Calling BS on dual coils!

[sawlight]

While it would likely only fit well in a huge box mod with an integrated atty, and be hugely expensive, and technically difficult... this could work! I'm thinking infrared thermometer hooked into a fancy VW module that could regulate voltage accordingly, keeping your coil at the "perfect temperature".

Where are our electrical engineers?

Why over complicate it, a simple thermocouple on the coil can send the information back and have it self regulate.

Why complicate it? Everything you need to know is right here:
When we’re talking about ohms and ecigarette parts what we’re really concerned with is what kind of heat the coil is generating to evaporate our eliquid.
There are effectively 2 things that determine how hot the coil element gets; battery voltage and the ohm rating of parts attached to the battery. Higher battery voltage and lower resistance both create more heat for evaporation. Heat produced by the ecigarette will impact flavor, vapor production and your overall experience. Using ohms we can fine tune the vapor production and flavor that best matches the batteries we own.
http://electronic-cigarettestarterkit.com/ecigarette-parts-ohms-explained/

Yes, no, maybe, not really, and all of the above. Different wires heat differently, different juices heat differently, different mixes of PG and VG heat differently, different wicks heat differently and so on and on. How much juice is getting fed to the wick, how much juice can the wick hold? Why is the same build, using the same wick, wire and juice in my Kayfun and Fogger so different? The Kayfun is fat dumb and happy at 8 watts, the Fogger wants 13 watts, why?
VW was supposed to fix this with it's "set it and forget it" mentality, but it really hasn't worked out like that, there are still to many variances we haven't figured out yet.

 

[Vaslovik]

Yes, I did the dual coil think on my IGO-W, and on my AGA-T2, and I can't say that I was at all impressed with the results, or return on effort and kanthal. Dual coils just drained my batteries faster, and I can't say it provided any better vape at all. It was an interesting venture as far as it went, but I really didn't find it to be worth doing. I just stick with single coils now, and the IGO-W has been sitting in the cigar box for months now. The dripping venture didn't pan out for me either. I went right back to my RSST and stayed there, on a single coil.

 

[Sirius]

Why over complicate it, a simple thermocouple on the coil can send the information back and have it self regulate.



The Kayfun is fat dumb and happy at 8 watts, the Fogger wants 13 watts, why?
VW was supposed to fix this with it's "set it and forget it" mentality, but it really hasn't worked out like that, there are still to many variances we haven't figured out yet.

Fat dumb and happy works for me. My Trident V2 non-regulated on a mechanical is the best for me I have found. No VV/VW needed. For me as I said some would disagree I'm sure.

 

[Mitey F]

Why over complicate it, a simple thermocouple on the coil can send the information back and have it self regulate.



Yes, no, maybe, not really, and all of the above. Different wires heat differently, different juices heat differently, different mixes of PG and VG heat differently, different wicks heat differently and so on and on. How much juice is getting fed to the wick, how much juice can the wick hold? Why is the same build, using the same wick, wire and juice in my Kayfun and Fogger so different? The Kayfun is fat dumb and happy at 8 watts, the Fogger wants 13 watts, why?
VW was supposed to fix this with it's "set it and forget it" mentality, but it really hasn't worked out like that, there are still to many variances we haven't figured out yet.

Thermocouple... I should have thought of that. I was thinking "unobtrusive" and thus as few things IN the atty as possible, but your're right.

You're also right about wicking. Ohms and voltage (watts/amps) are not the ONLY thing that contribute to heat. Wicking plays a HUGE part, as the wick is what keeps the coil from reaching temps above what our nic-goo vaporizes at.

 

[roadie]

A dual coil at 1 ohm each and an OVERALL resistance of 0.5 ohms will give twice the vapor of a single coil at 1 ohm. If you are comparing duals at 2 ohm EACH with an overall resistance of 1 ohm then it won't. This has been my experience with many experiments. Of course, this is assuming the coils are built properly and exactly the same, wicking the same, amount of juice the same going to each coil at the same rate, etc. Otherwise, who knows with too many variables.

 

[rurwin]

It might be possible to measure temperature by watching the change in resistance. It would seem to be easy with nichrome, but kanthal is designed to have a constant resistivity. It still might be possible if we can measure voltage and current to within 0.1%.

 

[emus]

Here's my pile of BS and watch your step because there's more.

 

[certus11]

Here's my pile of BS and watch your step because there's more.

We are obviously just wasting time/efficiency when we build duals.

Best cloud chaser I have seen run dual coils at .07 ohm. If dual offered no advantage, I'm sure the dude would have went with single to save time also.

Yep people who swear by duals most like know more than those who blablabla.

 

[Maurice Pudlo]

Here's my pile of BS and watch your step because there's more.

That's some very nice cattle dung you have there. Mind if I ask why you don't wind the multi strand wire a bit tighter?

Maurice

 

[Maurice Pudlo]

This is 4 strands of 32ga, I've used 1, 2, 3, and 4 strands per single coil, its more versatile in my opinion than 28ga.

Maurice

 

[Myk]

Its good to know you found a happy place for your device; still ohms don't do the burning that's temperature accumulation in a coil with little or no juice flow.

Its very much like boiling water in a pan, if you put a pan on a high flame the pan will eventually glow red hot. But if you continually fill the pan with water at the same rate it boils off the pan will never get overly hot.

It would be fantastic if our devices were regulated by coil temperature real time, that would eliminate burning. For now we run on indirect regulation, sort of like expecting one throttle position to maintain your cars exact speed regardless of the cars load, or if it is climbing a hill or descending the other side.

If your cars throttle is fixed, and you want a stable speed you need to adjust the road, in our case it isn't the road but juice delivery. More or less flow to the coil is what works to ensure the coil remains in the optimal temperature range.

I think the advantage of multiple coils is that they tend to be shorter, thus juice doesn't become depleted prior to reaching a still heated portion of the coil, this is especially the case where each coil is fed by its own wick, and even more so if the wick feeds both ends of the coil.

Run correctly multiple coils just produce more vapor, sure it will deplete battery charge faster, but if your wanting lots more vapor, it is going to use both more juice and more power from your battery. Given similar coil and wick design.

Different wicks and coil designs aren't exactly side to side comparisons. Certainly when all that counts is if the coil vaporizes your juice.

Maurice

My issue wasn't feed rate. My issue is ohms.
I like to cook on cast iron skillets. Thin stainless skillets burn food. A 1" thick hunk of metal takes too long to heat up.
I like the same wire and ohms in a dripper as I like in a gennie. I like the same wire and ohms x2 in a dual.
To get those x2 coils cooking took more power.

And my coils are huge

 

[sawtoothscream]

I have the trident and love it.

went from .7 single on a igo l to .5 dual on the trident. after awhile i went to .7 single on the trident and thats the ticket for me. vape production looks the same but its easier to build, doesnt kill the battery as fast.

 

[emus]

That's some very nice cattle dung you have there. Mind if I ask why you don't wind the multi strand wire a bit tighter?

Maurice

I wind 10 feet at a time and that's what I get.
Maybe I'll squeeze some tighter dung next time

 

[emus]

View attachment 315190
This is 4 strands of 32ga, I've used 1, 2, 3, and 4 strands per single coil, its more versatile in my opinion than 28ga.

Maurice

I'm fresh out of 32 but I like your style.

 

[Smithereens]

my friend, you are doing it wrong. 2.6 ohm coil won't give you much vapor and two of those wont give you much more vapor because you don't get twice the vapor in dual coils you get at most 75% more vapor.

I suggest you test you build a .5 dual coil (1 ohm each) and test it against your other device at at .5 ohm

you will be pleasantly surprised. When happens with low sub ohm is that the increase in vapor suffer from diminishing return. So there's a break point where dual coils will outperform single big a huge margin

you are basically trying to disprove lots of vapers who swear by dual coils. stop and think for a moment, are you sure that you are more knowledgeable than them?

You obviously don't know what you are doing just yet, you'll get there.

example: I have yet to see someone claim that kayfun output more vapor than aqua.

Now that's pretty condescending! Take a good look at what I was comparing and what my stated results were for the assigned parameters.

I setup two totally different RDAs with the same resistance just to see how they compared on overall performance, with the criteria being power consumption, vapor production and flavor at greater than 1 ohm resistance. Power consumption should have been the same, but there's now way that was the case. Obviously I didn't connect my ammeter and check the actual current draw, but my experience says the dual coil used up more power for a very similar return. So you must forgive the purely anecdotal evidence, next time I will construct a more rigidly defined experiment complete with test data, charts and 8x10 color glossy photographs.

And the whole "The only way to Salvation is through sub-ohming." mantra is very,very trite. I sometimes run my Trident as low as .5 of an ohm, and yes, it's a fog blaster. But that isn't my point.

I understand that critical reading skills are hard, but keep trying, you might someday get there!

 

[Smithereens]

I wind 10 feet at a time and that's what I get.
Maybe I'll squeeze some tighter dung next time

Emus,

I really hate that you're taking what I said so hard! (Really, in all seriousness.)
Apparently you guys are taking it that I'm some sort of anti-dual coil, neoconservative, Nazi freak.... which is really weird, but, whatever! That's not the case anyway. I actually have a few more dual coil and a quad coil RDA on the way (and a couple of single coil too). They each have there place. Out and about, I like the single coil at 1 to 1.3 ohm... that way I'm not carrying a couple of extra batteries or having a battery crap out at a bad time. At home, .5 dual coils... batteries be damned (but the wife does complain!).

How many of those W's are you running at more than a whole, entire ohm? Would you run them at... say 1.8 ohms? It would be a waste of time, right? Why would it be a waste of time? If you actually answered those questions then you have just followed the same thought process that lies behind my original post. I did it just to see which worked better overall.

You guys are starting to act like I just shot your dog and then flipped you a bird! You gotta read past the thread title.

Nice builds, BTW!

 

[Smithereens]

I have the trident and love it.

went from .7 single on a igo l to .5 dual on the trident. after awhile i went to .7 single on the trident and thats the ticket for me. vape production looks the same but its easier to build, doesnt kill the battery as fast.

That was going to be my next experiment. .65 of an ohm on a single and on a dual. just to compare things like longevity of the build, battery life and overall how nice or poor each build is to live with.... But I don't think I'll say anything about the results one here! I'd hate to find my cat crucified to my front door after saying that a .65 single coil build gums up and burns wicks too fast!

 

[Dampmaskin]

There are effectively 2 things that determine how hot the coil element gets; battery voltage and the ohm rating of parts attached to the battery.

Strictly speaking, heat is not the same as temperature, and I think this statement conflates these terms. If "how hot the coil element gets" is supposed to mean "how high a temperature it reaches", the statement is relevant but incorrect. If it is supposed to mean "how much thermal energy it puts out", the statement is correct but irrelevant.

For vaping purposes we are interested in getting the surface temperature right. Too high a temperature, and the juice will burn. Too low, and it will not vaporize properly. This has little or nothing to do with the size of the coil's surface.

Incidentally, this also explains why variable wattage turned out not to be the magic bullet that it was hoped to be. A good VW circuit can ensure a constant heat between different attys, but it can not ensure what matters: A constant temperature.

 

[rurwin]

For vaping purposes we are interested in getting the surface temperature right. Too high a temperature, and the juice will burn. Too low, and it will not vaporize properly. This has little or nothing to do with the size of the coil's surface.

It has everything to do with the size of the coil's surface, since the transfer of heat to the liquid depends on the contact area between them. If there is a small surface then the coil will not shed heat efficiently and it will reach a higher temperature. If the area is too large then it will transfer so much heat that it will not reach a high enough temperature quickly enough.

The final temperature that the coil attains depends solely on its surface area, since it only interacts with its environment through its surface. The final temperature is reached when the heat being transferred out is equal to the heat being generated. When dry, heat transfer is mainly by radiation, and the coil gets orange hot. When well wicked, heat transfer is mainly by conduction, and the coil stays much cooler. Both radiation and conduction are proportional to the surface area.

 

[Dampmaskin]

Yeah, everything is connected to everything, and I phrased it sloppily.