Contact Micro Coils Vs Spaced Coils

[etherealink]

When higher pressures force open large gaps you'll cease to see smaller ones. Remember a tensioned micro will resume it's orientation after the firing. And if done right you've oxidized those turn surfaces as uniformly as practicable at the outset ensuring a continued reliable resistance value. So it's all good. Best of both worlds. Tensioned micros are not just close spaced coils. That ignores function. The fact that the physics principle of strain locked the geometry of the coil. It does not tend to blast apart from the violence of vaporization as readily as a formed and torched coil.

What I try to encourage is the application of steady tension. It takes a little practice but its not difficult for the average person to do. It's actually harder to force it than to just go with the flow. It's deviations in the wind that cause anomalies in oxidizing to a good insulation barrier and the resulting thermal lack of uniformity (hot segments). But it just takes seconds to correct. If delicate compression adjustments dont quickly cure it just wind a good one. Also to be considered is that the wire itself has aberrations of its surface and diameter. That can be an obstacle to getting a good pulsing result. Whether a contact or tensioned symmetrical spaced wind surface anomalies can require more pulsing. Slow and easy and if progress stalls again, wind an extra either before or after. Our time is precious. Just make the best of it and your vape will follow.

Good luck E.

I totally agree, when done right, a gentle tease with a needle nose (insulated handles for heat...) a time or two and a pulse and all is right for several weeks.

Fire and hold... bad things happen.

 

[etherealink]

Mac sorry but i am having trouble understanding fully. So what you mean is that a not so perfect tensioned coil is better than a perfectly tensioned coil? But that contradicts with saying that we need to tension it the most physically possible.

Aal, I could be wrong but I have a thought on what Mac was saying from observations with large gauge wire.

The wire, when made and wrapped st the factory, has a lay to it that is similar to the lay of a rope. On the spool it is wrapped under tension and is very hard to see in smaller gauges, but a bit more evident in larger (24awg and above) in that it is twisted slightly and does not lay "naturally" when simply unwound from the spool.

The tension winding I have been playing with is to try to let the wire lay naturally as is would if you simply dropped it, like a slinky would uncoil. The wire may twist in your hands, but lay "true" on the mandrel and thus in the coil as far as structure of the wire geometry is concerned. Nothing is twisted, if 12 o'clock starts at 12 o'clock and there are an even number of wraps, it ends at 12 o'clock.

Just my take on things, still have yet to try " straightening" kanthal with a drill though...

 

[Aal_]

Aal, I could be wrong but I have a thought on what Mac was saying from observations with large gauge wire.

The wire, when made and wrapped st the factory, has a lay to it that is similar to the lay of a rope. On the spool it is wrapped under tension and is very hard to see in smaller gauges, but a bit more evident in larger (24awg and above) in that it is twisted slightly and does not lay "naturally" when simply unwound from the spool.

The tension winding I have been playing with is to try to let the wire lay naturally as is would if you simply dropped it, like a slinky would uncoil. The wire may twist in your hands, but lay "true" on the mandrel and thus in the coil as far as structure of the wire geometry is concerned. Nothing is twisted, if 12 o'clock starts at 12 o'clock and there are an even number of wraps, it ends at 12 o'clock.

Just my take on things, still have yet to try " straightening" kanthal with a drill though...

I use a pin vise while wrapping. How does my wrapping should be to ensure it is laying naturally? I cannot see the procedure in my head.

 

[etherealink]

I use a pin vise while wrapping. How does my wrapping should be to ensure it is laying naturally? I cannot see the procedure in my head.

I've done a great deal of rope work so it just kind of lays in my head but let me see if I can explain a bit better.

I normally run 20 awg ni80 and it has a definite "lay" to it, or way that the wire wants to coil itself if left alone.

**BTW, a back and forth yourself and my wife had about speaking Swahili just popped to mind... how would one translate "may you lead an interesting life" in Swahili?**

Sorry, too much vape, too little sleep lol.

Anyway, a well twisted or "laid" rope will always turn back on itself as it relaxes into the twisting process of being laid into multiple strands that work as a single unit. Even yarn left to unravel does the same.

The wire, under gentle to moderate tension will twist slightly in hand to show the direction it was manufactured, fighting this while wrapping means nothing in performance but a great deal in longevity.

If you allow the wire to lay as it wants and apply tension to enforce it, the coil simply sinks deeper into what it knows since it was created.

(If you have a moment, Google a 4-strand Sennit plait/braid, and think of the strands pulling from each end gently, as if mounted in an rda. Then, see them relax into a final position as they swell when pulsed and gently teased with tweezers)

If I recall correctly, with a pin vise you wrap similar to a precision screwdriver (ala in-hand, nothing holding tension on the leading end of the wire but your hand); notice if you see a small rotation in the wire as it follows its natural "extruded" path from the factory. If not, the wire may seem to fight the coiling process and spring out or shape.

If coiled under tension and with the lay of the wire, even a handwrapped coil can out-last and outperform one made on a fancy jig as the wire is tightening its shape onto the next wrap and so on...

I you would like some 20ga to see the idea more easily, I would be happy To send some. Sadly this is a matter of feel, and not something I can put in pictures.

 

[Moxienator]

**BTW, a back and forth yourself and my wife had about speaking Swahili just popped to mind... how would one translate "may you lead an interesting life" in Swahili?**

Cursing is not allowed on ECF.

sent via Droid Mini

 

[MacTechVpr]

I've done a great deal of rope work so it just kind of lays in my head but let me see if I can explain a bit better.

I normally run 20 awg ni80 and it has a definite "lay" to it, or way that the wire wants to coil itself if left alone.

**BTW, a back and forth yourself and my wife had about speaking Swahili just popped to mind... how would one translate "may you lead an interesting life" in Swahili?**

Sorry, too much vape, too little sleep lol.

Anyway, a well twisted or "laid" rope will always turn back on itself as it relaxes into the twisting process of being laid into multiple strands that work as a single unit. Even yarn left to unravel does the same.

The wire, under gentle to moderate tension will twist slightly in hand to show the direction it was manufactured, fighting this while wrapping means nothing in performance but a great deal in longevity.

If you allow the wire to lay as it wants and apply tension to enforce it, the coil simply sinks deeper into what it knows since it was created.

(If you have a moment, Google a 4-strand Sennit plait/braid, and think of the strands pulling from each end gently, as if mounted in an RDA. Then, see them relax into a final position as they swell when pulsed and gently teased with tweezers)

If I recall correctly, with a pin vise you wrap similar to a precision screwdriver (ala in-hand, nothing holding tension on the leading end of the wire but your hand); notice if you see a small rotation in the wire as it follows its natural "extruded" path from the factory. If not, the wire may seem to fight the coiling process and spring out or shape.

If coiled under tension and with the lay of the wire, even a handwrapped coil can out-last and outperform one made on a fancy jig as the wire is tightening its shape onto the next wrap and so on...

I you would like some 20ga to see the idea more easily, I would be happy To send some. Sadly this is a matter of feel, and not something I can put in pictures.

Now your thinking like me E. Test every proposition with the contrarian argument. The truth may lie somewhere in the middle.

I gather you wish to evaluate the performance of the wire with all (or most) of the tension removed whether loosely symmetrically spaced or tensioned into contact. Have done both my friend. I won't belabor you with my conclusions to override your curiosity. I was the kid who had to take apart every toy I got. It's all good.



Good luck.

 

[Aal_]

Sorry guys. I feel I'm really stupid. Or my English is fading. I still don't get it . Are you saying it is better to counter the natural tension it had with the spool, or better to go with it? Is our intention to make the wire forget how it was tensioned before or the contrary make use of the previous tension????

 

[MacTechVpr]

Mac sorry but i am having trouble understanding fully. So what you mean is that a not so perfect tensioned coil is better than a perfectly tensioned coil? But that contradicts with saying that we need to tension it the most physically possible.

There is no perfectly tensioned coil. Only adhesion as I refer to the metal's closest state. I don't see a point of advantage beyond adhesion. And I'm reporting that you increase resistance as you thin wire and add more. No doubt some will point out that this is minimal. However, it's routinely noted here on ECF that leads and element itself get disproportionately hot with very tight winds. I agree. And it's observable on videos of such winds.

I think that's why some are experiencing problems. A hot coil, a hot vape or not necessarily a good thing. The assumption that more is better. Too much of good thing isn't always. It's definitely so with strain production. We can overly strain the material.

I've never suggested that we tension as tight as possible. If I did last Fall as I was introducing the principles of tension using forceps or needle-nose to apply strain, it was because some were not using enough force to reach adhesion.

My own experiments when Kanger grommet composition changed to softer silicone this Spring and it seemed that adding more tension to the leads in clearos would limit their shifting with torquing of the 510 connection. Almost immediately these techniques resulted in extremely uniform builds. So much so that the leads as well as the coil shared the same color temperature. In some instances almost white hot (on ceramic wick). Wonderful I thought. Even more heat output. That is too hot for Kanthal and wick media and accordingly it quickly sours the juice and the build.

What we want is a cool, uniform distributed radiation. Closer to juices' evaporation point rather than further away.

That's why I teach adhesion to newcomers. Human brain's a beautiful thing Aal in that we can quite easily detect it.

Good luck.

 

[Aal_]

It seems my brain is not that beautiful after all. I don't know when to stop tensioning. I always go with the most tension however once I place it in the atty and depending on the atty this tension is either more tensioned less tensioned or stay the same. I need to know loud and clear how much tensioning should I do for the coil and how much tensioning for the leads.

 

[MacTechVpr]

As far as gunking coils, this is what I've found;

The "gunk" is juice reduction and carmalized sugars produced when the juice boils without completely vaporizing. To see this, you can heat a small amount of juice in a metal spoon until it boils, and eventually you will be left with that familiar brown gunky residue. FYI, if you do this in proximity to refilling needles and balls of cotton, people will talk, just saying.

Gunk production is higher with tightly spaced coils, and smaller diameter wraps, because the coil surface to wick volume ratio is higher. This means there is less "cool" juice available to soak up the leftover heat once you shut off current flow. Ergo, it takes longer for the coil surface to fully cool, and the more time the juice spends in the "gunk zone", above boiling but below vaporizing temperature. More time in the gunk zone, more gunk production, more gunk ends up sitting on the coil.

Creating space between the wraps, and increasing the wrap diameter, gives more "cool" juice volume to coil area, reducing the time to cool. However this makes the coil less efficient when firing because the coils cannot share heat as effectivley, diminishing the surface area heated to the vaporizing point.

Using stainless mesh as a wick helps reduce gunk, since mesh is a much better thermal conductor than cotton/rayon/silica. This gets the juice tempurature down under the boiling point quicker.

A way to reduce gunk without changing the coil build or wick material is to continue drawing for a few seconds after shutting off power. This will let air cool the coils quicker. For RDAs at least, it might have unintended consequences with RTAs/clearos/carts.

Ideally, we would have a wet flavor wick, attached to an armature, and as we killed power to the coils, it would lower the wet, cool wick onto the exterier of the coils, cooling them faster and eliminating gunk. However in practice, this would probably be overkill vs. regular rewicking and dry burns.

Again, this is just my experience, and my SWAG at what's going on. The way to test this theory would be to build a coil of sufficient size and thermal mass that it's heating and cooling cycle could be observed with a thermal imaging camera. Something along the lines of 1/4" kanthal wrapped around a quarter pound of cotton and powered by a dozen car batteries should do the trick...in other words where cloud chasers will be in a year or two .

Thoughts?

A formidable theory sign. But I don't think we need to go that far for a real life test.

I submit this picture of a design that's the epitome of a gunk zone. It's by far the cleanest producing build I've ever done. And I think to those familiar with fluid and thermal dynamics the color temperature and it's uniformity are convincing evidence of my observation. I have one now running since August. Plenty of witnesses at a well known vendor's building session, pictures taken there and posted here on ECF.

According to your proposition it should be an utter failure. In practice it's efficiency is related to its apparent and functional symmetry.

A hand-wound eccentric coil is the least effective means to achieve that end consistently, repeatably.

The heat that is just at the right temperature for vaporization applied uniformly over a given area of exposure is what presents the best opportunity for complete vaporization. Concentrate the area as in the above experiment and you get more complete processing of liquid product.

The presentation of cool zones that fall short of vaporization temperature produce gunk. They can happen even in an efficient design. When? When the wind itself is erratic.

I'll put this another way …a coil whether conventional or contact will produce gunk if underpowered (or over-wicked).

The purpose of my adaptation of strain to perfect microcoil generation was exactly to avoid those variations in surface temperatures that might produce the conditions of excess (waste energy) and the resulting inadequate vaporization in other cooler segments of a coil.

It is under-heating (I agree with you) from inefficient circuits that is the impediment to a great repeatable vape.

Good luck sign.

 

[MacTechVpr]

It seems my brain is not that beautiful after all. I don't know when to stop tensioning. I always go with the most tension however once I place it in the atty and depending on the atty this tension is either more tensioned less tensioned or stay the same. I need to know loud and clear how much tensioning should I do for the coil and how much tensioning for the leads.

No it is all. And it's all still there. Now worries. I know I feel the same sometimes.

Look, you use as much as you need to get the wire "sticky". It's probably going to take some adjustment now as you been going for tightest.You just ease up a little bit. You'll know if you dropped the tension too much…the wire will separate.

Just add a little more. Most important keep the tension steady.

You're already making these things successfully so that's half the battle.

Good luck Aal.

 

[Aal_]

No it is all. And it's all still there. Now worries. I know I feel the same sometimes.

Look, you use as much as you need to get the wire "sticky". It's probably going to take some adjustment now as you been going for tightest.You just ease up a little bit. You'll know if you dropped the tension too much…the wire will separate.

Just add a little more. Most important keep the tension steady.

You're already making these things successfully so that's half the battle.

Good luck Aal.

Thanks Mac. One more question that went unanswered. Is it better to wrap against the turn of the wire in the spool or with it?

 

[MacTechVpr]

Thanks for the comeback aal. I'm right handed, I turn clockwise (facing the point of the bit). There's no correct way. Either way is good. I use opposing winds to do top screw mounts for example (center post screw for pos, post holes for neg leads). Or a high-low arrangement of the leads. Talking about the bit rotation.

If you mean the direction of the wire as it's sitting on the spool. I don't think it matters. The tension it bears is minor and easily overcome by the tension of hand winding. After that it's what you did that the wire remembers.

Good luck to ya aal.

 

[Moxienator]

A lot of food for thought and experimentation, Mac.

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[Signmaker]

I submit this picture of a design that's the epitome of a gunk zone. It's by far the cleanest producing build I've ever done. And I think to those familiar with fluid and thermal dynamics the color temperature and it's uniformity are convincing evidence of my observation. I have one now running since August. Plenty of witnesses at a well known vendor's building session, pictures taken there and posted here on ECF.

According to your proposition it should be an utter failure. In practice it's efficiency is related to its apparent and functional symmetry.

Can you set me up with a link, or send me the info on that build via PM? I've had something very similar to that concept swimming in my head for a bit now.

Actually Mac, I'd submit that your coil proves my theory. I'm just going off what I see in that one pic, but it looks like you're running thinner wire (28ga?) on a larger diameter (3/16"?). So what you have is a heating element with low thermal mass, in contact with a large volume of wick, enabling a faster transition from "cool" to "vaporization", and spending less time in the "gunk zone".

I beleive you are correct in your thoughts about coil tension/adhesion helping the efficiency as it relates to gunk. If all wraps of a coil transition up to operating temperature evenly, without hot/cold spots, it gives less oppurtunity for gunk formation.

It us under-heating (I agree with you) from inefficient circuits that is the impediment to a great repeatable vape.

Well since we have to spend some amount of time under heating our coils before they reach vaporization temperature, would you agree the second half to the efficiency equasion would be a programmable power source that allows voltage to be applied on a curve? If we take a coil with as much efficiency as can be built into it, and apply high voltage in the initial milliseconds of a burn, we can bring it to optimum vaporizing temperature faster. Once in the "vapor zone", voltage can be backed off to maintain am optimum vape.

I know the new "temperature control" chipsets do something like this now, but it's still not an exact level of control, since it's only modulating power based off coil resistance as it heats. I think the next level we have to hit are user-programmable power sources that can have custom-tailored power curves, similar to air/fuel patterning in modern automobiles. IMO, that's when efficient/uniform "sticky" coils are going to shine.

 

[MacTechVpr]

...Actually Mac, I'd submit that your coil proves my theory. I'm just going off what I see in that one pic, but it looks like you're running thinner wire (28ga?) on a larger diameter (3/16"?). So what you have is a heating element with low thermal mass, in contact with a large volume of wick, enabling a faster transition from "cool" to "vaporization", and spending less time in the "gunk zone"…

I'm not ready to refute or confirm your theory. I've read a lot off on on about juice cool down. I would submit that the time increments involved here are so minute that they're a relatively insignificant factor compared to the multi-second impact of wind inefficiency.

I'm of the view that given the same wire length, wick surface area, power and juice characteristics there must be the same amount of gunk (unvaporized solids) if equally presented to the wire surface (proximately, or in the gunk zone if you will). Then it follows that it goes downhill from there if build efficiency reduces by whatever form, e.g. inadequate power, surplus supply of product, inadequate surface contact (hot turns) and yes, spreading of power by spacing so as to attenuate it's concentration.

Don't have much time tonite to go much beyond the gunk LOL. It is an intriguing subject to me as I love tobacco's. So I feel for you all in my plight. If I had found such a concrete and certain solution I would be right at the front of the line waving that banner. Unfortunately I can't consistently reproduce the superlatives many rave about. And to the bulk of us that's what matters.

And microcoils are no exception. There is no perfect solution for some of the densest most complex liquids we vape. Square peg, round hole situation I feel. There are no categorical absolutes except efficiency.

Asking around for anecdotal affirmations don't cut it. We must be able to get it. Gimme a wind you can build consistently inside of 6-8 minutes that works every time efficiently or reliably in something as finicky as a Protank. Or a complex build such as the following inside of 15 or so (with the right method and tools) and you've got an advocate and a sponsor.

But before KGD and without Nextel I couldn't get wick density right often enough to make that average. And I don't think most could with more than or two juice and device types. I'm just an average builder you see.



The Twisted Lead Center Post build I've talked about and pictured example above is a 16-turn 28AWG D/C TLCP, 8/7, #44WG 2.18mm i.d., t.m.c. = 0.7Ω. I'd say small and efficient with KGD. Better still in terms of of flow with ceramic fiber. And it's got a heck of a lot of wick for [TRUE] a seriously short time in the gunk zone…exactly where I want it, at just the right even temperature.

And whether I take the continuous 2 sec chain hit or the 8-10 cloud lung pull on it I've gotten a dense cloud, what many call (emphatically) COLD, cascading to the floor…I know I've seen effective, comprehensive and downright righteous transition of that juice.

If that proves your theory sign, then we're both on the right track buddy and more power to us.

Vape it good!

Good luck.

 

[MacTechVpr]

A lot of food for thought and experimentation, Mac.

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Prove all things Moxie…hold fast that which is good.

Good luck.

 

[Ian444]

I find the coils with slight spacing to greatly increase run time with gunky NET's. Also these coils with small even spaces seem to give a smooth consistent vape, smoother than contact coils. It has been mentioned that contact coils are more efficient, and in an earlier post in this thread I mentioned something to the effect of spaced coils being less efficient and requiring slight changes to match the contact coil, but the reality has turned out to be that my batteries are lasting at least as long as they were before, and I am getting a better vape experience. Another observation that surprised me was when I built my first intentionally-spaced coil, and I fired it (juiced up) with no cap on the RDA. The vapor dispersion is completely different to a contact coil.

I'm pretty well done with contact coils. No amount of theory or speculation will change that for now, its just my opinion from my own observations. That doesn't mean I can't learn anything from the contact coil proponents, in fact everything I know about coil winding is from them, and I thank them very much for that knowledge, especially Super_X, and I appreciate it. I guess that leads to the question, how far apart are they

 

[Aal_]

I find the coils with slight spacing to greatly increase run time with gunky NET's. Also these coils with small even spaces seem to give a smooth consistent vape, smoother than contact coils. It has been mentioned that contact coils are more efficient, and in an earlier post in this thread I mentioned something to the effect of spaced coils being less efficient and requiring slight changes to match the contact coil, but the reality has turned out to be that my batteries are lasting at least as long as they were before, and I am getting a better vape experience. Another observation that surprised me was when I built my first intentionally-spaced coil, and I fired it (juiced up) with no cap on the RDA. The vapor dispersion is completely different to a contact coil.

I'm pretty well done with contact coils. No amount of theory or speculation will change that for now, its just my opinion from my own observations. That doesn't mean I can't learn anything from the contact coil proponents, in fact everything I know about coil winding is from them, and I thank them very much for that knowledge, especially Super_X, and I appreciate it. I guess that leads to the question, how far apart are they

Well said, however what me and others are trying is achieving the same equally distributed heat accross the coil as the spaced coil. And i think mac has achieved that in his positive twisted tensioned mc. Once we achieve that I think we can solve the gunking issue.

Regarding your battery, it doesn't mean that they are same efficiency, because a spaced coil might be losing heat outside the vaporization context.

 

[The.Drifter]

Built this on 10/31 and the coils are still going strong, will post pics tomorrow after a full week of running this build to compare the wick/coils.

-----------------------------------------

Dual 26G spaced coils over 3mm screw came out to 0.48 ohms. On a fresh battery 4.2 Volts = 8.75 Amps at 36.75 Watts

For my spaced coils I like to use a screw to keep everything even:

Shot of the Duals after wrapping:

Side shot of a coil:

I use the screws to help mount the coils:

Shot of the mounted coils from the top:

Mounted coil shot from the side:

Couple shots of test firing

Medium glow:

more power to it:

I use Rayon for the wicking, shot of it pulled thru and trimmed to be fuzzy:

Wick juiced and tucked:

Wick chambered:

Final build shot: