Today's Message Index:
----------------------
1. 09:02 AM - Re: Brass bus bar (Robert L. Nuckolls, III)
2. 11:08 AM - Re: Brass bus bar (Bob McCallum)
3. 11:41 AM - How to arrange the fat wires (MLWynn@aol.com)
4. 12:27 PM - isolating mic and headphone jacks (Lincoln Keill)
5. 01:17 PM - Re: isolating mic and headphone jacks (James Kilford)
6. 01:38 PM - Re: isolating mic and headphone jacks (Bob McCallum)
7. 01:55 PM - Re: Brass bus bar (Henador Titzoff)
8. 05:41 PM - Re: Brass bus bar (Robert L. Nuckolls, III)
9. 06:49 PM - Re: Brass bus bar (rparigoris)
10. 08:57 PM - Re: isolating mic and headphone jacks (N81JG@aol.com)
Message 1
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At 10:02 PM 6/4/2011, you wrote:
>
>Thanks Bob,
>
>I found a strip of stainless. .028 thick X 3/4 wide. I believe the
>terminals of the BlueSea ANL holders are stainless.
Hmmmm . . .
Keep in mind that the threaded fasteners used to
hold things together are just that . . . designed
to hold things together. In this case we're hoping
to put sufficient 'mash' on OTHER materials that
are the current carrying conductors such that large
areas of 'gas tightness' are achieved. Those are typically
tin-plated copper terminals.
> I applied some terminal
>conductive paste for corrosion control on the aluminum ring terminals. The
>Stainless strip connects the two ANL holders. We'll see how this combo
>holds up. All parts are easily accessible and replaceable if necessary
>after flying. Thanks for the responses.
Folks who float boats have an environmental
stress not common to airplanes. Corrosion.
There's a strong reason to look for more
materials more robust in the salt-air.
But that's a trade off. Stainless is, I
believe, less conductive than brass. So
heating of the material may well contribute
to joint failure. Stainless is harder too,
the area of "gas-tightness" is lower for
the same-mate up forces. Aluminum gets you
some pretty good contact area but it is the
most reactive of the metals we've discussed.
Thick brass or thinner copper are the
materials of choice for jumpers between
fat-terminals. ESPECIALLY if those jumpers
carry starter currents. Stainless and
particularly aluminum are not recommended.
Stainless HARDWARE to hold things together
is fine . . . where conductors come together
with other conductors is our focus for
performance.
Bob . . .
Message 2
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Without going into detail of units etc, the relative resistivity of common
conductors is as follows. The best common conductor is silver, with copper a
close second. Stainless is waaay down the list. A smaller number represents
a better conductor from a purely conductive viewpoint. (The smaller the
number the less losses) Best to stick to copper conductors wherever feasible
with the possible exception of Eric's copper clad aluminium for very long
heavy runs. ( http://www.periheliondesign.com/fatwires.htm )
Silver 15.9
Copper 17.1
Aluminium 26.5
Brass 64.0
Mild steel 180
Stainless steel 720
Nichrome 1500 (used for heating elements)
Bob McC
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-
> server@matronics.com] On Behalf Of Robert L. Nuckolls, III
> Sent: Sunday, June 05, 2011 11:58 AM
> To: aeroelectric-list@matronics.com
> Subject: RE: AeroElectric-List: Brass bus bar
>
> <nuckolls.bob@aeroelectric.com>
>
> At 10:02 PM 6/4/2011, you wrote:
> >
> >Thanks Bob,
> >
> >I found a strip of stainless. .028 thick X 3/4 wide. I believe the
> >terminals of the BlueSea ANL holders are stainless.
>
> Hmmmm . . .
>
> Keep in mind that the threaded fasteners used to
> hold things together are just that . . . designed
> to hold things together. In this case we're hoping
> to put sufficient 'mash' on OTHER materials that
> are the current carrying conductors such that large
> areas of 'gas tightness' are achieved. Those are typically
> tin-plated copper terminals.
>
>
> > I applied some terminal
> >conductive paste for corrosion control on the aluminum ring terminals.
The
> >Stainless strip connects the two ANL holders. We'll see how this combo
> >holds up. All parts are easily accessible and replaceable if necessary
> >after flying. Thanks for the responses.
>
> Folks who float boats have an environmental
> stress not common to airplanes. Corrosion.
> There's a strong reason to look for more
> materials more robust in the salt-air.
>
> But that's a trade off. Stainless is, I
> believe, less conductive than brass. So
> heating of the material may well contribute
> to joint failure. Stainless is harder too,
> the area of "gas-tightness" is lower for
> the same-mate up forces. Aluminum gets you
> some pretty good contact area but it is the
> most reactive of the metals we've discussed.
>
> Thick brass or thinner copper are the
> materials of choice for jumpers between
> fat-terminals. ESPECIALLY if those jumpers
> carry starter currents. Stainless and
> particularly aluminum are not recommended.
> Stainless HARDWARE to hold things together
> is fine . . . where conductors come together
> with other conductors is our focus for
> performance.
>
>
> Bob . . .
>
>
> _-
> ====================================================
> ======
> _-
> ====================================================
> ======
> _-
> ====================================================
> ======
> _-
> ====================================================
> ======
>
>
Message 3
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| Subject: | How to arrange the fat wires |
Hi All,
I have been scratching my head about a wiring layout issue. I am wiring
an RV 8, rear mounted battery. I have a #2 wire from the primary contactor
that needs to go to the starter contactor on the far side of the firewall.
I also need a #8 or so wire to my main bus--in this case a VP-X.
So here's my question: do I run the #2 uninterrupted to the starter
contactor and then run a wire back through the firewall to the main bus or do I
break the #2 and run the bus wire more directly. I am reluctant to break
the fat wire before the starter but bringing a relatively fat wire back
through the firewall has its downside as well.
If I am going to break the #2 wire, what is the best physical method of
doing so. I have seen fiberglass pass-throughs, but I don't think they are
adequate firewall material. There are insulated posts. My auto mechanic
friend suggested terminals held together with a bolt and well insulated.
Thoughts on this?
Regards,
Michael Wynn
RV 8 Wiring
San Ramon, CA
Message 4
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| Subject: | isolating mic and headphone jacks |
I'm installing microphone and headphone jacks in my RV-7A -- both jacks com
e with built in locking tabs. -I understand how to isolate the jack itsel
f from the aluminum structure using uninsulated shoulder washers, but how t
o isolate the locking tab from the structure? -Any ideas? -Cut off the
locking tabs?
Also, I'm planning on installing both jacks vertically on the aft part of t
he arm rest (behind seatback) -- seems to be out of the way, it's not near
any other wiring and keeps the headset wires out of the way when plugged in
to the jacks -- was going to run the leads forward up under the canopy rail
where the static line lives. -Anybody have any opinion (pro or con) on t
his location?
Thanks for the help. -Do not archive.
Lincoln Keill
Message 5
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| Subject: | Re: isolating mic and headphone jacks |
Hi Lincoln,
I found the best way to choose the location was sit in the part-built Jodel
with headset and try out a few places. It's surprising how many places
interfere with your elbow during cruise, or your knee when landing, or your
kneeboard, etc...
FWIW.
James
On 5 June 2011 20:23, Lincoln Keill <airlincoln@sbcglobal.net> wrote:
> I'm installing microphone and headphone jacks in my RV-7A -- both jacks
> come with built in locking tabs. I understand how to isolate the jack
> itself from the aluminum structure using uninsulated shoulder washers, but
> *how to isolate the locking tab from the structure? Any ideas? Cut off
> the locking tabs?*
>
> Also, I'm planning on installing both jacks vertically on the aft part of
> the arm rest (behind seatback) -- seems to be out of the way, it's not near
> any other wiring and keeps the headset wires out of the way when plugged
> into the jacks -- was going to run the leads forward up under the canopy
> rail where the static line lives. *Anybody have any opinion (pro or con)
> on this location?*
> *
> *
>
Message 6
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| Subject: | isolating mic and headphone jacks |
Lincoln;
I presume you meant to say "insulated" not "un-insulated" shoulder washers?
Secondly I'm not familiar with any microphone or headphone jacks having
"locking tabs". Can you attach a photograph or link showing this feature so
that we can understand exactly what it is you're referring to and come up
with a solution for you? If it's similar to the lock tab provided on switch
anti-rotation washers, then drilling a clearance hole near the edge of your
shoulder washer to match its location might work provided the shoulder
washer is thick enough. If not, then an additional plain fibre washer added
to the shouldered washer might do the trick.
A vertical mounting of jacks behind the seatback can be quite effective in
preventing cable tangles and interference with piloting duties. It often
makes for a much cleaner, uncluttered cockpit environment. When the aircraft
design permits, the ceiling behind the seats is another good choice for the
jacks.
The cable routing you propose should be acceptable.
Bob McC
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Lincoln
Keill
Sent: Sunday, June 05, 2011 3:24 PM
Subject: AeroElectric-List: isolating mic and headphone jacks
I'm installing microphone and headphone jacks in my RV-7A -- both jacks come
with built in locking tabs. I understand how to isolate the jack itself
from the aluminum structure using uninsulated shoulder washers, but how to
isolate the locking tab from the structure? Any ideas? Cut off the locking
tabs?
Also, I'm planning on installing both jacks vertically on the aft part of
the arm rest (behind seatback) -- seems to be out of the way, it's not near
any other wiring and keeps the headset wires out of the way when plugged
into the jacks -- was going to run the leads forward up under the canopy
rail where the static line lives. Anybody have any opinion (pro or con) on
this location?
Thanks for the help. Do not archive.
Lincoln Keill
Message 7
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| Subject: | Re: Brass bus bar |
Bob,=0A=0AI'm not sure where you got those "relative resistivity" numbers b
elow, as I've always seen metals and other substances' resistance described
as Ohms/meter. -However, I checked the resistance of silver over copper
and compared them to your numbers below (15.9/17.1), and the ratios are the
same.=0A=0AI just want to point out that gold should be in there between c
opper and aluminum. -Gold is widely used in the electronics industry to p
late connector pins and sockets, on integrated circuits to connect die to p
ins and pads, and on circuit board pads. -No doubt there are countless ot
her uses for gold in electrical circuits.=0A=0AEric's fat wires are a great
trade off between resistivity, weight and volume. -It's one of the best
simple ideas to come out of the aerospace industry. -My hat off to Eric f
or being one of our vendors!=0A=0AHenador Titzoff=0A=0A=0A=0A______________
__________________=0AFrom: Bob McCallum <robert.mccallum2@sympatico.ca>=0AT
o: aeroelectric-list@matronics.com=0ASent: Sunday, June 5, 2011 2:04 PM=0AS
ubject: RE: AeroElectric-List: Brass bus bar=0A=0A--> AeroElectric-List mes
sage posted by: Bob McCallum <robert.mccallum2@sympatico.ca>=0A=0AWithout g
oing into detail of units etc, the relative resistivity of common=0Aconduct
ors is as follows. The best common conductor is silver, with copper a=0Aclo
se second. Stainless is waaay down the list. A smaller number represents=0A
a better conductor from a purely conductive viewpoint. (The smaller the=0An
umber the less losses) Best to stick to copper conductors wherever feasible
=0Awith the possible exception of Eric's copper clad aluminium for very lon
g=0Aheavy runs. ( http://www.periheliondesign.com/fatwires.htm )=0A=0ASilve
r--- --- --- 15.9=0ACopper--- --- 17.1=0AAlum
inium--- --- 26.5=0ABrass--- --- --- 64.0=0AM
ild steel--- --- 180=0AStainless steel--- 720=0ANichrome
--- --- 1500--- --- (used for heating elements)=0A
=0ABob McC=0A=0A> -----Original Message-----=0A> From: owner-aeroelectric-l
ist-server@matronics.com=0A[mailto:owner-aeroelectric-list-=0A> server@matr
onics.com] On Behalf Of Robert L. Nuckolls, III=0A> Sent: Sunday, June 05,
2011 11:58 AM=0A> To: aeroelectric-list@matronics.com=0A> Subject: RE: Aero
Electric-List: Brass bus bar=0A> =0A> --> AeroElectric-List message posted
by: "Robert L. Nuckolls, III"=0A> <nuckolls.bob@aeroelectric.com>=0A> =0A>
At 10:02 PM 6/4/2011, you wrote:=0A> >--> AeroElectric-List message posted
by: "B Tomm" <fvalarm@rapidnet.net>=0A> >=0A> >Thanks Bob,=0A> >=0A> >I fou
nd a strip of stainless.- .028 thick X 3/4 wide.- I believe the=0A> >te
rminals of the BlueSea ANL holders are stainless.=0A> =0A>- - Hmmmm .
. .=0A> =0A>- - Keep in mind that the threaded fasteners used to=0A>
- - hold things together are just that . . . designed=0A>- - to h
old things together. In this case we're hoping=0A>- - to put sufficien
t 'mash' on OTHER materials that=0A>- - are the current carrying condu
ctors such that large=0A>- - areas of 'gas tightness' are achieved. Th
ose are typically=0A>- - tin-plated copper terminals.=0A> =0A> =0A> >
- I applied some terminal=0A> >conductive paste for corrosion control on
the aluminum ring terminals.=0AThe=0A> >Stainless strip connects the two A
NL holders.- We'll see how this combo=0A> >holds up.- All parts are eas
ily accessible and replaceable if necessary=0A> >after flying.- Thanks fo
r the responses.=0A> =0A>- - - Folks who float boats have an environm
ental=0A>- - - stress not common to airplanes. Corrosion.=0A>- -
- There's a strong reason to look for more=0A>- - - materials more
robust in the salt-air.=0A> =0A>- - - But that's a trade off. Stainle
ss is, I=0A>- - - believe, less conductive than brass. So=0A>- -
- heating of the material may well contribute=0A>- - - to joint fai
lure. Stainless is harder too,=0A>- - - the area of "gas-tightness" i
s lower for=0A>- - - the same-mate up forces. Aluminum gets you=0A>
- - - some pretty good contact area but it is the=0A>- - - most
reactive of the metals we've discussed.=0A> =0A>- - - Thick brass or
thinner copper are the=0A>- - - materials of choice for jumpers betw
een=0A>- - - fat-terminals. ESPECIALLY if those jumpers=0A>- -
- carry starter currents. Stainless and=0A>- - - particularly alumi
num are not recommended.=0A>- - - Stainless HARDWARE to hold things t
ogether=0A>- - - is fine . . . where conductors come together=0A>-
- - with other conductors is our focus for=0A>- - - performance.
======================0A> ==
====================0A> ====
==
Message 8
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| Subject: | Re: Brass bus bar |
At 04:52 PM 6/5/2011, you wrote:
>Bob,
>
>I'm not sure where you got those "relative resistivity" numbers
>below, as I've always seen metals and other substances' resistance
>described as Ohms/meter. However, I checked the resistance of
>silver over copper and compared them to your numbers below
>(15.9/17.1), and the ratios are the same.
There's a fist full of ways to describe the relative
resistance of materials. Obviously, it's a volume thing.
A bar of copper 1" square and 10' long will show a much
lower resistance than a .1" square that is also 10' long.
Any chart that speaks to relative resistivity of materials
will be incomplete without building definitions around
the samples for which the numbers are cited. For example.
Here's a chart I found on the 'net . . .
http://tinyurl.com/3w4m4kp
Emacs!
Some resistivity charts have been published using copper
as a baseline and assigning it the value 1.0 with all other
metals compared to copper. Similar charts have been made
with silver having the base-line assignment of 1.0. MOST
such charts are used to calculate the ratio of RELATIVE
resistance between two different materials.
The chart above does us the service of adding a cross-section
that's well known, like 10AWG wire. Note the similarity
of this value to the resistance for copper wire published in
the 'Connection. VERY close to 1 millohm/foot.
RESISTANCE is always a point-to-point measurement like
from one end of a resistor to the other, two different
points in a circuit, one end of a wire to another. The
value observed may be the sum effects of many resistances.
RESISTIVITY always speaks to the volumetric resistance
of a homogenous but otherwise single material . . . like
a bar of brass, copper or stainless steel.
>I just want to point out that gold should be in there between copper
>and aluminum. Gold is widely used in the electronics industry to
>plate connector pins and sockets, on integrated circuits to connect
>die to pins and pads, and on circuit board pads. No doubt there are
>countless other uses for gold in electrical circuits.
Yes! Thanks for mentioning it. The primary use for gold
is corrosion protection. It's not a terribly good
conductor but it is very resistant to corrosion. This
explains the popularity for putting the very smallest
layers of gold on a connector's mating surfaces. Typically
50 micro-inches or less.
Bob . . .
Message 9
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| Subject: | Re: Brass bus bar |
Hi Bob
A while back I put together a list of links for galvonic and conductivity info:
http://www.europaowners.org/forums/gallery2.php?g2_itemId=87240
It's in word format, you need to click on "download document".
Ron Parigoris
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=342151#342151
Message 10
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| Subject: | Re: isolating mic and headphone jacks |
The underarm, behind seat position for the jacks in the arm rest is good. I
have mine mounted there and seems well out of the way with space beside
the seat cushions to store the headsets.
John Greaves
RV7A, N781JG
Redding, CA
In a message dated 6/5/2011 12:28:27 P.M. Pacific Daylight Time,
airlincoln@sbcglobal.net writes:
I'm installing microphone and headphone jacks in my RV-7A -- both jacks
come with built in locking tabs. I understand how to isolate the jack itself
from the aluminum structure using uninsulated shoulder washers, but how to
isolate the locking tab from the structure? Any ideas? Cut off the
locking tabs?
Also, I'm planning on installing both jacks vertically on the aft part of
the arm rest (behind seatback) -- seems to be out of the way, it's not near
any other wiring and keeps the headset wires out of the way when plugged
into the jacks -- was going to run the leads forward up under the canopy
rail where the static line lives. Anybody have any opinion (pro or con) on
this location?
Thanks for the help. Do not archive.
Lincoln Keill
(http://www.matronics.com/Navigator?AeroElectric-List)
(http://www.matronics.com/contribution)
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