/20: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 10:35 AM - Re: Re: Has anyone used very high temp silicone FWF? (Ernest Christley) 2. 06:23 PM - Re: Re: Has anyone used very high temp silicone FWF? (Robert L. Nuckolls, III) 3. 09:09 PM - Re: Re: Stratux RS-232 Wx+Trfc Out to various navigators... (TImothy Shankland) ________________________________ Message 1 _____________________________________ Time: 10:35:37 AM PST US From: Ernest Christley Subject: Re: AeroElectric-List: Re: Has anyone used very high temp silicone FWF? On Saturday, December 19, 2020, 7:05:03 PM EST, Robert L. Nuckolls, III wrote: =C2-=C2- A mock firewall sheet is fitted with the proposed feed =C2-=C2- thru system. A propane fired burner is positioned a =C2-=C2- few feet off the front side of the firewall. Athermocouple =C2-=C2- is positioned about 6" off the firewall right infront =C2-=C2- of the test article. =C2-=C2- The test setup is bathed in propane powered flame =C2-=C2- sufficient to push the thermocouple reading to 2000 =C2-=C2- plus or minus a hundred or so degrees . . . for =C2-=C2- ten minutes. With all due respect, why doesn't the test require that the test article al so support the weight of firewall forward components while the test is bein g conducted?=C2- For a firewall that is held together and to the airplane with either rivets that melt at around 950F (but are mechanically useless above 500F), and epoxy that will melt above 300F (at best), all that test s hows is that your wire bundle will be safe as the pieces of your airplane c rash to the ground in different spots.=C2- Maybe the hope is that the cau lk can hold the airplane together. I understand safety margins, and a desire to get the best protection availa ble.=C2- But as with everything else, there comes a point when the search for safety crosses over to being useless, then comical, or may even reach counter productive. I wonder if Mr. Thurman has run the test on a firewall connected to fuselage and engine to see how long they stay together.=C2- The front half of a fuselage that is already heading to the recycle plant w ould be all that's necessary. ________________________________ Message 2 _____________________________________ Time: 06:23:44 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Has anyone used very high temp silicone FWF? On Saturday, December 19, 2020, 7:05:03 PM EST, Robert L. Nuckolls, III wrote: A mock firewall sheet is fitted with the proposed feed thru system. A propane fired burner is positioned a few feet off the front side of the firewall. A thermocouple is positioned about 6" off the firewall right in front of the test article. The test setup is bathed in propane powered flame sufficient to push the thermocouple reading to 2000 plus or minus a hundred or so degrees . . . for ten minutes. With all due respect, why doesn't the test require that the test article also support the weight of firewall forward components while the test is being conducted? Not for individual, non-structural components. To be sure, there are very few such devices intended to maintain firewall integrity while taking wire bundles from one side to the other. The pass-thrus I illustrated are one such device, bulkhead electrical connectors are another. They may have tested things like cabin heat mixer boxes on that fixture. Chapter 13 of this document https://tinyurl.com/yd4kapvh speaks to those components. The handbook is 235 pages and covers a constellation of materials and applications. For a firewall that is held together and to the airplane with either rivets that melt at around 950F (but are mechanically useless above 500F), . . . this isn't a test of the firewall but only a component bolted to the firewall. and epoxy that will melt above 300F (at best), all that test shows is that your wire bundle will be safe as the pieces of your airplane crash to the ground in different spots. Maybe the hope is that the caulk can hold the airplane together. Composite aircraft are another study/ solution and may also be covered in the cited document. I understand safety margins, and a desire to get the best protection available. But as with everything else, there comes a point when the search for safety crosses over to being useless, then comical, or may even reach counter productive. I wonder if Mr. Thurman has run the test on a firewall connected to fuselage and engine to see how long they stay together. The front half of a fuselage that is already heading to the recycle plant would be all that's necessary. Dunno . . . I didn't work in that facility routinely. I only conducted tests germane to my tasks. Those were not 'searches for safety' rather qualification tests of specific components conducted in compliance with standards of the day. To be sure, firewall forward fires are rare and are fueled by either gasoline (for which you have shutoffs), engine oil which has escaped from compromised plumbing . . . or gross disassembly of the engine (thrown jug or a rod punching a hole in the crankcase). The later case is probably the impetus for testing at the really high energy levels for so long an interval of time. 6-8 qts of 50W represents a huge chunk of energy. I've often wondered about aluminum cowls burning thru and exposing the windscreen to direct flame. But keep in mind too that this thread was about tubes of fire stop goop and goos from the BigBox stores. And to be sure, about any of those would probably be adequate to the task. Given that they are shielded by the fire-sleeve. The point I would emphasize is that stuff squirted from a tube is 'messy' from the get go. Raytheon-Beech was pretty hard over for finding/developing assembly- line and field-mechanic friendly while meeting requirements cited in the FARS. This discussion is more about refinement of process than optimization of performance. Bob . . . Un impeachable logic: George Carlin asked, "If black boxes survive crashes, why don't they make the whole airplane out of that stuff?" ________________________________ Message 3 _____________________________________ Time: 09:09:37 PM PST US From: TImothy Shankland Subject: Re: AeroElectric-List: Re: Stratux RS-232 Wx+Trfc Out to various navigators... I found that commercially available cables with micro USB had too large a voltage drop for my system to work. I bought a micro USB plug that I could solder heavier wires. On Thursday, December 17, 2020, 10:07:01 PM MST, andymeyer wrote: > The CP2102 only provides the serial output. I used the Boost Buck converter, a separate module that I installed in the Box, to power the Raspberry Pi. I wired it directly to the Raspberry Pi, no t through the micro USB port. Mine is installed in the airplane. Wired to a breaker and to the IFD. I would anticipate that the MicroUSB may provide enough power assuming your runs are short and your supply is running at the upper end of the pi volta ge range. I prefer a more permanent connection than the micro USB. If you'r e using a USB GPS, you'll need to make sure that you can squeeze all four U SB devices in the 4 USB ports, or work an alternate option. You can try sho rt USB extension cables as well. They make them with 90-degree connectors w hich may help. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=499711#499711 - S - WIKI - - =C2- =C2- =C2- =C2- =C2- -Matt Dralle, List Admin. ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.