My caveat with dual coil RDAs....

[ZombieSlayer]

I've been thinking about this all day, and I think we need a new dual-coil RDA which is suited for VV/VW devices.

Although dual-coil devices are absolutely awesome and provide tons of vapor and flavor, they often times come out with very low ohms (0.8 or so it seems is the norm). The problem with that is that a lot of VV/VW devices don't like to see anything that low. My VAMO v2, for example, won't let me fire anything under 1.2 ohms.

Then it hit me; The reason they come out with such low resistance is because current dual-coil RDAs are using two loads (coils) wired in PARALLEL! What if someone were to work on a new dual-coil RDA where the coils are, instead, wired in SERIES (sum of the resistances of both coils)? This could make it possible to create a dual-coil build that won't piss off a VV/VW and allow users of these devices to get in on the dual-coil fun without any fuss about it.

 

[notawoman]

You can do dual coils in series but I believe it takes 4 times the voltage to get the same vape as a dual coil in parallel.

 

[E_DeCastro]

if you have two coils (resistors) in series why not just make one coil.

 

[ZombieSlayer]

Well, from what I can understand, the reason for having 2 coils is so that you get an optimal amount of heat across 2 coils to produce tons of vapor and flavor instead of running one coil really hot and possibly burning everything you put in it (and probably getting a nasty throat hit to boot). What I'm thinking is one could use a lower gauge wire for both coils to lower the ohms per wind, thus getting a useable number of winds per coil without the 2 coils adding up to high ohms. This would allow one to enjoy the benefits of having 2 coils without worrying about sub-ohms keeping you from using it on your favorite VV/VW mod.

 

[Mad Scientist]

I've been thinking about this all day, and I think we need a new dual-coil RDA which is suited for VV/VW devices.

Although dual-coil devices are absolutely awesome and provide tons of vapor and flavor, they often times come out with very low ohms (0.8 or so it seems is the norm). The problem with that is that a lot of VV/VW devices don't like to see anything that low. My VAMO v2, for example, won't let me fire anything under 1.2 ohms.

Then it hit me; The reason they come out with such low resistance is because current dual-coil RDAs are using two loads (coils) wired in PARALLEL! What if someone were to work on a new dual-coil RDA where the coils are, instead, wired in SERIES (sum of the resistances of both coils)? This could make it possible to create a dual-coil build that won't piss off a VV/VW and allow users of these devices to get in on the dual-coil fun without any fuss about it.

The common limit on a regulated mod these days is 15 watts. Assuming each coil of a dual coil setup is of equal resistance, that's 7.5 watts a piece. It is possible to make two sets of high performance coil builds that will run very well at 7.5 watts each, but is pretty much pointless instead of just running a decent single coil RBA at 15 watts.

The idea is to make two sets of high wattage atomizer builds in the dual coil RBA -- why, I don't get (i've found I don't actually like outrageous plumes) but it is a cloud factory.

 

[ZombieSlayer]

The common limit on a regulated mod these days is 15 watts. Assuming each coil of a dual coil setup is of equal resistance, that's 7.5 watts a piece. It is possible to make two sets of high performance coil builds that will run very well at 7.5 watts each, but is pretty much pointless instead of just running a decent single coil RBA at 15 watts.

The idea is to make two sets of high wattage atomizer builds in the dual coil RBA -- why, I don't get (i've found I don't actually like outrageous plumes) but it is a cloud factory.

So in other words, a dual-coil RDA for VV/VW is impossible?

 

[LeoRex]

Just wrap high resistance coils. I can wrap microcoils with 32g that read well into the 3s. Putting a dual coil build around 1.6-1.8 ohms.

 

[Mad Scientist]

So in other words, a dual-coil RDA for VV/VW is impossible?

No, not at all. I wrap lots of coils that perform very well down to 6 watts, and it is very easy to go even lower, but the vape experience is vastly different from what you start getting around 10 or 11 watts and up (and up ...). What I'm getting at is a pair of well built 7.5 watt coils, that are designed to perform well at such relatively low power, won't really outdo by a whole lot a single coil at 15, designed and built to perform well at 15. A pair of coils each drawing 15 watts (over 8 amps total at typical voltage) is a whole different animal.

 

[ZombieSlayer]

No, not at all. I wrap lots of coils that perform very well down to 6 watts, and it is very easy to go even lower, but the vape experience is vastly different from what you start getting around 10 or 11 watts and up (and up ...). What I'm getting at is a pair of well built 7.5 watt coils, that are designed to perform well at such relatively low power, won't really outdo by a whole lot a single coil at 15, designed and built to perform well at 15. A pair of coils each drawing 15 watts (over 8 amps total at typical voltage) is a whole different animal.

I think I see what you're getting at. In that case, do you think boring out the airhole and possibly adding another one on a single coil will get me the clouds I'm looking for?

 

[zazz]

i've seen it done, take a 9 wrap coil, bend it midway and rotate one half, straighten out the middle wrap and you'll have two smaller coils side by side with a straight piece in the middle. It may increase your surface area and possibly heat up quicker but you're still getting the same current/wattage as just one bigger coil of the same resistance

 

[Dougiestyle]

I typically have a ~2ohm coil going around ~9w all day on my VW bottomfeeder. It produces satisfying vapor and flavor. I tried a dual coil on the same RDA and it was a significantly cooler vapor. I plugged one hole and set it up with the single coil from then on.

 

[Mad Scientist]

I think I see what you're getting at. In that case, do you think boring out the airhole and possibly adding another one on a single coil will get me the clouds I'm looking for?

Try it. Not much to lose. If you are getting good at making an atomizer that works really well at around 7 watts, two with dual airflow will be much better. If it doesn't perform up to your expectations, get an inexpensive mech and a couple of high discharge rate batteries and keep upping the power input to the coils (by lowering resistance of the build).

I've found for myself though that I'm very satisfied with around 7 watts with one of my 7 watt builds. I've learned how to make coil and wick using a variety of wicking materials that will perform all the way to using a relatively huge amount of power (50 watts and up -- not from a battery of course) and when I build for more power, it's just too much vape for me (never thought I would say that but there is a point where it is too much). Everyone has a different "too much."

At a certain point, an atomizer will boil and vaporize enough juice that you might as well just drink it lol.

 

[WattWick]

A dual coil in series is essentially a long single coil. If you really want to, you can cut a length of Kanthal in two and twist it back together again.

 

[ZombieSlayer]

A dual coil in series is essentially a long single coil. If you really want to, you can cut a length of Kanthal in two and twist it back together again.

I was thinking that, but then I thought about how to keep the coil from shorting against the bottom of the juice well. It could work if, say, you had the positive and negative posts more towards the middle, and one that is insulated from the atty towards the edge that would be used to join the two coils together. In my mind, that would A) Keep the coils off of the atty floor and keep them from shorting against it, and B) allow them to be placed in a "V" formation inside the atty with two air holes in the atty shell positioned to allow airflow to both simultaneously. Crazy idea, I know, but I think that would ensure a more stable build if you wanted to essentially do a long coil of sorts.