Flexible wires needed

[Iain]

https://www.digikey.com/products/en/cables-wires/single-conductor-cables-hook-up-wire/474


Here's 100' of 32 AWG with an OD of 0.015".

[jeffstri]

usually the wires with more conductors [ and more flexible] do have a reduced amperage rating ..

Wire with more conductors (i.e., strands) for a given gauge (awg) has the same voltage/amperage rating as a solid single conductor wire. Stranded wire is thicker overall, mainly because of air space between the strands.

According to a calculator on the Engineering Toolbox site, a 36-gauge wire at 12v carrying 1 amp is good for 5 feet.  .24v drop at the 5-foot length.

I think you may have used the diameter rather than cross sectional area for 36awg wire. For 36awg at 12v/1amp, I calculate the voltage decrease to be 0.24v at about 7 inches; for 29awg at 12v/1am, a decrease of 0.24v occurs at 3.9 feet.

All "super"and "ultra" flexible wires are not the same. What's important for connecting a steam engine and tender is continuous flexibility, the ability to tolerate repeated back and forth bending. The more strands, the more flexible, but flexibility also depends on the insulation. The "super-flexible" wire Ngineering sells has silicone insulation and is as limp as a rubber band - much more flexible than any PVC insulated wire. I use the 29awg between steam engines and tenders with decoders, up to 6 wires between them with no problems on sharp curves.  I've found a number of other sources for the same wire (e.g., MacMaster-Carr, item 9564T2), but right now the Ngineering price per foot is better.

You can't strip silicone insulation with a hot soldering iron, which can be an advantage because you can't burn off too much insulation when you solder. You can use your fingernails, but I use an Ideal 45-125 stripper at the 26awg setting. I rarely lose a strand if I position the wire in the stripper under magnification.

[peteski]

. . .
 The "super-flexible" wire Ngineering sells has silicone insulation and is as limp as a rubber band - much more flexible than any PVC insulated wire. I use the 29awg between steam engines and tenders with decoders, up to 6 wires between them with no problems on sharp curves.  I've found a number of other sources for the same wire (e.g., MacMaster-Carr, item 9564T2), but right now the Ngineering price per foot is better.

You can't strip silicone insulation with a hot soldering iron, which can be an advantage because you can't burn off too much insulation when you solder. You can use your fingernails, but I use an Ideal 45-125 stripper at the 26awg setting. I rarely lose a strand if I position the wire in the stripper under magnification.

Or if you have HOTWEEZERS stripper at your disposal, it gets hot enough for stripping  silicone insulation. 

I have 2 types of the flexible wires from N-gineering and I don't recall either having silicone insulation.  But I bought those about 10 years ago. I have to check them out again.

[jdcolombo]

@jeffstri

Yep,  you're right.  I was using diameter instead of cross-section.  Still, I've had no ill effects from using ESU's 36-gauge decoder wire as connection wire from boiler to tender.  I guess this is due to the fact that (1) wire runs are still very short, usually less than 3" one way (6” total circuit) and (2) we're not actually drawing anywhere close to 1 amp in a modern N scale engine.  The highest amperage draw I've measured on one of my N-scale engines at stall is about .6 amp (a Hallmark brass GP9), and in fact our engines never stall - they slip the drivers instead.  Normal current draw is 1/3 amp or less.

But I agree that the Ngineering superflex wire is excellent for boiler-tender connections.  I used some of it in one of my Berk installs, and it has zero adverse effects on that Berk on my narrowest (14" radius) curves.  I mostly gravitated to the ESU decoder wire because I have a lot of it for decoder installations.

John C.

[reinhardtjh]

And now Peteski has me eyeing a $500 wire stripper!

These are a little cheaper...

For those interested, there are several sets of HOTweezers available now on Ebay for around $120 plus shipping.

Meisei M10 Power Supply w/ 4A / 7A Hotweezer Lot A Non-ESD with the small wire size tweezers

Meisei M10 Power Supply w/ 4A Hotweezer Lot C  Non-ESD with the small wire size tweezers

Meisei M10 Power Supply w/ 7A Hotweezer Lot E  Non-ESD (even thought the 7A is supposed to e ESD) with the small wire size tweezers

Meisei M10 Power Supply w/ 7C Hotweezer Lot D Non-ESD with the straight blade tweezers.  Would those still work if you were careful not to pinch too hard?

There are also a number of actual 7C (ESD) HOTweezers for the M-20 P/S for $80 but the M-20 P/S picking s are so-so, ranging from $40 parts units (needing repairs) to $500 (must be gold plated inside).

[mmagliaro]

I strip this fine wire by placing the end of the wire on a flat piece of metal or glass, just touch the end with a hot soldering iron tip to the insulation and pull, and it will melt and pull off the wire cleanly.  Then tin the exposed end with a drop of solder on the tip of the iron to burn away and junk left on the wire and tin it.  It makes a minor mess on the iron tip, but nothing that doesn't wipe right off on the wet soldering iron sponge.

[peteski]

I strip this fine wire by placing the end of the wire on a flat piece of metal or glass, just touch the end with a hot soldering iron tip to the insulation and pull, and it will melt and pull off the wire cleanly.  Then tin the exposed end with a drop of solder on the tip of the iron to burn away and junk left on the wire and tin it.  It makes a minor mess on the iron tip, but nothing that doesn't wipe right off on the wet soldering iron sponge.

Sure, there are many creative ways to strip stranded wire without damaging the strands, but having a good stripping tool also helps.
I sometimes install a wired decoder which is covered with heat shrink, and to do a neat wiring job some of the pigtail wires coming out of the decoder are less than 1/4" long. the HOTTWEEZER is a perfect way to strip those. 

And if one is patient, like John pointed out, they do show up on eBay regularly and can be had for much less than hundreds of dollars.