So...what is "sub-ohm" and can I get some build help?

[kalzoney]

First post/newb member

As the title says...what the heck is sub ohm? And how do I know if it's a sub ohm? What does it do? I've been searching and no luck..point me in the right direction

Also..I'm running a k100. I'm looking to build my own coils. I do have General knowledge on it but it's just the calculation I'm confused about (yes I've read ohms law and saw the calculator). I have some parts ready as of now.on hand I have A1 30g kanthal wire, and a igo w rba. I was wondering if I can use cotton balls as wick with an AW IMR 18650battery...how would this go about? Thanks in advance

 

[project_zao]

I use cotton from q-tips
And 30 gauge

With volt meter first short out your leads and get your internal resistance. Keep it in mind
Then google the resistance for the kanthal (i need to do this too)
Measure out how long the wire will have to be to get a coil to read under 1ohm. Say .8 or .6
So if your internal resistance is .5
And your coil measures out at 1.4
Then youd have a .9ohm sub(under) 1ohm coil

Latest hotness is micro coils. Heat up fast and you could do sub ohm easy with 30ga

Also on dripping you can use thicker kanthal 3 or 4 wraps and get sub ohm (say 28g)


I have a dripper simular to the igo w and have put 4 micro coils in on it at 2.4ohms with 30g

 

[bosun]

Kanthal A-1 Wire Specs: (Ohms Per Inch)

•28 AWG- 0.439 Ohms/in, 0.0508 Diameter (in.)

•30 AWG- 0.696 Ohms/in, 0.0100 Diameter (in.)

•32 AWG- 1.091 Ohms/in, 0.0080 Diameter (in.)

•33 AWG- 1.383 Ohms/in, 0.0071 Diameter (in.)

•34 AWG- 1.758 Ohms/in, 0.0063 Diameter (in.)

 

[vapero]

So the ohms per inch apply if I cut say 1 inch including the legs or just the micro coil?

Sent from my Galaxy Nexus using Tapatalk 2

 

[State O' Flux]

So the ohms per inch apply if I cut say 1 inch including the legs or just the micro coil?

You'll end up with about 3"+ to start.. so you have something to hang on to and wrap. When you've got it done, you'll have a coil, and over-long legs that you can cut off the excess after you've installed it, measured the resistance, and test fired it for shorts and hot spots... re-snugged the screws, and repeat until you're absolutely sure you've got consistancy.

Experimentation is what it's all about. There are no hard fast rules to wrapping you're own coils other than safety rules. A dead short isn't pleasant. Go to the RBA sub-forums and read... take nothing as gospel, see who's smart, and who's a braggart or and idiot... the smart ones tend not to brag or do stupid things, or come up with idiot names for "their" coil.

You need at minimum, a APV that will read less than an ohm, or a DMM, or a basic ohm meter. I'd suggest a DMM... then you can test battery voltage and mech continuity too. If you want to play with sub ohm, you need to know exactly where you're at.

I may be a bit over safety conscious, but for n00bs, its better to take it slow than "smoke" something.

Welcome to the asylum kalzoney... and have fun!

 

[Anesthesia]

An Ohm meter should definitely be the next thing on your shopping list. Then, I'd recommend just watching some youtube videos about building the particular coil you're going for. I started out with a single coil on my Igo-W until I moved to 32g kanthal because of the dual dividing it in half. After I played around for a bit and went through about 8 different coils I found a nice setup for it.
Grab a bag of organic cotton, then boil it for a bit (and dry) just to make sure you won't be vaping any pesticides or cleaning chemicals that it might have met on it's way to you.
Just tried out a micro coil with 12 wraps and cotton ball as the wick in my protank II last night and it's been treating me amazing

 

[DoogieTony]

Sub ohm simply means that your coils resistance is less than 1 ohm, so 0.9 and under is sub 1 ohm. It can be dangerous so you need to KNOW what you're doing not just have general knowledge.

If you are going to try this you need a multimeter to know your resistance and check for shorts.
You need to know how many amps your battery can handle, so find It's C rating multiply by the mah and divide by 1000. That will five you the batteries max amp limit.

It's best to leave a large amount of wiggle room below your batteries limits.
Use the ohms law calculator to figure out your amp draw.


To use cotton balls for wick, you'll just wrap a coil on something like a 1/16" drill bit, insert your coil, check its resistance, pull a small piece of cotton off, and thread it through the coil. After that just soak with liquid and vape.

With cotton balls you only need a small amount of cotton to wick well, so when you thread the wick through you just want it to barely touch the inside of the coil.

 

[project_zao]

So the ohms per inch apply if I cut say 1 inch including the legs or just the micro coil?

Id like to hear more feedback about this question. Seems that with the coil being more tightly packed the resistance mesurements change, no?
Age of the coil can add a few decimal points to your coil, dry firing will fix that, sometimes i can tighten a bit more to and that helps lower it back.

Ill ask the above question to BSD. But i would think the legs lenght plays a minimal part. It should be nice and squared off and fit well into the posts. Figuring out what works as an internal diameter to wrap your coil on gets tricky and will be different with each atomizer you build.

But its fun to experiment! Keep an ohm meter on and have a coil wrapping day!

 

[Baditude]

Using the proper battery for Sub Ohm is essential. All RBA/RDA's need a high quality IMR or IMR/hybrid battery (see list below).

Using a Sub Ohm coil < 0.8 ohm you should use one of the higher-amp IMRs with a continuous discharge rate of 20 amp or more (again refer to list). I strongly recommend making your first several coils at > 1.0 until you have gained enough experience to be safe and consistant.

Never exceed what your battery can provide safely, and allow for some safe wiggle room on top of that. Coil resistance can change for no apparent reason, so the resistance needs to be checked with a digital multimeter on a regular basis.

Use the Ohm's Law Calculator to insure your battery can fire the coil safely within its limits. Refer to this post for more details: http://www.e-cigarette-forum.com/forum/general-e-smoking-discussion/480857-battery-help.html#post11008295

AW IMR
18650 2000mah 10Amp CDR
18650 1600mah 24A

MNKE IMR
18650 1500mah ​20A

Panasonic ​or Orbtronic hybrid
CGR18650CH (IMR/hybrid) 2250mAh 10A
NCR18650PD (LiNiCoAl) 2900mAh 10A
Orbtronic 18650 SX22 (hybrid) 2000mAh 22A

Samsung hybrid (LiNiCoMnP)
INR18650-22P 2200mAh 10A
INR18650-20R 2000mah 22A

Sony
us18650v3 IMR 2250mAh 10A
us18650vct3 (hybrid) 1600mAh 30A

Efest IMR
18650 (IMR/hybrid) 2250mAh 10A
18650 2000mAh 10A
18650 1600mAh 30A​

CLOUD CHASING IS DANGEROUS! <-- Please read!

Mechanical Mod Proper Usage Guide

Battery Basics for Mods: IMR or Protected?

Information Resource Guide for Your First RBA

Do your research and homework prior to using an RBA. Don't attempt Sub Ohm until you have been successful making normal resistance coils first. Consider the alternative to Sub Ohm with Micro Coils, which is safer with similar results.

Make sure that you own and know how to use a digital multimeter. If you don't, you have NO BUSINESS wrapping your own coils. Coil resistance can change for no apparent reason, so its vital to check it frequently.

Respect the power in batteries. All batteries are dangerous if not used properly. Below is an AW IMR battery that hard-shorted and went into thermal runaway. What you see is what remains of the metal casing, and the contents of the battery blown out like an accordian when the battery vented. You can only imagine what this would do inside of a metal tube like a mechanical mod.

 

[kalzoney]

Thanks for the help..now I have a better understanding of sub ohms...Will deff need to invest in a few accessories