Fine wire tensile strengths?
Ken S. Tucker
http://www.flickr.com/photos/35156618@N03/4754110575/
It is suspended from a rope.
I need to use very fine 120V wire (like magnetic wire),
the model uses 8# test monofilament right now and weighs
1/2 # , but a strong wind requires that 8# test.
Is there a table that gives wire gauge & tensile strength?
The current will likely be a max of 1/2 amp.
Ken
Spehro Pefhany
You can pick the material and look up the yield strength.
In Imperial units, maybe steel wire (like music wire) you could use
300,000 PSI, say.
So for something that would break at 20lbs you would need
7E-5 in^2, which is about 0.01" diameter, if I did the sums correctly.
You should calculate and test the strength and self-heating effect
before using it, of course.
Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
sp...@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
Tim Williams
If you want copper wire, I suppose electrical wire is not normally specified for it, but it's just 100 alloy copper, which I see listed as 4.8 KSI tensile yield (annealed) to 48.4 KSI (cold drawn). Electrical wire usually feels like it's in the half- to full-hard condition, so it should be around 20 KSI or better.
Be sure to mount it securely so it doesn't dig into the insulation and short out or anything.
Tim
--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms
"Ken S. Tucker" <dyna...@vianet.on.ca> wrote in message news:7ee71397-e9fe-480f...@j9g2000yqn.googlegroups.com...
Grant
Stainless or piano wire? Stronger than copper. You can do it
without insulation from insulated mounts above and in the model?
I don't remember seeing tensile strength tables for wire. You'd
need to watch for fine wire heating vs loss of tensile strength
too.
Grant.
John Larkin
<dyna...@vianet.on.ca> wrote:
8 pounds breaking strength is about about #26 regular soft copper, #28
hard-drawn copper, #30 copperclad steel. Any of them can easily handle
half an amp. That's extrapolating from the wire tables in an old copy
of "Reference Data for Radio Engineers", a very handy book.
I'd suspect that #30 piano wire, 10 mil diameter, would be fine at
half an amp too.
John
Joe
Resistance and stretch calculators for lots of materials can
be found at <http://www.allmeasures.com/Formulae/>. Eg, click the
Steel button, submit, choose resistance calculator, put in wire
area and length, etc. Or click the Young's Modulus button, put in
area, length, and load, then observe Change in Length result.
Numbers in the ARRL handbook chart of breaking load for copper
antenna wire work out to about 39000 psi for soft drawn copper
wire and 65000 psi for hard drawn so perhaps use 2 strands of
varnished #24 or #26 copper magnet wire. Those strength numbers
are higher than Tim mentioned so run deadweight tests before
testing with model. #26 is ok on ampacity. Copperclad steel
antenna wire is two or three times as strong but only 40% as
conductive.
Offhand, 60W of lighting within a model sounds like a lot. Have
you considered low-voltage wiring with high-brightness LED's?
Nunya
The problem with all these replies is that he wants to
pass 120V over a "fine wire". That will not get one much past
about twenty feet before the line drop starts to show a
huge drop. At least that is the idea I got. Otherwise why
mention 120 V at all?
Grant
Current (1/2 A) is the important factor for drop, and 120V says he
has lots of wiggle room for voltage drop, no?
Grant.
Nunya
How high (long) would this line be? That too is a factor.
And no... voltage drops with line length, not current.
The line itself is a resistor, and that means that the
other end of the line will see lower voltage.
Tim Williams
> Numbers in the ARRL handbook chart of breaking load for copper
> antenna wire work out to about 39000 psi for soft drawn copper
> wire and 65000 psi for hard drawn so perhaps use 2 strands of
> varnished #24 or #26 copper magnet wire. Those strength numbers
> are higher than Tim mentioned so run deadweight tests before
> testing with model.
65 KSI is close to the ultimate tensile strength I saw; I specified yield strength, which is a little lower of course.
The yield of dead soft copper is astonishingly low, it's like shiny pink clay. Only that, after you push it around a bit, it hardens up, and pretty soon it's so damn strong you can't bend it by hand anymore! Copper provides a particularly dramatic illustration of work hardening.
Ken S. Tucker
> "Joe" <j...@somewhere.org> wrote in messagenews:i30cnt$d59$1...@news.eternal-september.org...
> > Numbers in the ARRL handbook chart of breaking load for copper
> > antenna wire work out to about 39000 psi for soft drawn copper
> > wire and 65000 psi for hard drawn so perhaps use 2 strands of
> > varnished #24 or #26 copper magnet wire. Those strength numbers
> > are higher than Tim mentioned so run deadweight tests before
> > testing with model.
>
> 65 KSI is close to the ultimate tensile strength I saw; I specified yield strength, which is a little lower of course.
>
> The yield of dead soft copper is astonishingly low, it's like shiny pink clay. Only that, after you push it around a bit, it hardens up, and pretty soon it's so damn strong you can't bend it by hand anymore! Copper provides a particularly dramatic illustration of work hardening.
This is a Good thread Gents, good of yo'all to be interested.
To Recap,
The models will be hung ~5' , the spec is to use 120V 5W & 7W
xmas bulbs, although I can run a 3rd line for 12V sissy lamps.
(Gnd, 120V, 12V).
Using this ref
http://en.wikipedia.org/wiki/American_wire_gauge
I find 24 AWG to be ok. I used a Yield Tensile Strength of
Copper ~10,000psi, calculated area and found it to be ~4#.
(24 AWG has a dia 0.02" )
Two wires gives a strength of 8# for the Gnd & 120V, and the
ohm loss calculated for 10'.
Regards
Ken
John Larkin
Sorry, no. E + I * R, and R is proportional to length for a given wire
size.
#24 soft copper is 26 milliohms per foot. At half an amp, that will
drop 13 millivolts per foot. 100 feet would lose 1.3 volts, about 1%
of the available 120 volts.
>The line itself is a resistor, and that means that the
>other end of the line will see lower voltage.
Yes. And how much lower is proportional to the current.
John
linnix
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> On Sat, 31 Jul 2010 00:10:30 -0700 (PDT), Nunya
>
>
>
Soft copper should be fine for 10 to 20 pounds. If the OP need more,
I have some #24 copper nickel alloy wire, rated at 100KSI. It should
hold a couple hundred pounds. It might not be as conductive as pure
copper, but it's much better than steel.
John Larkin
Typo. "+" should have been "=". Missed the shift key again.
John
John Fields
The load will see lower voltage _and_ current if the wire resistance
increases.
Assuming that the load draws 1/2 ampere when there's 120V across it,
then the load will look like:
E 120V
R = --- = ------- = 240 ohms
I 0.5A
From the table at:
http://www.dossert.com/technicalinfo/barecopperwire.htm
It appears that multiplying the cross-sectional area of the wire, in
square inches, by 38.5e3, yields the maximum breaking strength of
annealed or soft-drawn copper wire.
Then, since the OP needs an 8 pound breaking strength, the minimum
cross-sectional area would need to be:
8lb
S = -------- = 0.00021 square inches
3.85e3
Consulting a copper wire table, we find that 26AWG has a
cross-sectional area of 0.0001996 square inches, and 25AWG 0.0002517.
Choosing the #25 would yield a breaking strength of about 9.7 pounds,
and it would have a diameter of 0.02 inches, or about a half a
millimeter for you metric freaks out there. ;)
To hang an airplane 20 feet from from a ceiling, say, would require 40
feet of it, and with a resistance of 39.37 ohms per thousand feet
would wind up having a total resistance of 1.3 ohms.
So, we originally had: (view in Courier)
120V
|
[24R]
|
GND
with a current in the load of half an amp and the load dissipating:
P = IE = 0.5A * 120V = 60 watts.
Now with the wire connected we'll have:
120V
|
+---E1
|
[1.3R] R1
|
+---E2
|
[240R] R2
|
GND
The current in the circuit will be:
E1 120V
I = --------- = -------- 0.497 ampere,
R1 + R2 241.3R
and the voltage across the load will be:
E2 = I R2 = 0.497A * 240R = 119.28 volts,
so you can see that when resistance is added to the circuit the
voltage across as well as the current through the load will decrease.
In this case, hardly enough to worry about, since instead of 60 watts
the load will be dissipating about 59.3 which will be undetectable to
the eye if the load is lighting.
The wire will be dissipating about 0.646 watts, and for a 40 foot
length of it, I doubt whether its increase in temperature over ambient
will even be noticeable.
John Fields
[24R] <-- oops... 240R
Nunya
> On Sat, 31 Jul 2010 00:10:30 -0700 (PDT), Nunya
>
>
>
Well any stretching will also cause the diameter to reduce, but the
other effect that such stretching has is micro-structure fracturing.
That measn the resistance will be even higher than the same
diameter wire that has not been stretched. The other thing to
worry about is that one does not twist the wire pair together as
any of the aforementioned stretching will also cause a
fracturing of the enamel on the wire as well, and a shorting
event is far more likely.
I would use three strands of a smaller wire, twisted together
and use two lengths of that, one for each run,source and return.
The three smaller strands will have a better "stretch"
characteristic than any single strand will. So, if a single #26
or #24 was chosen, then I would use like 3 #28 segments
twisted together to yield the same current capacity, but far
better tensile numbers.
But sure, for such a short run, it will be negligible.
Use Silver and get better electrical and mechanical
numbers (not plated... solid Silver).
Grant
Most people see a typo and look at the keyboard to see what it might
be :) I didn't even notice the typo, no doubt others will jump on it!
Get Larkin for a lark! :o)
Grant.
>
>John
>
Tim Williams
> And no... voltage drops with line length, not current.
Obvious troll is obvious.
Please do not feed the trolls.
John Larkin
<tmor...@charter.net> wrote:
>"Nunya" <jack_s...@cox.net> wrote in message news:c64626d4-e940-41b0...@z15g2000prn.googlegroups.com...
>> And no... voltage drops with line length, not current.
>
>Obvious troll is obvious.
>
>Please do not feed the trolls.
He's not a troll. He actually *believes* that electricity drips off
long wires somehow.
John
Tim Williams
http://xkcd.com/386/
Face it, there are higher callings in life than yelling at an inanimate computer screen.
Tim
--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms
"John Larkin" <jjla...@highNOTlandTHIStechnologyPART.com> wrote in message news:2a4a56pn5vpkoe8gj...@4ax.com...
Ken S. Tucker
"Stretching" is commonly used here,
http://en.wikipedia.org/wiki/Strain_gauge
(as I'm sure yo'all know).
The aircraft are all weather, and quite light weight, that said,
in a hefty wind or heavy snow load is what needs to be designed
for, and sometime the a/c will do a kind of snap oscillation that
causes a load spike.
> I would use three strands of a smaller wire, twisted together
> and use two lengths of that, one for each run,source and return.
> The three smaller strands will have a better "stretch"
> characteristic than any single strand will. So, if a single #26
> or #24 was chosen, then I would use like 3 #28 segments
> twisted together to yield the same current capacity, but far
> better tensile numbers.
Yes, I'll try to get AWG 24 stranded speaker wire, RS#278-1301,
(clear insulation), and test that.
We sometimes have problems sourcing parts.
> But sure, for such a short run, it will be negligible.
> Use Silver and get better electrical and mechanical
> numbers (not plated... solid Silver).
Regards
Ken
Ken S. Tucker
We're located here,
http://www.trak4.com/earco/index.html
I think "couple hundred pounds" sounds optimistic, and interesting.
Care to quote?
Regards
Ken
Ken S. Tucker
We put a a/c display into operation yesterday, as you guys
can see (compared to the top photo) the suspension wire is
too heavy.
http://www.flickr.com/photos/35156618@N03/4848740731/
The wire is ~24 gauge gray stranded speaker wire, very safe
and strong but too visible compared to 8# monofilament fish
line.
Regards all and thanks for your interest.
Ken
John Fields
<tmor...@charter.net> wrote:
>And you, for some reason, actually believe him. We'd all appreciate it if you'd simply let the troll alone.
>http://xkcd.com/386/
>Face it, there are higher callings in life than yelling at an inanimate computer screen.
>
>Tim
---
Like bottom poasting?
John Fields
<dyna...@vianet.on.ca> wrote:
>"Stretching" is commonly used here,
>http://en.wikipedia.org/wiki/Strain_gauge
>(as I'm sure yo'all know).
>
> The aircraft are all weather, and quite light weight, that said,
>in a hefty wind or heavy snow load is what needs to be designed
>for, and sometime the a/c will do a kind of snap oscillation that
>causes a load spike.
---
What I'd do would be to use a length of piano wire as the strength
member from which to hang the airplane and then just run the wiring
next to it for the electric part.
If your lighting is incandescent I doubt whether a spike would hurt
it. To be safe, though, you could connect a couple of unidirectional
TVSs in aseries opposition across the load.
Something like a couple of Littelfuse 1.5KE160A:
http://www.littelfuse.com/data/en/Data_Sheets/Littelfuse_TVS-Diode_1.5KE.pdf
should work.
You could also use a single bidirectional part but they're harder to
find.
JF
John Larkin
TWO HUNDRED DOLLARS for an electret mike in a birdhouse?
John
Ken S. Tucker
> On Sun, 1 Aug 2010 04:52:10 -0700 (PDT), "Ken S. Tucker"
>
> >"Stretching" is commonly used here,
> >http://en.wikipedia.org/wiki/Strain_gauge
> >(as I'm sure yo'all know).
>
> > The aircraft are all weather, and quite light weight, that said,
> >in a hefty wind or heavy snow load is what needs to be designed
> >for, and sometime the a/c will do a kind of snap oscillation that
> >causes a load spike.
>
> ---
> What I'd do would be to use a length of piano wire as the strength
> member from which to hang the airplane and then just run the wiring
> next to it for the electric part.
>
> If your lighting is incandescent I doubt whether a spike would hurt
> it. To be safe, though, you could connect a couple of unidirectional
> TVSs in aseries opposition across the load.
>
> Something like a couple of Littelfuse 1.5KE160A:
>
>
> should work.
>
> You could also use a single bidirectional part but they're harder to
> find.
>
> JF
Thank you Mr. Fields.
The heads up (pun) on lightning (Voltage transients) is important.
This AM we tested fine wire to breaking, it broke at 100 gms,
so I figure it's AWG 36, practically invisible, so we might try
to wrap that around 8# monofilament.
Regards
Ken
PS: My Doctor says I drink to much, then she asks, "what are you
going to do about it".
I answered, "I'll get a divorce".
Ken S. Tucker
Yes, the price ($199) is kept low by good but solid quality design,
in 15 years the product has been used, no failures have occurred.
Interestingly the main cause of failures have been from woodpeckers
(which we fixed) and dogs chewing on the cables, but we service at
cost, but that's not the unit that failed, that's abuse.
BTW, we've NEVER had a dissatisfied customer.
We have had trial units returned mainly because of street, boat and
snowmobile noise, but others order a 2nd unit for the front and back
yard.
For details kindly contact us via email.
Regards
Ken
Nunya
>
> >"Stretching" is commonly used here,
> >http://en.wikipedia.org/wiki/Strain_gauge
> >(as I'm sure yo'all know).
>
> > The aircraft are all weather, and quite light weight, that said,
> >in a hefty wind or heavy snow load is what needs to be designed
> >for, and sometime the a/c will do a kind of snap oscillation that
> >causes a load spike.
>
> ---
> What I'd do would be to use a length of piano wire as the strength
> member from which to hang the airplane and then just run the wiring
> next to it for the electric part.
>
> If your lighting is incandescent I doubt whether a spike would hurt
> it. To be safe, though, you could connect a couple of unidirectional
> TVSs in aseries opposition across the load.
>
> Something like a couple of Littelfuse 1.5KE160A:
>
>
> should work.
>
> You could also use a single bidirectional part but they're harder to
> find.
>
> JF
You got it right. Use a high tensile strength carrier strand and
spiral dress a bifilar pair over that, which is able to pass the
needed current level.
Hard mounted battery packs and LED lighting would work
too. ;-)
Nunya
You should move to wifi nets and delete the wires altogether.
John Fields
---
Great idea!
One caveat... 36AWG has a resistance of about 0.415 ohms per foot and
incandescent lamps have a very nonlinear temperature coefficient of
resistance, so you may wind up with the lamps being dimmer than you'd
like and the wire hotter than the monofilament might like.
Lightning strikes?
All bets are off! ;)
John Larkin
How about using LEDs? That are more efficient than incandescents,
wildly so if you want colors.
John
Ken S. Tucker
Oh-oh, time for homework, what I'll write needs to be tested.
Looked up max current for AWG 36, 1/4 Amp looks ok as it
is well cooled.
Over 10' the Ohms is ~4, max power to bulbs at 120V is 30W,
the wire takes 1 volt and therefore 1/4W.
In comparison, this unit, (day photo),
http://www.flickr.com/photos/35156618@N03/4850643793/
takes 7+5+5 W = 17W.
So yeah AWG 36 would be pushed.
> Lightning strikes?
> All bets are off! ;)
Lightning strikes are most dangerous if somehow they ignite
something, but a strike a few hundred feet away can produce
weird transients that attention to grounding 'should' alleviate.
Regards
Ken
PS: Incidentally, the haze in the photo is smoke from local
forest fires caused by lightning (in BC Okanagan Valley).
Ken S. Tucker
Well the xmas bulbs conform easier to the scale as seen here,
http://www.flickr.com/photos/35156618@N03/4850643793/
length being ~18",
also using a higher voltage allows smaller supply lead diameter,
there are always trade-offs in a problem like that.
A product to be sold would need to be 12V though, but we're
not near doing that yet.
Regards
Ken
Grant
Related to roasting? ;^)
Grant.
RST Engineering
Jim
On Sun, 01 Aug 2010 08:13:49 -0500, John Fields
<jfi...@austininstruments.com> wrote:
John Larkin
<jfi...@austininstruments.com> wrote:
Top boasting.
John
Jim Thompson
"Basting": top-applied flavoring deception practiced by bloviators ;-)
...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
Spice is like a sports car...
Performance only as good as the person behind the wheel.
Uwe Hercksen
Ken S. Tucker schrieb:
> I need to use very fine 120V wire (like magnetic wire),
> the model uses 8# test monofilament right now and weighs
> 1/2 # , but a strong wind requires that 8# test.
> Is there a table that gives wire gauge & tensile strength?
> The current will likely be a max of 1/2 amp.
Hello,
you might need a combination of steel wire for tensile strength and
copper wire for low resistance to the electric current. To keep the
weight low, replace copper with aluminium.
Bye
Ken S. Tucker
Hi
We did an experiment yesterday, we connected a AWG 36 wire
in series with a 100W bulb, dimmer and Current meter.
(The AWG 36 wire was carefully wrapped around a couple of
3/16" bolts and carefully snugged with nuts, a poor man's fuse).
As we turned up the dimmer we expected the wire to fuse but it
didn't, it took the full current supplying a 100W bulb, I kid you not,
that's about 0.9 amps!
We got the wire from unwrapping a reed switch and checked the
gauge twice by tensile strength.
I invite anyone else to try the experiment.
Regards
Ken
Dirk Bruere at NeoPax
> On Aug 2, 2:13 am, Uwe Hercksen<herck...@mew.uni-erlangen.de> wrote:
>> Ken S. Tucker schrieb:
>>
>>> I need to use very fine 120V wire (like magnetic wire),
>>> the model uses 8# test monofilament right now and weighs
>>> 1/2 # , but a strong wind requires that 8# test.
>>> The current will likely be a max of 1/2 amp.
>>
>> Hello,
>> you might need a combination of steel wire for tensile strength and
>> copper wire for low resistance to the electric current. To keep the
>> weight low, replace copper with aluminium.
>> Bye
>
> Hi
> We did an experiment yesterday, we connected a AWG 36 wire
> in series with a 100W bulb, dimmer and Current meter.
> (The AWG 36 wire was carefully wrapped around a couple of
> 3/16" bolts and carefully snugged with nuts, a poor man's fuse).
>
> As we turned up the dimmer we expected the wire to fuse but it
> didn't, it took the full current supplying a 100W bulb, I kid you not,
> that's about 0.9 amps!
> We got the wire from unwrapping a reed switch and checked the
> gauge twice by tensile strength.
> I invite anyone else to try the experiment.
> Regards
> Ken
>
If you're brave, try it with carbon fibre.
--
Dirk
http://www.transcendence.me.uk/ - Transcendence UK
http://www.blogtalkradio.com/onetribe - Occult Talk Show
Nunya
wrote:
Silk strands with old fashioned Bell wire "ribbon wrap".
They probably use Rayon. Remember that wire?
Also used for speaker coil attach wires.
Uwe Hercksen
Ken S. Tucker schrieb:
> As we turned up the dimmer we expected the wire to fuse but it
> didn't, it took the full current supplying a 100W bulb, I kid you not,
> that's about 0.9 amps!
Hello,
a thin wire is able to carry a high current if it is well cooled. But
you will loose some voltage.
Bye
JosephKK
<spef...@interlogDOTyou.knowwhat> wrote:
>On Fri, 30 Jul 2010 19:01:37 -0700 (PDT), the renowned "Ken S. Tucker"
><dyna...@vianet.on.ca> wrote:
>
>>I've been asked to 'light-up' aircraft models, such as,
>>
>>http://www.flickr.com/photos/35156618@N03/4754110575/
>>
>>It is suspended from a rope.
>>I need to use very fine 120V wire (like magnetic wire),
>>the model uses 8# test monofilament right now and weighs
>>1/2 # , but a strong wind requires that 8# test.
>>Is there a table that gives wire gauge & tensile strength?
>>The current will likely be a max of 1/2 amp.
>>Ken
>
>You can pick the material and look up the yield strength.
>
>In Imperial units, maybe steel wire (like music wire) you could use
>300,000 PSI, say.
>
>So for something that would break at 20lbs you would need
>7E-5 in^2, which is about 0.01" diameter, if I did the sums correctly.
>
>You should calculate and test the strength and self-heating effect
>before using it, of course.
>
>
>Best regards,
>Spehro Pefhany
OK. diameter for wire gauges found here:
http://www.interfacebus.com/Copper_Wire_AWG_SIze.html
Yeild strength for several alloys can be found here:
http://www.copper.org/resources/properties/144_8/144_8.html
Using 60,000 psi for yeild strength we want 30,000 or 40,000 psi for
test strength. Thus to get 8 lb test we need 8/30,000 ~= 266 E-6
square inches. Solved for diameter D=sqrt(A/(2*pi)) for
A=sqrt(266/6.28) about 6.5 mils. Thus from the table, 2 #39 enameled
magnet wire lightly twisted ought to provide the mechanical strength
needed and a complete circuit and handle 18 mA without trouble.
JosephKK
<dyna...@vianet.on.ca> wrote:
>On Jul 31, 12:52 am, "Tim Williams" <tmoran...@charter.net> wrote:
>> "Joe" <j...@somewhere.org> wrote in messagenews:i30cnt$d59$1...@news.eternal-september.org...
>> > Numbers in the ARRL handbook chart of breaking load for copper
>> > antenna wire work out to about 39000 psi for soft drawn copper
>> > wire and 65000 psi for hard drawn so perhaps use 2 strands of
>> > varnished #24 or #26 copper magnet wire. Those strength numbers
>> > are higher than Tim mentioned so run deadweight tests before
>> > testing with model.
>>
>> 65 KSI is close to the ultimate tensile strength I saw; I specified yield strength, which is a little lower of course.
>>
>> The yield of dead soft copper is astonishingly low, it's like shiny pink clay. Only that, after you push it around a bit, it hardens up, and pretty soon it's so damn strong you can't bend it by hand anymore! Copper provides a particularly dramatic illustration of work hardening.
>
>This is a Good thread Gents, good of yo'all to be interested.
>To Recap,
>The models will be hung ~5' , the spec is to use 120V 5W & 7W
>xmas bulbs, although I can run a 3rd line for 12V sissy lamps.
>(Gnd, 120V, 12V).
>
>Using this ref
>http://en.wikipedia.org/wiki/American_wire_gauge
>I find 24 AWG to be ok. I used a Yield Tensile Strength of
>Copper ~10,000psi, calculated area and found it to be ~4#.
>(24 AWG has a dia 0.02" )
>Two wires gives a strength of 8# for the Gnd & 120V, and the
>ohm loss calculated for 10'.
>Regards
>Ken
>
>
I got to much finer wire #39. But have a current limit (~18 mA) that
nearly forces an all LED solution.
JosephKK
200 lbs for 2 #24 alloy wire is not unreasonable when i checked it.
you have 32 times the cross section and about twice the strength of my
2 #39 meduim drawn copper solution.
JosephKK
That's why i went for much finer wire, 2 #39 enameled, complete with a
very low current limit ~18 mA.
JosephKK
Alas, the temperature rise on the wire is far more than i care for. I
get over 200 C. That could be enough to cause problems with plastics.
Tim Williams
news:mj9l56dc2in9dj0qv...@4ax.com...
> Solved for diameter D=sqrt(A/(2*pi))
Just pi. But since it's diameter, not radius, it's 2*sqrt(A/pi).
Tim
--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms
Spehro Pefhany
AFAIUI, usually "x pound test" mono line has an actual typical
breaking point 20-100+% higher than x, so more safety margin might be
required.
Nunya
Copper also becomes a bit more 'elastic' as temps go up.
Batteries and LEDs and use the wire to operate a trickle charger
for the batteries. Take the wires off between photo sessions.
That way, you can go back to high tensile strength, fine
gauge piano wire, which has been specifically crafted to
endure tensile force. Paint it neutral gray, if needed.
JosephKK
<spef...@interlogDOTyou.knowwhat> wrote:
Gosh, i am at 50% of _yeild_ strength already. Do you really think i
need more margin?
Ken S. Tucker
I received a lot of good ideas in this thread, what I'm doing now is
sourcing wire suppliers, there are very few in BC, would you guys
have a Canuck outlet that has a good selection?
Ken
Nunya
PIANO wire.
There are also mil spec wire out there, specifically
meant to take tensile forces. With one of those, you could go
even smaller gauge and make it virtually invisible.
Ken S. Tucker
This model is suspended by two 6# test monofilament lines
with 2x 44 gage wires, supplying 18x 1W 2.5V xmass lamps,
http://www.flickr.com/photos/35156618@N03/4923486492/
It pushes the edge of voltage drop over ~ 8' of the wire.
Ken