Today's Message Index:
----------------------
1. 04:27 AM - Re: Contactor vs Power Relay (Brian & Debi Shannon)
2. 06:11 AM - Re: CBA-II battery tester and $low$ NiMh cells (Ken)
3. 07:54 AM - Re: 22 ga too small? (jerb)
4. 08:03 AM - Re: Devil's advocate (Paul Schattauer)
5. 08:47 AM - Telex PC 4 aircraft intercom (Zodie Rocket)
6. 09:19 AM - "Preferred architecture" for all-electric, IFR RV with 1 EI and (Larry E. James)
7. 11:50 AM - Headset weirdness (Charlie Brame)
8. 03:19 PM - Re: 22 ga too small? (Wayne Sweet)
9. 04:33 PM - Re: 22 ga too small? (Bob C.)
10. 07:48 PM - Re: 22 ga too small? (Charlie England)
Message 1
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| Subject: | Re: Contactor vs Power Relay |
--> AeroElectric-List message posted by: "Brian & Debi Shannon" <wings@theshannons.net>
I don't have the specifics about the relays in question (although I'm
curious about the answer), but found a neat website dealing with photos of
the Bosch relays and others...seems very helpful, so I thought I'd post a
link.
- Brian
HYPERLINK "http://www.bcae1.com/relays.htm"http://www.bcae1.com/relays.htm
--
Message 2
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| Subject: | Re: CBA-II battery tester and $low$ NiMh cells |
--> AeroElectric-List message posted by: Ken <klehman@albedo.net>
Hi Jim
Yes LM317's work fine in parallel but the voltage range of interest is
so small that I think a resistor is just fine. Once the battery voltage
drops about 2 volts it is for all practical purposes fully discharged
and items will begin dropping offline. I think the number is 95%
discharged at 10.5 volts but it is in the archives a number of times.
The current through a resistor won't change that much over this voltage
range.
Ken
J. Mcculley wrote:
>--> AeroElectric-List message posted by: "J. Mcculley" <mcculleyja@starpower.net>
>
>Maybe I missed it but I don't believe anyone responded to my 4/26/05
>comment and question as repeated below. My assumption is that for
>confirming that the installed battery has adequate capacity to support
>some known endurance-buss load, a battery capacity-test should duplicate
>the constant current load that the buss must support for a
>pre-determined time. OR is it that most buss loads operate on
>proportionally less current as buss voltage drops, similar to the way a
>typical resistive load responds, and therefore a resistive test-load is
>adequate, rather than a constant-current load?
>
>
Message 3
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| Subject: | Re: 22 ga too small? |
--> AeroElectric-List message posted by: jerb <ulflyer@verizon.net>
TI/Raytheon built lots of military stuff, they don't solder terminals -
reason the wire will break at the solder point after a period of time. I
figure their a lot smarter about this than most of us. You know you don't
use solid center connector antenna wire in aircraft for the same reason.
jerb
At 08:49 AM 5/27/05 -0500, you wrote:
>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
><nuckollsr@cox.net>
>
>
> >
> >
> >I haven't had luck finding the specific thread in the archive that I was
> >thinking of - referenced a 2 stroke engine installation with wires leading
> >to controls/instrumentation. Had vibration induced failures. I did find
> >a different thread that discussed a similar scenario:
> >
> >http://www.matronics.com/searching/getmsg_script.cgi?INDEX=15989953?KEYS=
> crimping_vs._soldering?LISTNAME=AeroElectric?HITNUMBER=5?SERIAL=15200432715?SHOWBUTTONS=YES
> >
> >Message number: #10218
> >
> >I guess this goes back to 'good practice' - provide strain relief,
> >damping, and support to all structures so that vibrational mode
> >frequencies are high above any normal excitation frequency. Then strain
> >relief becomes a much less interesting issue.
> >
> >Thanks for the discussion.
>
> Hmmmm . . . there's that term "good practice" again. Let's consider
> the posting cited:
>
>We have had a series of planes having problems with wires breaking because
>the solder flowing back into the wire 3/8 to 1/2" and making a solid to
>flexible junction a little ways back from the terminal. The wire will break
>at this
>junction after a while. If it is the wrong wire things get very Quite.
>Charles Dunn Flint Hills Technical School
>
> 3/8 to 1/2" . . . sheesh! perhaps he should try to get the whole
> roll of solder flowed into those joints. Many technicians fall
> prey to a lack of observation for the deduction of cause and
> effect. When you're soldering a terminal to a wire, the FIRST
> signs of solder appearing at the wire end of the joint is the
> sign to STOP . . . any more solder will not add useful features
> to the joint.
>
>I heard someone say don't solder wires as the vibrations will crack at some
>point?
>
> Yup, one of those decades old mantras that have been circulated
> and observed with reverence . . .
>
>I installed a battery cable last night and after crimping it I soldered it.
>Now if the solder cracks, it's still been crimped - so wouldn't that be the
>best of both worlds?
>
> No, unless he also observes the need for wire support outside
> EITHER a soldered or crimped joint. When you take a stranded wire
> and crimp it into a terminal, the stranding in the wire becomes
> just as solid as if it were soldered. See:
>
>http://aeroelectric.com/articles/CrimpTools/crimptools.html
>
>and in particular . .
>
>http://aeroelectric.com/articles/CrimpTools/GL.jpg
>
> . . . here we see how the metal of the terminal and metal
> of the wire strands have become a single entity. This is
> NECESSARY for achievement of a gas-tight joint that will
> withstand the worst the environment can throw at it.
>
> If you review . . .
>
>http://aeroelectric.com/articles/terminal.pdf
>
> . . . you will see where I've described the importance
> of SUPPORT beyond the gas-tight joint . . . this applies
> whether the joint is soldered or crimped.
>
> There are practical exceptions. See:
>
>http://www.aeroelectric.com/Pictures/bndstrpl.jpg
>
> Here we see a finely stranded grounding jumper that
> has been soldered into terminals. The strands are
> so small and the flow of solder beyond the back of
> the joint is so limited as to pose no great risk to
> wire breakage when extra support is not provided.
>
> Some battery jumpers offered by B&C are assembled
> like this:
>
>http://www.aeroelectric.com/Pictures/sbl.jpg
>
> Here too the joints are soldered and the terminals
> fitted with rigid heat-shrink covers. This makes
> for a nicer looking assembly but the covers add
> little if any improvement in resistance to breaking
> for the very fine strands in the welding cable.
>
> I've considered this conversation some more last night
> and recalled that someone was concerned about "stress
> risers" in the wire. This is EXACTLY the point that
> makes the wire last . . . LACK of stress risers. The
> stranding is small so as to reduce stresses due to
> flexing (consider flexibility of 1/4" glass rod compared
> to Fiberglas strands in insulation). Review
> text and supporting figure 8-1 in the 'Connection.
>
> The Tefzel is a tough plastic . . . the term "plastic"
> implies flexibility while minimizing stress. The
> evolution of wire insulation materials from cotton
> covered rubber up through the present family of
> plastics has stepped to ever higher degrees of
> robustness and resistance to mechanical and
> chemical stresses.
>
> I was initially challenged by your request for the description
> of a repeatable experiment and after some consideration
> I came to realize that the supporting experiments in the
> case of wire have been carried out in the plastics laboratories
> for decades. Flexibility of the wire has not been an issue
> for 100+ years. Make the strands sufficiently fine and
> lost of strands due to flexing/vibration goes to zero.
> This leaves only the insulation which has taken quantum
> jumps about every 20 years to a level that makes the
> selection a VERY comfortable choice between materials
> that will in all likelihood outlast the airplane's
> service life by factors of 2-10 . . .
>
> This explains the relatively simple qualification
> requirements in Mil-W-22759. One wastes a lot of
> $time$ repeating tests that have no fallout. If there
> is no risk of a particular failure important to the
> design and application of a product, then there is
> no value in testing for that failure.
>
>
> Bob . . .
>
>
Message 4
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| Subject: | Devil's advocate |
--> AeroElectric-List message posted by: "Paul Schattauer" <chasm711@msn.com>
Dan
I flew 260 hrs in the last 12 months. 32 IFR flight plan hrs, 12 actual 1
night actual. I have never flown a trip that was IMC takeoff to touch down
and consider any night cross country IFR. If I don't file at night i am
prepared and charted to do so. I do not have a standby alternator. I have
an "E" buss and a vacuum pump with a standby vacuum system and a hand held
radio. The reasons for the vacuum system are, it only runs the horizon, is
is immune to shorts caused by water (spills or rain) and mechanical shorts.
Separating all the wires from both electrical systems looked like too much
work and its lighter. The battery backed up electrical horizon was not
available when I froze the design and would go with that if I were going to
do it over and may convert to it later anyway. There are also some new
design vacuum pumps that are supposedly bullet proof, might look at those
closely when the current vacuum pump times out. Keep up the good work, you
are a great asset to the community.
Paul Schattauer
RV8 N808PS
>From: "Dan Checkoway" <dan@rvproject.com>
>Reply-To: aeroelectric-list@matronics.com
>To: <aeroelectric-list@matronics.com>
>Subject: AeroElectric-List: Devil's advocate
>Date: Fri, 3 Jun 2005 13:11:41 -0700
>
>--> AeroElectric-List message posted by: "Dan Checkoway"
><dan@rvproject.com>
>
>Homebuilt fliers out there who are instrument rated and keep current and
>really do fly IFR in your plane...here is a poll of sorts:
>
>- What % of your flying is IFR?
>- What % of your flying is in solid IMC without a VFR "out"?
>
>I consider myself more active than the average private pilot who flies for
>fun. In the past 12 months, I flew 405 hours, 13.5 of which were actual
>instrument...3% of my flying. Approximately 3 of those hours were in solid
>IMC with no VFR "out." That's less than 1% of my flying. Zero hours IFR
>at
>night in the past year.
>
>Has anybody out there ever actually used a standby alternator in IMC?
>
>How about in VMC...has anybody had a primary alternator fail, and then flew
>multiple legs home (more than just a local hop, i.e. a real cross country
>trip) using the standby alternator?
>
>Just curious.
>
>do not archive
>)_( Dan
>RV-7 N714D
>http://www.rvproject.com
>
>
Message 5
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| Subject: | Telex PC 4 aircraft intercom |
--> AeroElectric-List message posted by: "Zodie Rocket" <zodierocket@hsfx.ca>
Does anyone have an installation manual for a Telex pc-4 intercom, I
have the unit but need to have wiring info in which to install it.
Thanks
Mark Townsend Alma, Ontario
Zodiac 601XL , Osprey 2 serial # 751
President: Kitchener/Waterloo RAA Chapter
www.ch601.org / www.ch701.com / www.Osprey2.com
Message 6
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1 mag?
| Subject: | "Preferred architecture" for all-electric, IFR RV |
with 1 EI and
1 mag?
--> AeroElectric-List message posted by: "Larry E. James" <larry@ncproto.com>
Robert L. Nuckolls, III all-electric IFR RV with 1 EI and 1
mag? wrote:
>> If I were building an airplane today, Z-13 with dual
p-mags would
>> be my choice . . . the vast majority of OBAM aircraft
being
>> constructed today have a close or close copy of a
C-172 which is
>> what Van's sells and/or recommends in his kits. I've
had at least
>>
>>
Yes; of course, Van's thinking is all about VFR. Not at all
where I'm
going or where many RV builders are going these days.
Great thread here ...... along the same lines as what I
started a few weeks ago. Above applies to Rockets as well !!
>> two builders put Z-14 in their RV-8's . . . and if
they're reading
>> this and wish to join the conversation, I'm sure they
can give
>> you persuasive monologs as to their reasoning for
those choices.
>>
>>
I've gotten some, and enjoy hearing them all.
Z-14 is where I've been leaning as well. Basically, I have
been balking
at the idea of a 2nd alternator for cost reasons, but the
more I turn it
over in my head the more I like it. You can't put a price
tag on piece
of mind.
I'm at the same place ....... and would like to know how
practical it would be to build a Z-12 / 13 combo
(essentially a dual alt / single bat using the SD-8 as the
second alt) and if desired to add the second battery later
?? What I'm seeing is that all that would be done is add
the battery (smaller than the primary is cool), add a
contactor, and add a wire run with a starter cross-feed
switch ??
>> I'm not trying to belittle anyone's offer to give you
advice or
>> an opinion but at the end of the day, the electrical
system can
>> be as personalized as your upholstery or paint job.
If you bought
>>
>>
Unlike those things, however, the set of possibilities here
is much
smaller and the set of *sane and smart* possibilities
smaller still.
>> and read the book (in particular chapter 17) what are
YOUR impressions
>> a system that meets your needs? If you have doubts,
can you articulate
>> them? It's better that we offer guidance to
re-enforce or refine
>> what's attractive to you than to give you a data dump
on what everyone
>> else is doing.
>>
>>
Springing for the 2nd alternator has been my only hickup, as
I said. I
noticed (I think - I do not have the book in front of me at
the moment)
that -14 calls for two 40A alternators. Is it even possible
to mount
two belt-driven alternators on a Lyc? When I think of a 2nd
alternator,
I think of a pump-mounted gear-driven unit. I would guess
that one of
those (the 20A B&C) would also work just fine with Z-14 with
a <20A
essential bus.
For a simpler configuration; minimizing load to the
essential buss to work with the SD-8 ???
>> Suppose you start with Z-13. Do you perceive any
shortcomings?
>> Do you have any special-needs equipment? Do you have
a FADEC or
>> EFIS system that wanders off into the woods if
powered from
>> the engine cranking battery?
>>
>>
I plan a GRT EFIS and do not think it has any problems
working off the
main battery.. one more thing to investigate.
--
Larry E. James
Bellevue, WA HR2 fuselage / systems
Message 7
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| Subject: | Headset weirdness |
--> AeroElectric-List message posted by: Charlie Brame <chasb@satx.rr.com>
If the stereo/mono suggestion made in another post is not the problem, I
suggest you write or call LightSpeed about your problem. I have found
them to be a GREAT outfit to work with. They really back up their
products with great service.
I bought a set of factory reconditioned 20XL headsets from LightSpeed
for less than half what a new set cost. After nearly three years, one of
the ear pads began to deteriorate. I wrote LightSpeed for a replacement,
and they sent me two full sets of ear pads AT NO COST. You can't beat
service like that.
Charlie Brame
RV-6A N11CB
San Antonio
--------------------------------------------
> Time: 04:04:02 PM PST US
> From: Robert Dickson
> Subject: AeroElectric-List: headset weirdness
>
> --> AeroElectric-List message posted by: Robert Dickson
>
>
> I've got two headsets, both lightspeed cross country anr sets. One was
> bought last summer and the other was purchased recently. The new set
> works great in the passenger jacks (RV-6A) but in the pilot jacks the
> sidetone is very weak. If I try to turn up the volume I get a feedback
> squeal and still can't hear the mic. The older set works great in both
> sets of jacks.
> I'm guessing that this is probably some sort of problem with the mic
> jack on the pilot side, but I can't understand why one headset works in
> those jacks while the other doesn't. The new headset has some
> improvements over the old set so I really like to be able to use it on
> the pilot side.
> anyone ever have such a problem or care to offer a solution?
>
> Robert Dickson
> RV-6A
> Carrboro NC
>
Message 8
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| Subject: | Re: 22 ga too small? |
--> AeroElectric-List message posted by: "Wayne Sweet" <w_sweet@comcast.net>
It's been my experience that the wire breaks at the crimp point so I solder
everything connection possible. I suspect that most companies crimp because
it's cost not longevity.
Wayne
----- Original Message -----
From: "jerb" <ulflyer@verizon.net>
Subject: Re: AeroElectric-List: 22 ga too small?
> --> AeroElectric-List message posted by: jerb <ulflyer@verizon.net>
>
> TI/Raytheon built lots of military stuff, they don't solder terminals -
> reason the wire will break at the solder point after a period of time. I
> figure their a lot smarter about this than most of us. You know you don't
> use solid center connector antenna wire in aircraft for the same reason.
> jerb
>
>
> At 08:49 AM 5/27/05 -0500, you wrote:
>>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
>><nuckollsr@cox.net>
>>
>>
>> >
>> >
>> >I haven't had luck finding the specific thread in the archive that I was
>> >thinking of - referenced a 2 stroke engine installation with wires
>> >leading
>> >to controls/instrumentation. Had vibration induced failures. I did
>> >find
>> >a different thread that discussed a similar scenario:
>> >
>> >http://www.matronics.com/searching/getmsg_script.cgi?INDEX=15989953?KEYS>> crimping_vs._soldering?LISTNAME=AeroElectric?HITNUMBER=5?SERIAL=15200432715?SHOWBUTTONS=YES
>> >
>> >Message number: #10218
>> >
>> >I guess this goes back to 'good practice' - provide strain relief,
>> >damping, and support to all structures so that vibrational mode
>> >frequencies are high above any normal excitation frequency. Then strain
>> >relief becomes a much less interesting issue.
>> >
>> >Thanks for the discussion.
>>
>> Hmmmm . . . there's that term "good practice" again. Let's consider
>> the posting cited:
>>
>>We have had a series of planes having problems with wires breaking because
>>the solder flowing back into the wire 3/8 to 1/2" and making a solid to
>>flexible junction a little ways back from the terminal. The wire will
>>break
>>at this
>>junction after a while. If it is the wrong wire things get very Quite.
>>Charles Dunn Flint Hills Technical School
>>
>> 3/8 to 1/2" . . . sheesh! perhaps he should try to get the whole
>> roll of solder flowed into those joints. Many technicians fall
>> prey to a lack of observation for the deduction of cause and
>> effect. When you're soldering a terminal to a wire, the FIRST
>> signs of solder appearing at the wire end of the joint is the
>> sign to STOP . . . any more solder will not add useful features
>> to the joint.
>>
>>I heard someone say don't solder wires as the vibrations will crack at
>>some
>>point?
>>
>> Yup, one of those decades old mantras that have been circulated
>> and observed with reverence . . .
>>
>>I installed a battery cable last night and after crimping it I soldered
>>it.
>>Now if the solder cracks, it's still been crimped - so wouldn't that be
>>the
>>best of both worlds?
>>
>> No, unless he also observes the need for wire support outside
>> EITHER a soldered or crimped joint. When you take a stranded wire
>> and crimp it into a terminal, the stranding in the wire becomes
>> just as solid as if it were soldered. See:
>>
>>http://aeroelectric.com/articles/CrimpTools/crimptools.html
>>
>>and in particular . .
>>
>>http://aeroelectric.com/articles/CrimpTools/GL.jpg
>>
>> . . . here we see how the metal of the terminal and metal
>> of the wire strands have become a single entity. This is
>> NECESSARY for achievement of a gas-tight joint that will
>> withstand the worst the environment can throw at it.
>>
>> If you review . . .
>>
>>http://aeroelectric.com/articles/terminal.pdf
>>
>> . . . you will see where I've described the importance
>> of SUPPORT beyond the gas-tight joint . . . this applies
>> whether the joint is soldered or crimped.
>>
>> There are practical exceptions. See:
>>
>>http://www.aeroelectric.com/Pictures/bndstrpl.jpg
>>
>> Here we see a finely stranded grounding jumper that
>> has been soldered into terminals. The strands are
>> so small and the flow of solder beyond the back of
>> the joint is so limited as to pose no great risk to
>> wire breakage when extra support is not provided.
>>
>> Some battery jumpers offered by B&C are assembled
>> like this:
>>
>>http://www.aeroelectric.com/Pictures/sbl.jpg
>>
>> Here too the joints are soldered and the terminals
>> fitted with rigid heat-shrink covers. This makes
>> for a nicer looking assembly but the covers add
>> little if any improvement in resistance to breaking
>> for the very fine strands in the welding cable.
>>
>> I've considered this conversation some more last night
>> and recalled that someone was concerned about "stress
>> risers" in the wire. This is EXACTLY the point that
>> makes the wire last . . . LACK of stress risers. The
>> stranding is small so as to reduce stresses due to
>> flexing (consider flexibility of 1/4" glass rod compared
>> to Fiberglas strands in insulation). Review
>> text and supporting figure 8-1 in the 'Connection.
>>
>> The Tefzel is a tough plastic . . . the term "plastic"
>> implies flexibility while minimizing stress. The
>> evolution of wire insulation materials from cotton
>> covered rubber up through the present family of
>> plastics has stepped to ever higher degrees of
>> robustness and resistance to mechanical and
>> chemical stresses.
>>
>> I was initially challenged by your request for the description
>> of a repeatable experiment and after some consideration
>> I came to realize that the supporting experiments in the
>> case of wire have been carried out in the plastics laboratories
>> for decades. Flexibility of the wire has not been an issue
>> for 100+ years. Make the strands sufficiently fine and
>> lost of strands due to flexing/vibration goes to zero.
>> This leaves only the insulation which has taken quantum
>> jumps about every 20 years to a level that makes the
>> selection a VERY comfortable choice between materials
>> that will in all likelihood outlast the airplane's
>> service life by factors of 2-10 . . .
>>
>> This explains the relatively simple qualification
>> requirements in Mil-W-22759. One wastes a lot of
>> $time$ repeating tests that have no fallout. If there
>> is no risk of a particular failure important to the
>> design and application of a product, then there is
>> no value in testing for that failure.
>>
>>
>> Bob . . .
>>
>>
>
>
>
Message 9
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| Subject: | Re: 22 ga too small? |
--> AeroElectric-List message posted by: "Bob C. " <flyboy.bob@gmail.com>
FWIW . . . I crimp, but a dab of solder on the "far end" where the wire just
comes through the terminal.
The solder will ensure a good electrical connection . . . it serves no
mechanical purpose . . . I guess it just make me feel better . . .
Good Luck,
Bob
On 6/4/05, Wayne Sweet <w_sweet@comcast.net> wrote:
>
> --> AeroElectric-List message posted by: "Wayne Sweet" <
> w_sweet@comcast.net>
>
> It's been my experience that the wire breaks at the crimp point so I
> solder
> everything connection possible. I suspect that most companies crimp
> because
> it's cost not longevity.
> Wayne
>
> ----- Original Message -----
> From: "jerb" <ulflyer@verizon.net>
> To: <aeroelectric-list@matronics.com>
> Subject: Re: AeroElectric-List: 22 ga too small?
>
>
> > --> AeroElectric-List message posted by: jerb <ulflyer@verizon.net>
> >
> > TI/Raytheon built lots of military stuff, they don't solder terminals -
> > reason the wire will break at the solder point after a period of time. I
> > figure their a lot smarter about this than most of us. You know you
> don't
> > use solid center connector antenna wire in aircraft for the same reason.
> > jerb
> >
> >
> > At 08:49 AM 5/27/05 -0500, you wrote:
> >>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> >><nuckollsr@cox.net>
> >>
> >>
> >> >
> >> >
> >> >I haven't had luck finding the specific thread in the archive that I
> was
> >> >thinking of - referenced a 2 stroke engine installation with wires
> >> >leading
> >> >to controls/instrumentation. Had vibration induced failures. I did
> >> >find
> >> >a different thread that discussed a similar scenario:
> >> >
> >> >
> http://www.matronics.com/searching/getmsg_script.cgi?INDEX15989953?KEYS>>
> crimping_vs._soldering?LISTNAMEAeroElectric?HITNUMBER5?SERIAL15200432715?SHOWBUTTONSYES
> >> >
> >> >Message number: #10218
> >> >
> >> >I guess this goes back to 'good practice' - provide strain relief,
> >> >damping, and support to all structures so that vibrational mode
> >> >frequencies are high above any normal excitation frequency. Then
> strain
> >> >relief becomes a much less interesting issue.
> >> >
> >> >Thanks for the discussion.
> >>
> >> Hmmmm . . . there's that term "good practice" again. Let's consider
> >> the posting cited:
> >>
> >>We have had a series of planes having problems with wires breaking
> because
> >>the solder flowing back into the wire 3/8 to 1/2" and making a solid to
> >>flexible junction a little ways back from the terminal. The wire will
> >>break
> >>at this
> >>junction after a while. If it is the wrong wire things get very Quite.
> >>Charles Dunn Flint Hills Technical School
> >>
> >> 3/8 to 1/2" . . . sheesh! perhaps he should try to get the whole
> >> roll of solder flowed into those joints. Many technicians fall
> >> prey to a lack of observation for the deduction of cause and
> >> effect. When you're soldering a terminal to a wire, the FIRST
> >> signs of solder appearing at the wire end of the joint is the
> >> sign to STOP . . . any more solder will not add useful features
> >> to the joint.
> >>
> >>I heard someone say don't solder wires as the vibrations will crack at
> >>some
> >>point?
> >>
> >> Yup, one of those decades old mantras that have been circulated
> >> and observed with reverence . . .
> >>
> >>I installed a battery cable last night and after crimping it I soldered
> >>it.
> >>Now if the solder cracks, it's still been crimped - so wouldn't that be
> >>the
> >>best of both worlds?
> >>
> >> No, unless he also observes the need for wire support outside
> >> EITHER a soldered or crimped joint. When you take a stranded wire
> >> and crimp it into a terminal, the stranding in the wire becomes
> >> just as solid as if it were soldered. See:
> >>
> >>http://aeroelectric.com/articles/CrimpTools/crimptools.html
> >>
> >>and in particular . .
> >>
> >>http://aeroelectric.com/articles/CrimpTools/GL.jpg
> >>
> >> . . . here we see how the metal of the terminal and metal
> >> of the wire strands have become a single entity. This is
> >> NECESSARY for achievement of a gas-tight joint that will
> >> withstand the worst the environment can throw at it.
> >>
> >> If you review . . .
> >>
> >>http://aeroelectric.com/articles/terminal.pdf
> >>
> >> . . . you will see where I've described the importance
> >> of SUPPORT beyond the gas-tight joint . . . this applies
> >> whether the joint is soldered or crimped.
> >>
> >> There are practical exceptions. See:
> >>
> >>http://www.aeroelectric.com/Pictures/bndstrpl.jpg
> >>
> >> Here we see a finely stranded grounding jumper that
> >> has been soldered into terminals. The strands are
> >> so small and the flow of solder beyond the back of
> >> the joint is so limited as to pose no great risk to
> >> wire breakage when extra support is not provided.
> >>
> >> Some battery jumpers offered by B&C are assembled
> >> like this:
> >>
> >>http://www.aeroelectric.com/Pictures/sbl.jpg
> >>
> >> Here too the joints are soldered and the terminals
> >> fitted with rigid heat-shrink covers. This makes
> >> for a nicer looking assembly but the covers add
> >> little if any improvement in resistance to breaking
> >> for the very fine strands in the welding cable.
> >>
> >> I've considered this conversation some more last night
> >> and recalled that someone was concerned about "stress
> >> risers" in the wire. This is EXACTLY the point that
> >> makes the wire last . . . LACK of stress risers. The
> >> stranding is small so as to reduce stresses due to
> >> flexing (consider flexibility of 1/4" glass rod compared
> >> to Fiberglas strands in insulation). Review
> >> text and supporting figure 8-1 in the 'Connection.
> >>
> >> The Tefzel is a tough plastic . . . the term "plastic"
> >> implies flexibility while minimizing stress. The
> >> evolution of wire insulation materials from cotton
> >> covered rubber up through the present family of
> >> plastics has stepped to ever higher degrees of
> >> robustness and resistance to mechanical and
> >> chemical stresses.
> >>
> >> I was initially challenged by your request for the description
> >> of a repeatable experiment and after some consideration
> >> I came to realize that the supporting experiments in the
> >> case of wire have been carried out in the plastics laboratories
> >> for decades. Flexibility of the wire has not been an issue
> >> for 100+ years. Make the strands sufficiently fine and
> >> lost of strands due to flexing/vibration goes to zero.
> >> This leaves only the insulation which has taken quantum
> >> jumps about every 20 years to a level that makes the
> >> selection a VERY comfortable choice between materials
> >> that will in all likelihood outlast the airplane's
> >> service life by factors of 2-10 . . .
> >>
> >> This explains the relatively simple qualification
> >> requirements in Mil-W-22759. One wastes a lot of
> >> $time$ repeating tests that have no fallout. If there
> >> is no risk of a particular failure important to the
> >> design and application of a product, then there is
> >> no value in testing for that failure.
> >>
> >>
> >> Bob . . .
> >>
> >>
> >
> >
> >
>
>
Message 10
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| Subject: | Re: 22 ga too small? |
--> AeroElectric-List message posted by: Charlie England <ceengland@bellsouth.net>
Bingo.
(If you hear something from a pilot in an old hangar, it just might be
an old hangar tale.)
Charlie
(old electronics tech who's seen more crimp failures than solder joint
failures, which says nothing about the inherent reliability of either one)
Wayne Sweet wrote:
>--> AeroElectric-List message posted by: "Wayne Sweet" <w_sweet@comcast.net>
>
>It's been my experience that the wire breaks at the crimp point so I solder
>everything connection possible. I suspect that most companies crimp because
>it's cost not longevity.
>Wayne
>
>----- Original Message -----
>From: "jerb" <ulflyer@verizon.net>
>To: <aeroelectric-list@matronics.com>
>Subject: Re: AeroElectric-List: 22 ga too small?
>
>
>
>
>>--> AeroElectric-List message posted by: jerb <ulflyer@verizon.net>
>>
>>TI/Raytheon built lots of military stuff, they don't solder terminals -
>>reason the wire will break at the solder point after a period of time. I
>>figure their a lot smarter about this than most of us. You know you don't
>>use solid center connector antenna wire in aircraft for the same reason.
>>jerb
>>
>>
>>At 08:49 AM 5/27/05 -0500, you wrote:
>>
>>
>>>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
>>><nuckollsr@cox.net>
>>>
>>>
>>>
>>>
>>>>I haven't had luck finding the specific thread in the archive that I was
>>>>thinking of - referenced a 2 stroke engine installation with wires
>>>>leading
>>>>to controls/instrumentation. Had vibration induced failures. I did
>>>>find
>>>>a different thread that discussed a similar scenario:
>>>>
>>>>http://www.matronics.com/searching/getmsg_script.cgi?INDEX=15989953?KEYS>> crimping_vs._soldering?LISTNAME=AeroElectric?HITNUMBER=5?SERIAL=15200432715?SHOWBUTTONS=YES
>>>>
>>>>Message number: #10218
>>>>
>>>>I guess this goes back to 'good practice' - provide strain relief,
>>>>damping, and support to all structures so that vibrational mode
>>>>frequencies are high above any normal excitation frequency. Then strain
>>>>relief becomes a much less interesting issue.
>>>>
>>>>Thanks for the discussion.
>>>>
>>>>
>>> Hmmmm . . . there's that term "good practice" again. Let's consider
>>> the posting cited:
>>>
>>>We have had a series of planes having problems with wires breaking because
>>>the solder flowing back into the wire 3/8 to 1/2" and making a solid to
>>>flexible junction a little ways back from the terminal. The wire will
>>>break
>>>at this
>>>junction after a while. If it is the wrong wire things get very Quite.
>>>Charles Dunn Flint Hills Technical School
>>>
>>> 3/8 to 1/2" . . . sheesh! perhaps he should try to get the whole
>>> roll of solder flowed into those joints. Many technicians fall
>>> prey to a lack of observation for the deduction of cause and
>>> effect. When you're soldering a terminal to a wire, the FIRST
>>> signs of solder appearing at the wire end of the joint is the
>>> sign to STOP . . . any more solder will not add useful features
>>> to the joint.
>>>
>>>I heard someone say don't solder wires as the vibrations will crack at
>>>some
>>>point?
>>>
>>> Yup, one of those decades old mantras that have been circulated
>>> and observed with reverence . . .
>>>
>>>I installed a battery cable last night and after crimping it I soldered
>>>it.
>>>Now if the solder cracks, it's still been crimped - so wouldn't that be
>>>the
>>>best of both worlds?
>>>
>>> No, unless he also observes the need for wire support outside
>>> EITHER a soldered or crimped joint. When you take a stranded wire
>>> and crimp it into a terminal, the stranding in the wire becomes
>>> just as solid as if it were soldered. See:
>>>
>>>http://aeroelectric.com/articles/CrimpTools/crimptools.html
>>>
>>>and in particular . .
>>>
>>>http://aeroelectric.com/articles/CrimpTools/GL.jpg
>>>
>>> . . . here we see how the metal of the terminal and metal
>>> of the wire strands have become a single entity. This is
>>> NECESSARY for achievement of a gas-tight joint that will
>>> withstand the worst the environment can throw at it.
>>>
>>> If you review . . .
>>>
>>>http://aeroelectric.com/articles/terminal.pdf
>>>
>>> . . . you will see where I've described the importance
>>> of SUPPORT beyond the gas-tight joint . . . this applies
>>> whether the joint is soldered or crimped.
>>>
>>> There are practical exceptions. See:
>>>
>>>http://www.aeroelectric.com/Pictures/bndstrpl.jpg
>>>
>>> Here we see a finely stranded grounding jumper that
>>> has been soldered into terminals. The strands are
>>> so small and the flow of solder beyond the back of
>>> the joint is so limited as to pose no great risk to
>>> wire breakage when extra support is not provided.
>>>
>>> Some battery jumpers offered by B&C are assembled
>>> like this:
>>>
>>>http://www.aeroelectric.com/Pictures/sbl.jpg
>>>
>>> Here too the joints are soldered and the terminals
>>> fitted with rigid heat-shrink covers. This makes
>>> for a nicer looking assembly but the covers add
>>> little if any improvement in resistance to breaking
>>> for the very fine strands in the welding cable.
>>>
>>> I've considered this conversation some more last night
>>> and recalled that someone was concerned about "stress
>>> risers" in the wire. This is EXACTLY the point that
>>> makes the wire last . . . LACK of stress risers. The
>>> stranding is small so as to reduce stresses due to
>>> flexing (consider flexibility of 1/4" glass rod compared
>>> to Fiberglas strands in insulation). Review
>>> text and supporting figure 8-1 in the 'Connection.
>>>
>>> The Tefzel is a tough plastic . . . the term "plastic"
>>> implies flexibility while minimizing stress. The
>>> evolution of wire insulation materials from cotton
>>> covered rubber up through the present family of
>>> plastics has stepped to ever higher degrees of
>>> robustness and resistance to mechanical and
>>> chemical stresses.
>>>
>>> I was initially challenged by your request for the description
>>> of a repeatable experiment and after some consideration
>>> I came to realize that the supporting experiments in the
>>> case of wire have been carried out in the plastics laboratories
>>> for decades. Flexibility of the wire has not been an issue
>>> for 100+ years. Make the strands sufficiently fine and
>>> lost of strands due to flexing/vibration goes to zero.
>>> This leaves only the insulation which has taken quantum
>>> jumps about every 20 years to a level that makes the
>>> selection a VERY comfortable choice between materials
>>> that will in all likelihood outlast the airplane's
>>> service life by factors of 2-10 . . .
>>>
>>> This explains the relatively simple qualification
>>> requirements in Mil-W-22759. One wastes a lot of
>>> $time$ repeating tests that have no fallout. If there
>>> is no risk of a particular failure important to the
>>> design and application of a product, then there is
>>> no value in testing for that failure.
>>>
>>>
>>> Bob . . .
>>>
>>>
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