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wire size question

I

Ian Stirling

Jan 1, 1970
0
In sci.electronics.design John Woodgate said:
I read in sci.electronics.design that Ian Stirling


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.
 
J

Jim Thompson

Jan 1, 1970
0
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
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that Ian Stirling
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.

Oh, that's cheating. (;-) When you write 'blowtorch', you should mean
'blowtorch', 1000 C plus.

The almost cool flame of an alcohol burner is good, especially as it has
a large part of its volume that is chemically reducing.
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that Jim Thompson
IIRC there's something called Formvar that will self-strip upon
application of a tinned iron.

Once upon a time, there was 'flux-enamelled' magnet wire, which was
really easy to solder, but the coating was fragile. Then there was
'solderable', which required an iron temperature substantially higher
than for normal soldering. But that gave off toluene diisocyanate, which
is poisonous if you breathe it for 20 years, so you had to use it under
extraction, and that made it fall out of favour.
 
W

Watson A.Name - \Watt Sun, the Dark Remover\

Jan 1, 1970
0
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?

I use either a dial calipers or a micrometer. But then the insulation
can make it sizeably larger than the value given in the wire tables.
The wire tables have a column which gives 'ohms per 1000 ft' which is
just another way of saying milliohms per foot. So if you measure ten
feet of 30 AWG it should measure 1.04 ohms. My cheap meter test leads
are something like .4 ohms, so it's really difficult to get any accuracy
at that low a resistance. I have a Leeds Northrup wheatstone bridge,
and it's not very good either at that low a resistance. So I put the
wire or whatever on a power supply and crank up the current to a quarter
amp, and then measure the V drop and calculate the resistance from that.
 
W

Watson A.Name - \Watt Sun, the Dark Remover\

Jan 1, 1970
0
Ian Stirling said:
Micrometer.
Vernier caliper may also work.
Either under $30US.

I don't believe anyone uses vernier calipers anymore. I've got a Helios
dial caliper made a long time ago in Deutschland, but nowadays a caliper
with a LCD is probably a lot cheaper.
 
W

Watson A.Name - \Watt Sun, the Dark Remover\

Jan 1, 1970
0
Dave Platt said:
A cautionary note - if it's that critical, then re-using wire which
has alread been wound might not be the best idea. You'd be starting
with wire which had already been bent/flexed, and if you aren't
careful this might put some kinks or irregularities in the winding of
your new coil which might affect its impedance or Q.


You might be able to do it with a vernier caliper.

24 gauge has a diameter of .511 mm or .0020"

30 gauge has a diameter of .255 mm or .001"

Man, are you _way_ off! By an order of magnitude! Put your glass on
and reread the wire tables.
 
P

Peter A Forbes

Jan 1, 1970
0
I don't believe anyone uses vernier calipers anymore. I've got a Helios
dial caliper made a long time ago in Deutschland, but nowadays a caliper
with a LCD is probably a lot cheaper.

I do, got fed up with resetting the mechanical dial type through the rack and
pinion becoming dirty, and electronics/robustness issues with electronic types.

Peter
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that "Watson A.Name - \"Watt Sun, the
I don't believe anyone uses vernier calipers anymore. I've got a
Helios dial caliper made a long time ago in Deutschland, but nowadays a
caliper with a LCD is probably a lot cheaper.

In UK, you can get vernier calipers for around GBP1 (and mine check out
as quite sufficiently accurate). LCD calipers are about GBP35.
 
W

Watson A.Name - \Watt Sun, the Dark Remover\

Jan 1, 1970
0
From: "Henry Kolesnik" on Thurs,Apr 7 2005 10:15 pm


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.

HUH? What do you mean, Jellybean?

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

Uh, yeah...
 
P

Pooh Bear

Jan 1, 1970
0
Watson A.Name - \"Watt Sun said:
I use either a dial calipers or a micrometer. But then the insulation
can make it sizeably larger than the value given in the wire tables.
The wire tables have a column which gives 'ohms per 1000 ft' which is
just another way of saying milliohms per foot. So if you measure ten
feet of 30 AWG it should measure 1.04 ohms. My cheap meter test leads
are something like .4 ohms, so it's really difficult to get any accuracy
at that low a resistance. I have a Leeds Northrup wheatstone bridge,
and it's not very good either at that low a resistance. So I put the
wire or whatever on a power supply and crank up the current to a quarter
amp, and then measure the V drop and calculate the resistance from that.

I use that trick too. The only sensible way to measure a coil's winding R.

Graham
 
P

Pooh Bear

Jan 1, 1970
0
Watson A.Name - \"Watt Sun said:
I don't believe anyone uses vernier calipers anymore. I've got a Helios
dial caliper made a long time ago in Deutschland, but nowadays a caliper
with a LCD is probably a lot cheaper.

Ohhh... I assumed anyone serious would be using a Mitotuyo ? digital LCD
vernier caliper anyway. We certainly have one.


Graham
 
S

Spehro Pefhany

Jan 1, 1970
0
I read in sci.electronics.design that "Watson A.Name - \"Watt Sun, the


In UK, you can get vernier calipers for around GBP1 (and mine check out
as quite sufficiently accurate). LCD calipers are about GBP35.

You can get low-end LCD calipers in the US for the equivalent of about
GPB8 plus tax. For GPB1 (<$1.99) I think you'd get some stamped or
plastic item that would only be good to 0.01".


Best regards,
Spehro Pefhany
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that Spehro Pefhany
You can get low-end LCD calipers in the US for the equivalent of about
GPB8 plus tax. For GPB1 (<$1.99) I think you'd get some stamped or
plastic item that would only be good to 0.01".

No, they are metal, and claim to measure to 0.001 inch, 0.02 mm. I've
checked mine against a good micrometer and it's as accurate as I can
read the vernier. YCCMV, of course.
 
W

Watson A.Name - \Watt Sun, the Dark Remover\

Jan 1, 1970
0
John Woodgate said:
I read in sci.electronics.design that "Watson A.Name - \"Watt Sun, the


In UK, you can get vernier calipers for around GBP1 (and mine check
out

For that cheap, you probably get plastic!
http://www.widgetsupply.com/page/WS/PROD/caliper-vernier/BET07
as quite sufficiently accurate). LCD calipers are about GBP35.

These look like a good deal on your side of the pond.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=20766&item=436984
3430&rd=1
 
M

Michael

Jan 1, 1970
0
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.
(snip)

Really? Hmmmm ...
 
G

Gary S.

Jan 1, 1970
0
I read in sci.electronics.design that "Watson A.Name - \"Watt Sun, the


No longer there.

The link was too long and got broken.

Much better to enclose all links in <> brackets, which will still work
right even if split/word-wrapped into multiple lines. Works with all
of the browsers I have used.

For example:
<http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=20766&item=4369843430&rd=1>
for the item above, which works as Watson intended.

There are also options like tinyurl, but some do not trust that.

Happy trails,
Gary (net.yogi.bear)
 
W

Watson A.Name - \Watt Sun, the Dark Remover\

Jan 1, 1970
0
Pooh Bear said:
that.

I use that trick too. The only sensible way to measure a coil's
winding R.

Long as it doesn't start glowing red. ;-)

Probably not such a good idea for measuring the series R of inductors.
Unless you run a Hi Power tape demagnetizer over it when you're done..

BTW, speaking of tapes.. I read that the company that made Irish and
Ampex tape has closed. Looks like everyone has been going to CD-Rs.

http://members4.boardhost.com/culturama/msg/3217.html
 
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