Flexible wires needed

[porkypine52]

Head up to your local RECYCLING DROP OFF CENTER.  See if they have any dead [recycled] computer CPU's.  A dead desktop unit will do fine.  Open the thing up, and find all different sizes of wire inside.  You don't care if the CPU works or not.  All you want is wiring.

[jdcolombo]

I didn't cite any specific numbers in my recommendation - just my overly cautions "gut feeling" about 36AWG wire.

John, where did you find the info you cited?
I looked at https://www.engineeringtoolbox.com/amps-wire-gauge-d_730.html and https://www.engineeringtoolbox.com/wire-gauges-d_419.html and didn't find current ratings for 36AWG wire.  I went elsewhere and found some info.

Hi Pete.

I used the following calculator:

https://www.engineeringtoolbox.com/12-volt-wire-loss-chart-d_1689.html

It's not an ampacity chart, but rather a maximum wire length calculator for a 2% voltage drop at a given amperage (I used 1 amp) and wire size in square mm (36-gauge wire is .127 square mm thick). 

Fusing current of 3.62 amps for 36-gauge wire is shown in this table:

https://www.powerstream.com/wire-fusing-currents.htm

As you know (but maybe others don't) whether a given wire is "safe" for a given load depends mostly on its resistance.  The resistance is what causes heat as a particular load passes through the wire.  The longer the wire and the smaller the gauge, the more resistance there is, until heat buildup melts the insulator and causes a fire.  Very short lengths of even tiny-gauge wire can carry significant amperage loads; it's just a question of the load vs. resistance (wire size and length) vs. heat generated. 

I've used ESU's 36-gauge decoder wire in HO installations, but never in lengths longer than 4 inches.  You obviously wouldn't want to use it as DCC buss wire, or even as feeder wire to a track segment where it is carrying the full 5-amp load of the booster.  But for wiring a few inches in a 1-amp decoder, it should be absolutely fine.   When you think about it, tiny PC board traces carry very significant currents in virtually all electronics equipment.  The trace is short, the ground plane (return part of the circuit) is usually quite large, and that means there isn't much chance of melting the trace.

John C.

[jdcolombo]

BTW, in case folks are wondering why I used a voltage-loss calculator, the answer is heat.

A voltage drop of .24v at 1 amp of current represents 240mw of power consumption.  That 240mw is converted to heat.  You can calculate the temperature rise in a piece of wire or electrical component if you know the power consumption and thermal resistance of the component involved.  But 240mw isn't much; it's what a 1/4-watt resistor dissipates in heat (although to be fair, resistors can get pretty darn hot).  And remember, this would be for a nearly 6-foot length of that wire (according to the calculator).

A six-inch length of 36-gauge wire in a 12v circuit carrying 1 amp would have a voltage drop of about .024v, representing 24mw of power (not 240, but 24).  That's negligible, and in turn means there basically isn't much heat being generated across that length of wire.  No heat = no danger of melting the insulation, which in turn means the wire is perfectly safe for use.

John C.

[bbunge]

Ok if I hijack this thread for a second since there seems to be plenty of answers to ask a dumb question.  How do you all strip this type of wire without cutting any of the strands?

Thanks,

Bob

[Steveruger45]

Ok if I hijack this thread for a second since there seems to be plenty of answers to ask a dumb question.  How do you all strip this type of wire without cutting any of the strands?

Thanks,

Bob

If you mean stripping the end of insulation off to expose the conductors for tinning, I use one of several different techniques depending on the insulation, including using my thumb nail to pinch and pull, or scrape with a knife or heat from an old soldering iron I have relegated to this use.  There are wire strippers too but I don’t have any for such small wire.

I’m sure others will chip in here too

[jdcolombo]

Ok if I hijack this thread for a second since there seems to be plenty of answers to ask a dumb question.  How do you all strip this type of wire without cutting any of the strands?

Thanks,

Bob

Pinch the wire between my thumbnail and forefinger and pull.  I also have a small pressure-sensitive wire stripper that works, but I find myself using the thumbnail/forefinger approach all the time.  The insulation comes off the ESU decoder wire pretty easily with the right pincer movement.  General Patton would be proud.

John C.

[carlso]

mike_lawyer,

I too have purchased some of both the 29 & 32 sizes but have not used either yet. My idea is to add a decoder to a couple of Key lokies as well as some old Atlas/Kato diesels. Which size have you used and been happy with.

Appreciate your input,
Carl

[mike_lawyer]

I think it was the number 32 wire.  It is whatever Ngineeering sells as the "superflexible wire."  I have used that for transferring tender power to motors and so forth with great success.  I have not used it for decoders, though.

[peteski]

Thanks for the info John.  Yes, the voltage drop and the resistance are the key in wiring safety.  I rather be safe than sorry, but the calculations don't lie.

I might as well address some other things mentioned in this thread.

Utilizing wire from broken electronic devices (like computers) is ok, but in my was experience in doing just that, I have never found the type of fine stranded and *VERY* flexible wire (that is needed for N scale loco-to-tender connection) in any computer. While some wires (especially in the ribbon cables) are quite fine, they are way too stiff for what I need them for.  The tonearm wire John mentioned woudl probably be the only usable wire from recycled electronics. And I have taken them all apart at one time or another.  What is very usable in those devices are all sorts of c=solenoids. Those are great source for very thin enameled magnet wire.  Also , many electronic components make good detail or "junk" items for N scale railroads.  By I digress.

Stripping fine stranded wire without nicking the strands is a big problem.  I used to put the wire against the hot soldering iron tip (perpendicular to it) and spin it around to basically melt or burn a ring of insulation. Hot stripping.  Then the  the insulation can be easily removed by pulling on it.
I now almost exclusively use a stripper that uses the same process, but it is designed for the job.

It is called HOTWEEZERS and it consists of a tweezer-like stripper with electric heater built in and a base unit is an adjustable power supply that controls the stripping temperature.  Basically this is the same process I used to perform with my soldering iron, but much more precise.

I adjust the temperature to be just hot enough to soften the insulation (if it is too hot, it will melt it and make mess).  Then Iclose the stripper's jaws around the stripping point and pull the insulation off. Very quick and easy, and the strands do not get nicked.

HOTWEEZERS is an industrial tool - very expensive. I got mine on eBay for fraction of its retail price.  There are multiple handpieces available, for a wide range of wire gauges. I have couple, which handle wire 36 AWG to around 14 AWG.

For more info see the main site https://meiseitools.com/ (or the reseller http://www.meiseihotweezers.com/ ) and see if you can find a used unit on eBay or other surplus suppliers.  Once you try this unit, you will never go back to the conventional wire strippers.

I own the M-10 base unit/power supply and 4A and 4B handpieces (4A is the only one really needed for thin gauge wires).

[jdcolombo]

. . .

It is called HOTWEEZERS and it consists of a tweezer-like stripper with electric heater built in and a base unit is an adjustable power supply that controls the stripping temperature.  Basically this is the same process I used to perform with my soldering iron, but much more precise.

I adjust the temperature to be just hot enough to soften the insulation (if it is too hot, it will melt it and make mess).  Then Iclose the stripper's jaws around the stripping point and pull the insulation off. Very quick and easy, and the strands do not get nicked.

HOTWEEZERS is an industrial tool - very expensive. I got mine on eBay for fraction of its retail price.  There are multiple handpieces available, for a wide range of wire gauges. I have couple, which handle wire 36 AWG to around 14 AWG.

For more info see http://www.meiseihotweezers.com/  and see if you can find a used unit on eBay or other surplus suppliers.  Once you try this unit, you will never go back to the conventional wire strippers.

Uh-oh.  Pete's going to get me interested in another high-end tool.  I never knew such a thing existed.  Very cool (well, technically, I guess very hot) - and it looks like Hakko and others make something similar, but they all are about $450.  Still, I strip a LOT of 36-gauge wire . . .

John C.

[peteski]

Uh-oh.  Pete's going to get me interested in another high-end tool.  I never knew such a thing existed.  Very cool (well, technically, I guess very hot) - and it looks like Hakko and others make something similar, but they all are about $450.  Still, I strip a LOT of 36-gauge wire . . .

John C.

LOL!  Right tool for the job, makes the job easier and fun! 
Where this tool really shines is when you have very short pieces of wire to be stripped in close quarters.  The HOTWEEZERS stripping head is very small, so it can strip even under those condition. Places that no conventional stripper could be used.

Like I said, look in eBay (set up an automatic search).  They come up for sale from time to time, at surplus prices.  That's how I got mine.  Even if you only find the tweezers handpiece, we can talk - I have some spare base units. 

[reinhardtjh]

Uh-oh.  Pete's going to get me interested in another high-end tool.  I never knew such a thing existed.  Very cool (well, technically, I guess very hot) - and it looks like Hakko and others make something similar, but they all are about $450.  Still, I strip a LOT of 36-gauge wire . . .

John C.

There are some much cheaper prices on Ebay ( just looked...  I love tools and gadgets)

Edit:  The power units are relatively cheap. The tweezers are wicked expensive.   

Looks like it's the 4A tweezers that are the right wire gauge for us.

[peteski]

There are some much cheaper prices on Ebay ( just looked...  I love tools and gadgets)

Edit:  The power units are relatively cheap. The tweezers are wicked expensive.   

Looks like it's the 4A tweezers that are the right wire gauge for us.

That is because the power unit is just a transformer and couple of other components. The tweezers appear to be all hand-made (not done on an assembly line).  It is a very impressive tool.  Basically stainless steel tweezers with hollow jaws containing tiny heater elements.  If set to full power the jaws actually get hot enough to glow red.  At that temperature, they will even strip Teflon and Silicone insulation.

And yes, 4A is the handpiece you need for small gauge wires.

[Lemosteam]

@peteski The handpiece I'd be most interested in is an opposed spread handpiece (when squeezed the elements open instead of closed- reverse action tweezers, I think) so you could separate the insulation mid-wire for a splice joint, such as tapping into a bus wire.

[peteski]

@peteski The handpiece I'd be most interested in is an opposed spread handpiece (when squeezed the elements open instead of closed- reverse action tweezers, I think) so you could separate the insulation mid-wire for a splice joint, such as tapping into a bus wire.

HOTWEEZER unit only has 4 handpieces available: 2 for stripping various gauge wires, one with no notches for wire, and a hot knife.

I also can't picture how the one you want would work.  Maybe the hot knife could be used to melt the insulation along the wire, sit it can then be spread open and removed.  But for that you don't need an expensive thermal stripper.  There are craft-type hot knives available for much less money (basically a low-end soldering iron with a knife instead of a soldering tip).

I actually do this type of wire stripping using a regular soldering iron.