RDA building

[Wake'n'Vape]

After getting sick of how unreliable the factory coils are for my subohm tanks, I decided to take the plunge and picked up my first RDA, a velocity clone and loving it so far. I find it produces a much more satisfying vape and also cost me around half the price of a subohm tank with a huge supply of wire and cotton included!

I messed around with a few simple dual coil builds, eventually settling for some that came in at 0.4ohms, which seems to be a solid compromise for me between clouds and flavour. 6 wraps of 26g kanthal on a 3mm bit.

What are the advantages of all these different coil builds? Simply using twisted wire for example.
Is there a fairly simple build anyone can recommend looking into to get even more out of this RDA?
What difference does the diameter of your coil make? i.e if you are using a 2mm as oppose to 3mm, it's going to affect the number of wraps but you will still have the same length of wire.

Thanks

 

[suprtrkr]

Those are good questions. The advantages of using wild coil builds is they greatly increase the surface area of the coil, and the surface is where the vapor comes from. The disadvantage is they also increase the mass of the coil and thus require more time to heat up, or more power to heat faster, than a slick wire coil of the same value. The advantages of using different coil mandrels is it allows you to tailor the size of the finished coil for various purposes while maintaining the same resistance. If you are using a coil calculator like Steam Engine, off in the right side you'll see the actual calculated value of the coil itself. I usually use duals, so I am looking for a calculated value exactly double the resistance I am looking for. If I see, for example, a 5 wrap on 3mm will total .92 ohms, I'll be a little under if I am shooting for a .5 ohm total. But by adjusting the mandrel, I might find a 6 wrap on a 2.5mm will total 1.02 ohms, and I'll be closer to my final desired resistance. Another key point is the space you have to work with. In some drippers, a long skinny coil fits the deck better. In others, a short, fat one might line up easier. Yet another point is, the larger the diameter, the more wick it holds. Low builds and thick juices and high watts benefit from more wick because more juice is available immediately adjacent to the coil. Finally, some tanks want more wick than others. A 2mm coil holds plenty of wick for a Kayfun. But my Indulgence MT can be a bit starved for wick-- absolutely huge juice channels-- with a 3.5mm coil; so much so I am considering buying a 4mm drill bit for it alone

 

[NightShadow]

After getting sick of how unreliable the factory coils are for my subohm tanks, I decided to take the plunge and picked up my first RDA, a velocity clone and loving it so far. I find it produces a much more satisfying vape and also cost me around half the price of a subohm tank with a huge supply of wire and cotton included!

I messed around with a few simple dual coil builds, eventually settling for some that came in at 0.4ohms, which seems to be a solid compromise for me between clouds and flavour. 6 wraps of 26g kanthal on a 3mm bit.

What are the advantages of all these different coil builds? Simply using twisted wire for example.
Is there a fairly simple build anyone can recommend looking into to get even more out of this RDA?
What difference does the diameter of your coil make? i.e if you are using a 2mm as oppose to 3mm, it's going to affect the number of wraps but you will still have the same length of wire.

Thanks

Let me try to help define part of your question here.

Please define / expound on what you mean by "get even more out of this RDA"

More flavor?
More/bigger clouds?
Better battery life?
Better/less juice consumption?
Look good in pictures?

The advantage (or disadvantage depending on YOUR preferences) of different builds is they provide some but not all of the above.

It is all about balance, you can go with a goal of maxing one thing, and find a few others at some level are included, but you cannot have all of them at the same time. Luckily we can build more than 1 coil, and use different ones for different things, clouds, taste, happy medium, etc.

The diameter of the coil as a standalone fact means next to nothing imho. Everything is an ingredient in the coil recipie, wire type, resistance, length, etc.

The diameter imho is more a function of 2 things, it either fits in the base or it does not. And what is the goal of the build and how does the size of the coil affect the recipe. One reason to use a smaller diameter coil would be if a step to reaching a goal required more airflow and less obstruction was the desired way to reaching it.

It is also possible with a given target goal with the gauge you happen to have available, it will only fit from a length perspective at larger diameter, ie same total length of overall wire, larger diameter = shorter coil vs a smaller diameter coil might be so long it would not fit inside the base. One could simply change the gauge of wire used for same effect if available.

While all that can be complicated, the steam engine makes calculating things much simpler: Coil wrapping | Steam Engine | free vaping calculators

The twisted wire could server 2 different goals, more surface area in order to have a larger area for juice to burn in order to provide bigger clouds. The non availability of a different gauge of lower resistance wire, double the wire, half the resistance.

 

[Wake'n'Vape]

What I mean by 'get even more out of this RDA' would be a balance of cloud and flavour. The setup i'm currently using works great imo, but since i'm just getting into the world of coil building I haven't got much to compare it to, and since there is a magnitude of different coil builds out there i'm wondering if there is another build that would make it even better. I have no intention of doing any super low builds and plan to stay between .4-.6 ohms for now.

 

[NightShadow]

A quick / easy suggestion would be to build a twisted coil and try it, providing your end result is near the same ohm range you use now, the extra surface area should allow for a bigger cloud, you will need to be your own judge on the flavor however. Clouds are objective, taste is subjective

This should give you a better idea what direction you would want to go from there.

 

[suprtrkr]

What I mean by 'get even more out of this RDA' would be a balance of cloud and flavour. The setup i'm currently using works great imo, but since i'm just getting into the world of coil building I haven't got much to compare it to, and since there is a magnitude of different coil builds out there i'm wondering if there is another build that would make it even better. I have no intention of doing any super low builds and plan to stay between .4-.6 ohms for now.

You could try a twist or make-- it's a PITA-- or buy some clapton wire. I like them. I usually use twists myself. They're a lot easier to do than Claptons. Plus the wire's stiffer, so it's easier to rewick several times before it breaks once you get a good build.

 

[Wake'n'Vape]

Just put a twisted build in it, was aiming for 0.4 but ended up a little over .3, yet to test it out properly as I just ran out of 3mg juice. Looking at the ohms law calculator its saying this build at 60w is drawing 14amps, i'm using a pair of LG HG2's in my iStick rated 20A. Is this load spread evenly over the 2 batterys, so 7amps each or does it not quite work like that?

 

[NightShadow]

Just put a twisted build in it, was aiming for 0.4 but ended up a little over .3, yet to test it out properly as I just ran out of 3mg juice. Looking at the ohms law calculator its saying this build at 60w is drawing 14amps, i'm using a pair of LG HG2's in my iStick rated 20A. Is this load spread evenly over the 2 batterys, so 7amps each or does it not quite work like that?

Not the battery math wizard so can't say.

I just wanted to ask what you thought of the twisted build compared to the single you had, how does it VAPE!

 

[Matty316]

Just put a twisted build in it, was aiming for 0.4 but ended up a little over .3, yet to test it out properly as I just ran out of 3mg juice. Looking at the ohms law calculator its saying this build at 60w is drawing 14amps, i'm using a pair of LG HG2's in my iStick rated 20A. Is this load spread evenly over the 2 batterys, so 7amps each or does it not quite work like that?

Depends on the type of mod you are using is it a mech or regulated? Are the batteries in a parallel or series cofiguration?

The way we calculate amp draw is different for mechs and regulated mods and the way they are drawen is different with series and parallel configurations.

 

[suprtrkr]

Just put a twisted build in it, was aiming for 0.4 but ended up a little over .3, yet to test it out properly as I just ran out of 3mg juice. Looking at the ohms law calculator its saying this build at 60w is drawing 14amps, i'm using a pair of LG HG2's in my iStick rated 20A. Is this load spread evenly over the 2 batterys, so 7amps each or does it not quite work like that?

doesn't work like that. Your iStick is a series regulated mod. You're putting 14 amps on both batteries. You would half the loading if it were a parallel mod. You should still be safe there, but if you want to go much higher in wattage, I'd throw a pair of Sony VTC 4s in the machine.

 

[Matty316]

doesn't work like that. Your iStick is a series regulated mod. You're putting 14 amps on both batteries. You would half the loading if it were a parallel mod. You should still be safe there, but if you want to go much higher in wattage, I'd throw a pair of Sony VTC 4s in the machine.

Actually at 60 watts at nominal voltage which for the hg2 is 3.7x2 = 7.4v (because of the series connection).
The math would be 60 ÷ 7.4 = 8.108 amps then add about 10% to that (I'm guessing the Istick is around 90% efficient) and you're looking at around 9 amps at 7.4v

If the mod cuts off at around 6.4v you're looking at a little under 10.5 amps @ 60w.

This is only in a regulated mod. In an unregulated mod you use I = V ÷ R

 

[suprtrkr]

Actually at 60 watts at nominal voltage which for the hg2 is 3.7x2 = 7.4v (because of the series connection).
The math would be 60 ÷ 7.4 = 8.108 amps then add about 10% to that (I'm guessing the Istick is around 90% efficient) and you're looking at around 9 amps at 7.4v

If the mod cuts off at around 6.4v you're looking at a little under 10.5 amps @ 60w.

true and thank you. I didn't do the math; just used OP's figure because I thought he'd understand better. But you are right, 9ish amps at full charge, depending on efficiency on the board, is the technically correct answer.

 

[Bad Ninja]

I get more flavor and more vapor from standard builds with kanthal, than any of those artsy builds.

Twisted, Clapton, fused flat wire builds are pretty, but you can get just as much flavor and vapor from a standard wire coil if it's built properly.


It's really more about airflow and wicking than the coil build itself.


Build your coils close to the air holes.

Try Parallel coils (use thinner gauge wire like 28 or 30) for A real increase in surface area and a better performing atomizer all around.

 

[Hans Wermhat]

If that's an iStick 100W it's actually a parallel configuration, so yes you are splitting the amp load between 2 batteries. Be careful though. Those things will run off 1 battery if the other one pops loose or has a bad connection.

 

[Wake'n'Vape]

I just wanted to ask what you thought of the twisted build compared to the single you had, how does it VAPE!

I tried twisted and parallel dual coils both coming in at .3 and found vapour production to be very similar with both builds, maybe slightly better flavour with the parallel build but it's hard to say. Honestly i'm not even sure there is a massive difference between these builds and the 6 wraps of 26g I threw in when I first got it, apart from I actually found these builds even easier to throw together.

 

[Tommy-Chi]

Great question and some really great, detailed, answers. I'm not in any way in the same league as many of the posters above, having just dove in Sept 7th, 2015, but I would say this, go to YouTube and watch coil wrapping videos after you get settled in with your device and see what you can do.

There may be dozens of YouTube channels but right now the best channels that I know of for coil wrapping are: RiP Trippers; Twisted Messes; The Art of Vaping; Local Vape.

 

[Wake'n'Vape]

I have already found myself spending way too much time watching some of the Youtube channels you suggested, nevermind trying out new builds

I actually just posted a question in the coil building section but will put it here aswell.

So far i've had twisted, parallel and now dual claptons in there at .35 which seem to perform best imo. I have been using steam engine calc to work out how many wraps I need to be doing for each build, but now I want to try dual fused claptons 26ga wrapped with 32ga kanthal, how many wraps would I have to do in order to get .3-.4. Or am I aiming for too high a resistance with this type of build? If so how would a single coil build work out in the velocity?

 

[IMFire3605]

Just put a twisted build in it, was aiming for 0.4 but ended up a little over .3, yet to test it out properly as I just ran out of 3mg juice. Looking at the ohms law calculator its saying this build at 60w is drawing 14amps, i'm using a pair of LG HG2's in my iStick rated 20A. Is this load spread evenly over the 2 batterys, so 7amps each or does it not quite work like that?

iStick100watt, is a parallel battery configuration. So, max voltage is that of a single battery at full charge (4.2volts), but the load is balanced between the 2 batteries, so mAh and amps are double a single battery, the HG2's these figures would be 6000mAh (3000mAh X 2) and 40amps (20amps X 2, or 20amps per battery). Unlike a mechanical remember you have to do your calculations from the lowest battery charge state with a regulated mod, this instance 3.2v, so take your max wattage and divide that by 3.2v, iStick100watt that is 100/3.2=31.25 max amps, 31.25/2=15.625amps per battery. So even at full output you are safe on that mod with those HG2's

 

[IMFire3605]

I have already found myself spending way too much time watching some of the Youtube channels you suggested, nevermind trying out new builds

I actually just posted a question in the coil building section but will put it here aswell.

So far i've had twisted, parallel and now dual claptons in there at .35 which seem to perform best imo. I have been using steam engine calc to work out how many wraps I need to be doing for each build, but now I want to try dual fused claptons 26ga wrapped with 32ga kanthal, how many wraps would I have to do in order to get .3-.4. Or am I aiming for too high a resistance with this type of build? If so how would a single coil build work out in the velocity?

Roughly, 4 strands of 26awg in parallel, it will be a bit lower than with dual twisted 26awg, roughly you'd be looking at 2x coils in the 12full/11half to 14full/13half wraps configuration to get near inside the 0.3 to 0.4 range, maybe 13full/12half to add in extra room for the 32awg wrapping wire, wattage will be in the 80 watts 111 mW/mm²
Heat capacity (each coil) 59.75 mJ/K to 150watt 208 mW/mm²
Heat capacity (each coil) 59.75 mJ/K range to even really fire that set of coils.

 

[Baditude]

I follow the K.I.S.S. principle. (Keep It Simple, Stupid)

You may or may not notice a difference between a simple coil and an exotic coil build.

I'm an experienced vaper (nearly four years). I've worked in a vape shop before, where nearly everyone rebuilt their own coils. I've built and tried most of them, and to me I can't tell the difference in the way they vape. I don't particularly like making coils, so for me simpler is better.

If you find that you like to experiment and tinker, then by all means try the exotic fancy coil builds. It's just not worth the time and effort involved for me.