Ian Stirling wrote:

In sci.electronics.design Albert wrote:


Does anyone know how to measure or determine the wire size. I have
tons of motors, solenoids, and similar items. I need some #24 wire and
some #30 for a coil, but have to be sure regarding the wire diameter
as it's a critical ap and the author of the article says 'don't
substitute'.



Micrometer.
Vernier caliper may also work.
Either under $30US.


And don't forget to remove any insulation before measuring the wire.

Bill K7NOM

"Albert" bravely wrote to "All" (07 Apr 05 17:29:15)
--- on the heady topic of "wire size question"

Al From: Albert
Al Xref: aeinews sci.electronics.design:8716
Al sci.electronics.components:12978 rec.radio.amateur.homebrew:9183

Al Does anyone know how to measure or determine the wire size. I have
Al tons of motors, solenoids, and similar items. I need some #24 wire and
Al some #30 for a coil, but have to be sure regarding the wire diameter
Al as it's a critical ap and the author of the article says 'don't
Al substitute'.
[,,,]
Al Perhaps a milliohm meter might be able to measure the difference in
Al resistance of a foot of it or so, but that's hardly a standard item
Al either.

A practical answer: measure the resistance of a known length of wire.
You don't need a milli-ohmmeter to do this. Simply inject an accurate
current into a known length of wire, let's say for example 1 ampere.
Then use a dmm on the 200mv range to measure the voltage drop. This
gives a direct reading of milliohms x feet. Multiply this value up to
a range of 1,000 ft and look it up on a standard wire table and read
the gauge column. That's it! No fussing with diameters or micrometers,
microscopes or conductivity. One note of caution: if the wire glows,
the current is too large!

A*s*i*m*o*v

.... ... Clavicula .. Rectus abdominus .. Corpus sterni .. Piramidalis

I read in sci.electronics.design that Albert wrote (in
) about 'wire size
question', on Thu, 7 Apr 2005:

Does anyone know how to measure or determine the wire size.

Use a micrometer or a vernier slide gauge to measure the diameter.
Assuming that your wire is enamelled, 24 AWG is 0.022 inch (maybe +/-
0.002) diameter and 30 AWG is 0.011 inch diameter.
--
Regards, John Woodgate, OOO - Own Opinions Only.
There are two sides to every question, except
'What is a Moebius strip?'
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

I read in sci.electronics.design that Reg Edwards
wrote (in
) about 'wire size question', on Thu,
7 Apr 2005:
Which gauge are you using?

British Standard wire gauge (SWG) ? American wire gauge (AWG) ?
Birmingham wire gauge (BWG) ?

Malt vinegar gauge - brown and sharp. (;-)
--
Regards, John Woodgate, OOO - Own Opinions Only.
There are two sides to every question, except
'What is a Moebius strip?'
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

In sci.electronics.design Ross Herbert wrote:
On Thu, 07 Apr 2005 23:21:40 GMT, Bill Janssen
wrote:

Ian Stirling wrote:

In sci.electronics.design Albert wrote:


Does anyone know how to measure or determine the wire size. I have
tons of motors, solenoids, and similar items. I need some #24 wire and
some #30 for a coil, but have to be sure regarding the wire diameter
as it's a critical ap and the author of the article says 'don't
substitute'.

Micrometer.
Vernier caliper may also work.
Either under $30US.

And don't forget to remove any insulation before measuring the wire.

Correct Bill. However DO NOT scrape the insulation from the wire since
this can alter the physical diameter of the wire. It is best to dip a
portion of the wire in fast acting paint stripper and wipe the
softened insulation off with a rag.

Blowtorch to heat to dull red heat, and then wipe insulation off.

Albert wrote in message ...
Does anyone know how to measure or determine the wire size. I have
tons of motors, solenoids, and similar items. I need some #24 wire and
some #30 for a coil, but have to be sure regarding the wire diameter
as it's a critical ap and the author of the article says 'don't
substitute'.

Any suggestions?

Thanks,

A

Well.... ignoring other things..... perhaps you'd like to explain why it's
so critical or give a link to the article.

DNA

I read in sci.electronics.design that Ian Stirling
wrote (in
) about 'wire size
question', on Fri, 8 Apr 2005:

Blowtorch to heat to dull red heat, and then wipe insulation off.

I'd like to see you do that with 30 gauge wire. For an encore, you could
do it with 46 gauge. (;-)
--
Regards, John Woodgate, OOO - Own Opinions Only.
There are two sides to every question, except
'What is a Moebius strip?'
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

From: "Henry Kolesnik" on Thurs,Apr 7 2005 10:15 pm

Get a nice piece of smooth round rod and tightly wind a little over a
lineal
inch of wire closely spaced as possible. Count the turns in one inch
and
divide the number of turns into one inch and you'll have a very good
measurement without any cost.

73
Hank WD5JFR

Albert wrote in message
...
Does anyone know how to measure or determine the wire size. I have
tons of motors, solenoids, and similar items. I need some #24 wire
and
some #30 for a coil, but have to be sure regarding the wire diameter
as it's a critical ap and the author of the article says 'don't
substitute'.

I know I can weigh it, provided it's not on a spool or motor winding
already.

My local electrical shop has a wire gauge, but it stops at 18 gauge.

A microscope might work, but ones that have calibrated distance
measuring on the eyepiece are expensive.

Perhaps a milliohm meter might be able to measure the difference in
resistance of a foot of it or so, but that's hardly a standard item
either.

Any suggestions?

A non-destructive measurement is best. Along about
1946 my middle school (we called it "junior high" back
then) electric shop instructor demonstrated how to use
a mechanical caliper and how NOT to squeeze too hard in
doing so. Soft-drawn copper common to wire is fairly
easy to squash when using a caliper. Using one requires
a VERY light touch on the wire, just enough to be able
to pull it slightly through the caliper jaws. Even so,
pulling on soft-drawn copper wire is going to distort it
slightly so the measurement is going to be on the small
side. Snipping off ten or twenty short lengths, then
measuring the total width and dividing by the number of
lengths will be a bit better in accuracy.

A pocket optical comparator is handy for this and other
uses, especially when trying to get a measurement on
something already mounted with epoxy, varnish, etc. as
in windings of electric motors. While the "100-foot
resistance test" is a practical idea with a roll of
wire, it is hard to do when the wire comes from a
motor or transformer giving its all to the project.

As a practical matter, the wire size in small (such as
HF range) coils won't matter much on either the
inductance or Q tolerance. For example, Dropping from
30 AWG to 32 AWG isn't going to be a disaster in
cylindrical ("solenoidal") or toroidal forms. The
change in inductance will be aligned-out on trimming
in the circuit itself. Q is going to change much more
depending on the material of the coil former and the
presence of nearby conductive objects such as shields.

If a Twenty is too much for a pound or so of new wire
stock, then nobody can afford a Q Meter or inductance
meter to do an accurate measurement. Get with some
friends/acquaintences and share the cost of new stock.

Just some practical thoughts after doing a bit of
winding in my time...

In sci.electronics.design John Woodgate wrote:
I read in sci.electronics.design that Ian Stirling
wrote (in
) about 'wire size
question', on Fri, 8 Apr 2005:

Blowtorch to heat to dull red heat, and then wipe insulation off.

I'd like to see you do that with 30 gauge wire. For an encore, you could
do it with 46 gauge. (;-)

Actually, I do it regularly with .15mm wire (I don't know the guage)
Of course, you have to be able to set the blowtorch so that it's producing
a yellow flame that's not too hot, a lighter works well.

On 08 Apr 2005 20:00:02 GMT, Ian Stirling
wrote:

In sci.electronics.design John Woodgate wrote:
I read in sci.electronics.design that Ian Stirling
wrote (in
) about 'wire size
question', on Fri, 8 Apr 2005:

Blowtorch to heat to dull red heat, and then wipe insulation off.

I'd like to see you do that with 30 gauge wire. For an encore, you could
do it with 46 gauge. (;-)

Actually, I do it regularly with .15mm wire (I don't know the guage)
Of course, you have to be able to set the blowtorch so that it's producing
a yellow flame that's not too hot, a lighter works well.

IIRC there's something called Formvar that will self-strip upon
application of a tinned iron.

There's also the chemical stripping agents.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

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