Coil Diameter - Whats your preference?

Discussion in 'Coil Building' started by ren.dnb, Jul 27, 2015.

  1. ren.dnb

    ren.dnb New Member

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    Hello Everyone,

    I'm fairly new to Vaping Underground but not so much to vaping (been a hybrid user for about 2 years and about to make the switch THIS WEEK to 100% vaping!). I recently changed over to an RDA and I totally in love with it. Coil building is something I dabbled with earlier this year after I got my Kanger Sub Tank mini. Now I'm just a coil builder and don't see any other way of doing things. But I have a question regarding diameter of the coil.

    I've been using Steam Engine to help me with the number of wraps and have played around with the numbers. I like to use 26 gauge kanthal as it gives me the ramp up time I like with a dual coil build. I typically run between .3 - .4 ohms at around 45 - 50w. This weekend I wanted to make a build on my rda that was closer to .3 ohms. According to Steam Engine, that was about 6 wraps or so at a 2.0mm diameter.

    My thought was "hey I should try to get more wraps in for more surface area" so I shrunk up the diameter to 1.5mm. That gave me about 7 wraps or so to play around with. I noticed however that I had to cut my wicks thinner.

    My question is, does diameter matter when it comes to the coils? And does surface area matter? I'm using a mutation x v4 as my rda. I think I've hit my sweet spot, but if I could be doing something better (without getting all fancy with a wrapped coil), I'm all ears! If diameter doesn't really matter, nor does surface area, I might just stick with the 5 - 6 wrap 2.0mm diameter coils.
     
  2. Thunderball

    Thunderball Gold Contributor Member For 3 Years

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    Im of the belief that the more surface area you have, the more juice you have that heats up to make more vapor. I also think that the larger the piece of cotton you have the more you can non stop vape because it holds more juice keeping your coil wet which is the reason you have a wick in the coil in first place.

    I could be wrong but thats my opinion and my two cents. :)
     
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  3. Neunerball

    Neunerball Platinum Contributor Member For 3 Years ECF Refugee

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    My personal preference is an ID of 2.5 - 3 mm. It helps the wicking at higher wattage. Dual coil 24g 7/6 wrap 2.5mm ID => 0.32 Ohm
     
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  4. Haadkoe

    Haadkoe Bronze Contributor

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    2.5-3mm is my sweet spot as well. Usually single coil 22ga @ .3-.4 ohms on a mech.

    Vertical in Veritas and Marquis, horizontal in derringer and dark horse. Wicked with rayon cotton balls.

    Flavor and clouds are on point, and I never get dry hits. I can taste the flavor fall off long before it goes completely dry. Flavor changes are almost immediate when switching juices.

    I recoil basically never, and rewick whenever I decide it's time, which can be 2 or 3 weeks depending on how gunky my coil gets.

    At this ohm range, with this wire and wicking, at this diameter, I literally never scorch my wick. Never burn the material inside the coil leaving just the tails, murdering the flavor, like I constantly did with cotton.

    Life is good. No tc required, really, although I plan to venture into that arena as the market matures.
     
    Last edited: Jul 27, 2015
  5. robot zombie

    robot zombie Silver Contributor Member For 2 Years

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    If the resistance is the same, but the diameter is reduced, then you haven't gained any surface area. What you're left with is the same amount of metal and the same amount of wick making contact. The only difference is that you will have less wick retaining juice across a longer coil.

    Coil diameter can make or break your build. Micro, macro, and nano have different heating and wicking properties. What size works best tends to depend on two factors: how much airflow you intend to allow and how much power you're giving to your coils for the amount of surface area they have, though I suppose it really all comes down to the absorbency of your wicking material. So it all matters, really. You have to strike a balance between competing forces in order to get the best performance.

    Micro coils are fine if you're building to a high resistance with thinner wire and less airflow - small, low-power, low-surface-area coils. It helps the smaller amount of wire retain heat for bit longer and vaporize more juice in a shorter amount of time. Wicking efficiency is not as much of a concern because you're going to be using less airflow and the amount of heat that the coils can generate/juice they can displace is greatly limited by their size/surface area. They are wicking slower and vaporizing juice slower. Too much wick can easily choke them and keep them from heating up properly, which in turn slows the whole system of interacting forces down - your juice can only wick as fast as the coils burning it allow it to.

    Micros can also work well with twisted or claptoned wire at higher power levels. There may be considerable heat and surface area from a numbers standpoint, but because the coils themselves have some passive wicking properties and slower ramp-up times to fight against, a smaller diameter may be more desirable to both decrease ramp-up and minimize spitback. You can get away with less wick because the coils can retain and displace some juice within themselves, which keeps them cooler, watt for watt.

    Macros are more effective when building with thicker wire at lower resistances. With all of the heat those coils are capable of generating and retaining across their large surface areas and the amount of airflow necessary to keep them under control, they can sometimes pull juice from your wicks faster than it can move through your wicks, so the extra reserve and lower friction afforded by a wide interior diameter is necessary to prevent the coils from overheating.

    Otherwise, the heat from the coils may displace juice faster than the capillary action drawing the juice through the wicks can replenish it.
    Not only will your wicking material potentially start to burn, but your juice will too. Well-saturated wicks function as a cooling system to keep that from happening. Horizontal width is also a concern. Make them too wide, and the juice may not be able to cover the distance in time to keep the center wraps from overheating. Sometimes, it is more prudent to increase diameter instead of wraps when increasing surface area.

    Nanos are a bit special. They're meant to capitalize on the outer surface of the coil. By wrapping wick around the outside of the coil, more wick makes contact with the coil than traditional methods allow for. This offsets the large amount of heat generated as a result of the miniscule ID and allows a tiny coil to deliver heaps of flavor and vapor. In a way, it's extremely efficient, but finnicky.

    All that being said it's mostly trial and error that'll get you what you want. That's how I learned, anyway. There's a lot I'm not accounting for here.


    Personally, I run 22 and 24 at around .2, so I tend to only build macros. 3/32 seems to work pretty well with japanese cotton. That's just below 3mm. Sometimes I go up to an 1/8th for the 22g because it gets so hot and they don't wick as well when you start getting past 7 wraps.
     
    Last edited: Jul 28, 2015
  6. ren.dnb

    ren.dnb New Member

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    Thanks everyone for all the awesome replies! So I do own 24g kanthal along with my 26g kanthal, and I use japanese cotton as well. I think with all the information given so far, and anticipating what I'll see later on this evening, I'm going to ditch the 1.5mm coils when I get home from work. I've noticed I do have to drip more often with the smaller amount of cotton in there. I really liked how the 2.0mm id builds were going, but started to get curious over surface area and more wraps per coil.

    Everyone here especially robot zombie really helped explain the physics of it and thats mostly clear in my mind. I just have to put it all to practical use now. I'm going to shoot for .3 ohm on 26g at 2.0mm id. That should be around 6 wraps or so. Looks like I had what I needed this whole time.

    I would go to 24g wire, but my issue with that is it takes longer to heat up with the thicker wire =/ I'm assuming there's no real work around for that? Just the initial ramp up time is going to be slightly longer due to the thicker wire?

    And thanks again guys... this novice coil builder definitely appreciates everything.
     
  7. robot zombie

    robot zombie Silver Contributor Member For 2 Years

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    Well... ...yes. Although it has lower resistance per foot, there's also a lot more metal for the power to move across, so it takes longer to heat up. Bear in mind that it will also reach higher temperatures overall, so it can be made to generate as much vapor as your wicks can accommodate. That's the main appeal to it. The amount of surface area and heat gives you an edge-up in flavor, vapor, and temperature, even if it is a bit laggy.

    There are workarounds if you want a shorter draw, though. You can either compromise a bit of surface area to bring the resistance down and increase the amount of current (that's why I build so low with it,) or you can bring the voltage up.

    Another option is to close-off the airflow a bit. Less air cooling the coils will make them heat up faster, though because thicker wire retains heat for longer, your vape will get progressively hotter with extended use.

    EDIT: I thought of something else about diameter. I've noticed that I tend to build to wraps rather than the diameter. 4-7 wraps is my range. The exact amount of wraps is a minor tweak for hitting a better balance between surface area and heating properties at the diameters that are able to give me the power I'm shooting for at that range of wraps. Once I hit the power that gives me the heat I want, I adjust my wraps to maximize surface area, flavor, and ultimately, wicking efficiency. The key in experimentation is to keep one constant and tweak the other parameters to match your hypothesis. From that, you can draw meaningful conclusions by comparing results and expectations. That taught me a lot about diameter and wicking.

    The thickness of the wire and desired power range will determine the diameter. For instance, if I need less power, I will build a single at 5-7 wraps with 26-28. If I want more, I will do the same amount of wraps, possibly in a dual configuration, only with 26-22, depending on how much heat and surface area I want. Obviously, the latter build will have a greater overall temperature and diameter. Different wire thicknesses perform optimally at different power levels and diameters. Generally-speaking, the thicker your wire and greater your wattage, the wider your diameter.
     
    Last edited: Jul 27, 2015
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  8. Neunerball

    Neunerball Platinum Contributor Member For 3 Years ECF Refugee

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    If the ramp time is too slow for you, you can increase the wattage on your device.
     
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  9. ren.dnb

    ren.dnb New Member

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    Yeah I messed around with that on my m80 plus. It will go to 80w max, but judging from Steam Engine, looks like I have a mild excuse to buy that new smok x cube II lmao, and enter the world of 100w + mods. Looks like I'll get the results I need from the device though, as I just have to crank it up to 75w with the 24g wire as opposed to the 45-50w with the 26g wire.

    I hate running a device so close to its max output but then again.... it was designed that way for a reason. Just got done with a build just now, bumped back up to 2mm id and got .4 ohm with about 6.5 wraps per coil (26g wire). Think I'll roll with this for a week and see how it works out. I tend to lean towards a warmer vape so this config is right in the middle (running it at 45w right now).
     
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  10. conanthewarrior

    conanthewarrior Gold Contributor Member For 3 Years

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    I have a driver that has a grip in JUST the right place that makes wrapping coils extremely comfortable. It is 2MM.
    So most of my coils are 2MM, although I am finding 3MM to be working better with experimentation. I may get a 2.5MM driver so it is in between the two.
     
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  11. ren.dnb

    ren.dnb New Member

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    I cheat now when it comes to coil wrapping. I used the little screwdriver that came with my subtank for awhile. Recently tho, I was looking for some wire cutters and putting together a tool kit for coils. So, I ended up buying the coil master tool kit.

    The coil wrapper with that kit makes it almost too easy to make coils lol. But yeah, I've been using the coil master for about a month now. Definitely love it, and will probably buy the upgraded model in a couple of weeks (they give you the old version of the coil master with the toolkit... go figure).
     
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  12. scarecrowjenkins

    scarecrowjenkins Silver Contributor Member For 3 Years Unlisted Vendor

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    Forgive me if this has been mentioned, i quickly skimmed over the replies but if you're looking to increase the surface area you could always consider a lower resistance wire such as nichrome. The lower resistance cuts down on ramp up time while allowing you to add some extra wraps to your coils for better everyyything :p jacobs-online.biz sells awesome nichrome 80V for real cheap. Worth the $10 risk if it means finding a build you really really enjoy imo. Regardless, good luck! You've gotten some stellar advice here on this one!!

    Edit~ for most coils i personally use a 2.4mm inner diameter. Seems to work well on very absorbent coils (fused claptons etc.) With straight wire coils i use a slightly larger 3mm diameter for the reasons @robot zombie explained. It all boils down to personal preference, so just take note of everything you do so you can easily recreate it when you hit the jackpot! :p
     
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  13. VapingN252

    VapingN252 Bronze Contributor Member For 2 Years

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    on RTAs I prefer 2mm for airflow sake. On RDAs, I do 3 or 3.5mm.
     
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  14. conanthewarrior

    conanthewarrior Gold Contributor Member For 3 Years

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    Is this one of those coil winders that winds for you? I have seen them, and was going to buy the whole set as its so amazing, and it seems to make perfect coils a bit easier. Its kind of like a rotating shaft, with a wider handle, that has a lid for when you are finished?
     
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  15. conanthewarrior

    conanthewarrior Gold Contributor Member For 3 Years

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    I will try the difference on my Lemo V2. At the moment it has two 2MM chimney coils, and it tastes great. With a thin drip dip, it is more flavour than the nautilus mini ever provided me, and that is known for taste.

    I generally find they pack RTA's with an all rounder drip tip, so its a bit of flavour and a bit of cloud, not strong to one side or the other, to keep most people happy with a big cloud and a hint of flavour, you then have to choose your own tip for it.

    I'm a flavour guy so thin always wins, although I do go mad on my RDA'S occasionally and make my house look like there has been a rather large fire lol.

    I'm not happy though, as I lost my best thin drip tip. I am using the nautilus tip now on my Lemo, which is great, but not as good as this £2 one I had. Only good thing is I can order more from the shop which is good :).

    EDIT: I know I was replying about coil diameter, but thought I would add my thought that I, and my fiancee, both find on drip tips. Its like a smaller one concentrates the flavour.
     
  16. ren.dnb

    ren.dnb New Member

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    Yeah its basically a coil winder. Stick the wire in one end and theres a cap that you rotate that pushes the wire around the metal shaft and winds a 99% perfect coil. I ended up buying the whole coil master DIY kit with cutters, pliers, tweezers, and their coil winder (coil master). They made a version 3 of the coil master thats bigger and makes things a bit easier from what I can tell. But so far what I got is working out just fine for now.

    That being said, their version 3 of the coil master has larger diameter metal posts to wrap around on, and you can wrap clockwise or counterclockwise so, there are more options with the newer product. I just needed a set of tools as my kids were getting into my vape box and taking my stuff lol.
     
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  17. BoomStick

    BoomStick Gold Contributor Member For 3 Years

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    For a dual coil rda build I like 7/64" - 1/8" (2.7mm - 3.1mm) diameter, 24g, and 5-7 wraps. When using a variable power mod I use the upper end of those ranges. With a mech the exact specs depend on the conductivity of the gear.
     
  18. Myk

    Myk Silver Contributor Member For 3 Years

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    I believe in more surface more vapor.
    I believed in micro coils for a while. Then I figured out with gennies/mesh bigger wick allowed more vaping and applied that thinking to subtank and drippers.
    I switched to larger diameter coils, still touching.
    I switched from touching with temperature control, but I haven't figured out what matters and what doesn't with TC, just that touching can screw it up.

    Smaller diameter isn't giving you more surface, only more wire does that.
    Remember coils don't heat evenly, too long of a coil will dry the inside of a small diameter wick before the heat gets to the outside of the coil. I ran into this trying to get ribbon micro drippers to 2Ω.

    I was enjoying 30ga and ribbon micros, about 1mm, 1.5Ω. Then I liked 26ga touching, 3-3.5mm, 2Ω.
    The 26ga/3.5mm can take a lot more watts without drying out.
     
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  19. huston

    huston Member For 2 Years

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    i use 7 wraps 26g per side 2.5 mm gives me about a .46ohm
     
  20. smacksy

    smacksy Platinum Contributor Member For 3 Years

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    I like 3.0 mm myself..
    22, 24 and 26g micro coils work best for me..sometimes dual parallel 24g for clouds ..all 3.0 mm ID...Dripping of course..

    sent from my XT1080 via Tapatalk
     
  21. death2fake

    death2fake New Member

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    I love dual parallels at .15. I use 26 awg. On a 1.92mm id. For me parallels are very easy to make and create a very flavorable,thick, hot vape that I love. I never tried them for the purpose of cloud chasing. If you want flavor; put that build on a mutation x v4 close the sides up and prepare to get smacked in the mouth with whatever your favorite flavor is.
     

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