These are the type of strippers we use at work:
Ideal Custom Stripmaster Wire Stripper for Aircraft Teflon Wire
They aren't too cheap though.
I tend to hold a blade on the wire and roll it until I get to the core then use normal strippers placed at the cut point to remove the end. It takes time and is a pain but works for me.
I'd love to hear of a faster way though!
Ideal Custom Stripmaster Wire Stripper for Aircraft Teflon Wire
They aren't too cheap though.
I tend to hold a blade on the wire and roll it until I get to the core then use normal strippers placed at the cut point to remove the end. It takes time and is a pain but works for me.
I'd love to hear of a faster way though!
I like both of these:
ST-500 Jonard Industries | Mouser
and for a bit more:
PTS-30 Patco Services Inc | Tools | DigiKey
Phil
ST-500 Jonard Industries | Mouser
and for a bit more:
PTS-30 Patco Services Inc | Tools | DigiKey
Phil
Take a short read around these pages:
http://www.diyaudio.com/forums/clas...8d2-boards-modding-comes-144.html#post4864915
http://www.diyaudio.com/forums/clas...8d2-boards-modding-comes-144.html#post4864915
I just use the miller strippers now sold by Dorman at the auto supply. <$10. Takes some practice to not nick the wire - but doable. Go around 90 deg first, just squeezing makes 4 cuts, not one. I grip the wire over the insulation with pliers when pulling the strip off, else often the long piece strips off instead of the short piece.
Most of what I use in chassis is solid core 24-28 awg so you've either cut the wire, or not. Even throwing away a few mis-strips, teflon saves me time from not having to replace the bottom wire of 6 on the terminal if I happen to burn PVC insulation off with the iron.
To strip teflon insulated wire, I use a razor blade around the wire against a long noseplier holding the wire. This to make sure it cuts the teflon in only one groove. If the cut is only one groove and all around, pulling will strip easily.
It is a slow way, but the only one I found for a prefectly fine work.
It is a slow way, but the only one I found for a prefectly fine work.
I found a used Teledyne TW-1 on eBay about ten years ago for $65. They are rather pricey new, $294 from the vendor below. You may find them as surplus items.
Teledyne TW-1 StripAll Standard Thermal Wire Stripper Check out the video and PDF.
The TW-1 will strip any size from 38 to 10 AWG and small diameter coaxial cable. It actually melts the teflon and leaves a nice smooth cut without damaging the strands. We used these to meet NASA assembly specs for spacecraft.
I had trouble finding teflon 10 pf caps for the Leach amplifier, I used RG216 small diameter teflon coax. It's about 20 pf per foot, I cut a 6.5" length, using the thermal stripper I stripped 0.5" of outer insulation and 0.375" of inner insulation. I coiled it into a 0.75" diameter loop with a wire tie and replaced the loop bandwidth 10pf Mica capacitor which has high DA and it was an audible improvement, small change but noticeable on good speakers.
Gerold
Teledyne TW-1 StripAll Standard Thermal Wire Stripper Check out the video and PDF.
The TW-1 will strip any size from 38 to 10 AWG and small diameter coaxial cable. It actually melts the teflon and leaves a nice smooth cut without damaging the strands. We used these to meet NASA assembly specs for spacecraft.
I had trouble finding teflon 10 pf caps for the Leach amplifier, I used RG216 small diameter teflon coax. It's about 20 pf per foot, I cut a 6.5" length, using the thermal stripper I stripped 0.5" of outer insulation and 0.375" of inner insulation. I coiled it into a 0.75" diameter loop with a wire tie and replaced the loop bandwidth 10pf Mica capacitor which has high DA and it was an audible improvement, small change but noticeable on good speakers.
Gerold
I use a much older all metal version of the Ideal Stripmaster; telephone company surplus I picked up at a hamfest. About $15 USD, IIRC.
They used to be called lineman's pliers, or something like that. They work well on about anything, including teflon.
Win W5JAG
More strands, less fatigue
Actually, I think it’s exactly the opposite. A wire with a large number of finer strands handles mechanical stress and vibration better than a solid core or a wire with fewer, thicker strands having the same gauge.
https://apps.dtic.mil/dtic/tr/fulltext/u2/656334.pdf
“There appears to be a definite advantage to a large number of fine strands”
Stranded Wire and Solid Wire
“solid wire is not so resistant to vibration and repetitive movement compared to stranded wire”
You can feel the difference in your hands. Finer stranded wires are more flexible than solid core of the same gauge. That flexibility is from the individual strands being able to move and slide, relieving stress. If you bend both types around the same radius, that bend is much more gradual to the finer strands (a smaller percentage of the strands’ diameter). To the solid core, bends create fatigue from compression and tension cycles that create stress fractures. The wire may not come apart but there can be hidden fractures and increasing resistance with repetitive motion.
Actually, I think it’s exactly the opposite. A wire with a large number of finer strands handles mechanical stress and vibration better than a solid core or a wire with fewer, thicker strands having the same gauge.
https://apps.dtic.mil/dtic/tr/fulltext/u2/656334.pdf
“There appears to be a definite advantage to a large number of fine strands”
Stranded Wire and Solid Wire
“solid wire is not so resistant to vibration and repetitive movement compared to stranded wire”
You can feel the difference in your hands. Finer stranded wires are more flexible than solid core of the same gauge. That flexibility is from the individual strands being able to move and slide, relieving stress. If you bend both types around the same radius, that bend is much more gradual to the finer strands (a smaller percentage of the strands’ diameter). To the solid core, bends create fatigue from compression and tension cycles that create stress fractures. The wire may not come apart but there can be hidden fractures and increasing resistance with repetitive motion.
Lots of fine strands in teflon jacket will be very weak as teflon is crystalline at room temperature and very hard, no strain relief to speak of at the interface between jacket and bare strands.
Solid core in teflon is more robust than this just by being stiffer, and multistrand in soft insulation is even more robust by being able to flex without stress concentration.
Basically if nothing exceeds its fatigue limit all is good, otherwise there will be fatigue over time - concentrating stress allows smaller movements to produce fatigue at the point of concentration, stiffening the system reduces the movement for given force which can also protect (ie just use thicker wire).
Solid core in teflon is more robust than this just by being stiffer, and multistrand in soft insulation is even more robust by being able to flex without stress concentration.
Basically if nothing exceeds its fatigue limit all is good, otherwise there will be fatigue over time - concentrating stress allows smaller movements to produce fatigue at the point of concentration, stiffening the system reduces the movement for given force which can also protect (ie just use thicker wire).
Most mil spec wire is crimped and the minute you solder this connection, you don’t know how much wicking travels up the wire beyond the connector and how it stops across the core section.
Flexing at this point will put unequal stress on fine strands over others at different levels and will start to break
The heat from soldering has now also weakened the fine strands just beyond where the solder ended
With crimping only you now have no heat involved and the crimping puts an equal stress across the core section
Crimping is more consistant and offers repeatability over many connections in comparison
The Porsche 917 learned the hard way with soldered connections not that stranded wire is more flexible and durable than solid wire, its the interface connection that takes the hit and how you deal with it
Flexing at this point will put unequal stress on fine strands over others at different levels and will start to break
The heat from soldering has now also weakened the fine strands just beyond where the solder ended
With crimping only you now have no heat involved and the crimping puts an equal stress across the core section
Crimping is more consistant and offers repeatability over many connections in comparison
The Porsche 917 learned the hard way with soldered connections not that stranded wire is more flexible and durable than solid wire, its the interface connection that takes the hit and how you deal with it
PTFE (Teflon) is only semi-crystalline, with only about a third of the molecules partially aligned. That means little here. It is not crystalline in the usual sense of being jagged or sharp. PTFE has one of the lowest coefficients of friction of any material. So it’s “slippery”, allowing internal strands to slide more easily. Anyway, we’re comparing the hypothetical case of PTFE-insulated solid wire versus PTFE-insulated stranded.
Of course the greatest stresses do occur on the terminated ends in both cases. That is where fatigue and eventual breakage will occur. For the same amount of flexure, the tiny strands see less relative stress, while the stiffer solid core endures more. Don’t mistake the stiffness of solid core as “strength”. It’s actually a weakness. For the same amount of flexure, more work (“work” here in the physics sense) has to be expended into overcoming that stiffness. The result is more cold work hardening in the solid core. This results in greater brittleness and formation of stress fractures. If you run both kinds of wire under the same vibration environment for years until hard failure, the solid core would break first. You might lose a strand or two in the multi strand wire but there still might be 95% conductivity.
Take it from a retired aerospace engineer: It is common practice to use highly-stranded PTFE wire in high-vibration environments. Low/coarse stranding or solid core (of the same gauge) would not be allowed in these critical cases, because they will fatigue sooner. M16878 is the standard hookup wire. It is readily available to us hobbyists.
Ever wonder why the Golden Gate Bridge uses multi-stranded support cables?
Of course the greatest stresses do occur on the terminated ends in both cases. That is where fatigue and eventual breakage will occur. For the same amount of flexure, the tiny strands see less relative stress, while the stiffer solid core endures more. Don’t mistake the stiffness of solid core as “strength”. It’s actually a weakness. For the same amount of flexure, more work (“work” here in the physics sense) has to be expended into overcoming that stiffness. The result is more cold work hardening in the solid core. This results in greater brittleness and formation of stress fractures. If you run both kinds of wire under the same vibration environment for years until hard failure, the solid core would break first. You might lose a strand or two in the multi strand wire but there still might be 95% conductivity.
Take it from a retired aerospace engineer: It is common practice to use highly-stranded PTFE wire in high-vibration environments. Low/coarse stranding or solid core (of the same gauge) would not be allowed in these critical cases, because they will fatigue sooner. M16878 is the standard hookup wire. It is readily available to us hobbyists.
Ever wonder why the Golden Gate Bridge uses multi-stranded support cables?
An engineer I worked with at Digital told me he did the actual vibration testing between a crimped and soldered connection; crimped outlasting the soldered every time.
Yes, I think I’ve heard that too. In aerospace applications both crimped and soldered connections are used, depending on the connecter.
Soldering is just good for fixing and the vibration test shows that even there its suboptimal solution. Its just easy and cheap. Solder is a very bad conductor, thats why I always wrap and after that, then solder to fix this joint. Only soldering brings bad sound. This couldn't be auditioned with only one joint, but gear has hundreds of them and the sum is what is audible.
Btw, I know at least one reputed manufacturer who offers TFE cable as speaker cables.
Won't tell which it is, but the cable is a mixture of PVC and TFE insulator.
Btw, I know at least one reputed manufacturer who offers TFE cable as speaker cables.
Won't tell which it is, but the cable is a mixture of PVC and TFE insulator.
How much vibration is used for those tests?
I mean, this is interesting, but does it relate to audio-gear, or is it more like Saturn V?
Now you’re making me LOL. Wernher von Braun did not develop modern NASA electrical standards. There is a lot of solder in fighter jets, satellites and manned spacecraft. A lot of crimps too. Done correctly, each can be reliable:
https://nepp.nasa.gov/docuploads/06AA01BA-FC7E-4094-AE829CE371A7B05D/NASA-STD-8739.3.pdf
https://nepp.nasa.gov/docuploads/06AA01BA-FC7E-4094-AE829CE371A7B05D/NASA-STD-8739.3.pdf
DoD prohibits the use of silver plated Teflon insulated copper wire in electronics equipment. This is because Teflon will flow under pressure and silver plated copper wire is subject to the "red plague" which results in the disintegration of the wire.
Red Plague: Damaging Corrosion in Wires.
Red Plague: Damaging Corrosion in Wires.
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