Dual coil school, come on in guru's...share your knowledge!

[KillTheNoise]

Alright I'm taking the next step in the rebuildable world. I've mastered tanks and drippers of mesh, hybrid, and silica alone, I've mastered wrapping single coils to whatever ohm I want, and I'm getting bored!

I've looked at a few posts and videos, but I would like the help of the all-knowing community here.

1. When wrapping the wire...does resistance add or subtract from wire to wire? (wrap two .6 ohm coils > you meter @ .3) or the other way around?

2. Single wire coils or use two separate pieces of wire for each wick?

3. Should I be more careful with my batteries? I always change and recharge around 3.6-3.8 volts left...would I be safe keeping this habit? (I use strictly MNKE 18650s.)

4. Does EVERYONE using a 2+ coil build have more than 1 air hole in the cap?

I will be using 28g kanthal a1 and 3mm silica and wrapping it on an AGI drip mode. Any tips, tricks, or tutorials would be incredible!

Thanks!

 

[grindle]

1. 2 x 0.6ohm = 0.3ohm

2. Depends on the atty and where you want the second coil, but most drippers I've come across have been easier to work with placing two separate coils on the same side. A Genni is easier to wrap with a single wire - up one wick, posi-post, travel down the other wick.

3. That's a nice habit but not strictly necessary. If you don't mind charging more often, keep doing it.

4. No, that's a more recent thing that seems to appeal to the cloudhounds, I use my second coil as my TH-deliverer but I understand that (or forums make it seem like) Americans seem to like airier, less throathit-y drags, hence the dual airholes, or the drilling airholes out to 3metres wide.

 

[grainey1968]

1. 2 x 0.6ohm = 0.3ohm

2. Depends on the atty and where you want the second coil, but most drippers I've come across have been easier to work with placing two separate coils on the same side. A Genni is easier to wrap with a single wire - up one wick, posi-post, travel down the other wick.

3. That's a nice habit but not strictly necessary. If you don't mind charging more often, keep doing it.

4. No, that's a more recent thing that seems to appeal to the cloudhounds, I use my second coil as my TH-deliverer but I understand that (or forums make it seem like) Americans seem to like airier, less throathit-y drags, hence the dual airholes, or the drilling airholes out to 3metres wide.

All great answers Grindle. You are obviously faster at typing than I. I agree with all of them! BTW - not all yanks like the airy drag! I prefer it a little tight and more TH.
Thanks dude!

 

[Aoi~]

1/R_eq=1/R₁+1/R₂+1/R_n

The formula to calculate the equivalent resistance when doing parallel coils.

The shorthand (R/2) works if you have two identical coils, which you will want, otherwise, one coil will burn brighter than the other.

Do try to use a good battery. I usually look at the Continuous Discharge rating on a battery and try to give myself a good cushion from the max rating compared to the calculated amp draw of the coil I build.

ETA: Amp draw is calculated at each coil, and added together, NOT from the equivalent Resistance.
So if you have 2x 1Ω coil, the equivalent Resistance is 0.5Ω, but the amp draw with 4.2V battery is 4.2A@each coil = 8.4A total for the circuit (This is all calculated numbers, you will have internal resistance of the battery, of your mod, whatever)

 

[Phil McRotch]

I'm not a dual coil expert, but I can answer a few of your answers.

1. The number of ohms per coil gets divided by the number of coils you have; i.e. two 0.6 ohm coils = 0.3 ohms.. quad and six coils go above my head, so I'm not sure if that math is still valid, like four 1.2 coils = 0.3 ohms or whatever.

2. It's usually separate pieces of wire per wick.

3. Yes. Battery drain will expectedly be faster with the lower ohms. Your habit and choice of battery are fine =)

4. I usually see 2 air holes on opposite sides, but I have seen quad coils with 4 holes once.. as long as the air holes are lined up with the coils.

I don't drip anymore, so I don't have any dripping RBA's or tips for ya.. sorry, bud. But I have seen vapelyfe vids on dual/quad coiling on youtube. Worth checking out.

 

[grainey1968]

1/R_eq=1/R₁+1/R₂+1/R_n

The formula to calculate the equivalent resistance when doing parallel coils.

The shorthand (R/2) works if you have two identical coils, which you will want, otherwise, one coil will burn brighter than the other.

Do try to use a good battery. I usually look at the Continuous Discharge rating on a battery and try to give myself a good cushion from the max rating compared to the calculated amp draw of the coil I build.

Great point about the identical coils. Try and use (as much as possible) to use the same size and length of wire for your coils to make it a little easier for your build.
Thanks Aoi

 

[grindle]

I prefer it a little tight and more TH.
Thanks dude!

I knew there'd be an exception! All I see is talk of 1.5-2mm airholes and above so it's probably a misrepresentation from all the SLR experimentation that goes on. I got one of those updated iGOs - it turns out some yanks complained about a tight draw so they revised and drilled it to 1.2mm and I'm still getting used to it. Very airy for me.

 

[grainey1968]

I knew there'd be an exception! All I see is talk of 1.5-2mm airholes and above so it's probably a misrepresentation from all the SLR experimentation that goes on. I got one of those updated iGOs - it turns out some yanks complained about a tight draw so they revised and drilled it to 1.2mm and I'm still getting used to it. Very airy for me.

Unfortunately, more and more people are looking for blowing major clouds! Probably from all the videos and blogs from the guys in the Philippines letting us Americans fell pretty joe average with the size of our plumes! Manufacturers know that adding a bigger air hole help with this. I much prefer getting my taste and TH!!

 

[KillTheNoise]

Okay so I have one built.

http://imageshack.us/a/img197/6673/imag0223ek.jpg
http://imageshack.us/a/img12/1647/imag0226v.jpg

Using one wire of 1/2 wrapped 28g kanthal and two 3mm pieces of silica. Still getting .9-1.0 ohms...I don't get it! :/ There is vapor, but not like I would expect...and a way bigger TH then there should be. Also, this is on a 4.10 volt battery, so pretty much fully charged.

Somethin aint right!

 

[Aoi~]

Okay so I have one built.

http://imageshack.us/a/img197/6673/imag0223ek.jpg
http://imageshack.us/a/img12/1647/imag0226v.jpg

Using one wire of 1/2 wrapped 28g kanthal and two 3mm pieces of silica. Still getting .9-1.0 ohms...I don't get it! :/ There is vapor, but not like I would expect...and a way bigger TH then there should be. Also, this is on a 4.10 volt battery, so pretty much fully charged.

Somethin aint right!

That picture looks like it's sitting in series, if you look at the long line between the coil. 1/2 wrap of 28g would be like 0.2-0.3 ohms in parallel.

This is something I put together today with 32g and 3mm ekowool

 

[KillTheNoise]

Does sitting in a series calculate different than two separate parallel coils?

I tried two parallel coils and whenever I went to tighten the screws down it would pull/twist the coils up and ruin everything. What can I do differently?

 

[Aoi~]

This one is on an IGO-L (2 posts). It's 30G kanthal + 3mm silica if I had to guess. I believe in having more wraps (more surface area of the wick heated) that's why I usually use the thinner wires when doing dual coils.

 

[Aoi~]

Does sitting in a series calculate different than two separate parallel coils?

I tried two parallel coils and whenever I went to tighten the screws down it would pull/twist the coils up and ruin everything. What can I do differently?

When the coils are set up in series, the equivalent resistance = R1 + R2, they add, that's why you measure 0.9-1 ohm. You can twist the ends of the wire together to make it easier to connect to the post.

 

[grindle]

Sitting in series is just one long coil.

If you're determined to keep it as one single wire, loop the middle of the wire around the positive post and screw that down. Start wrapping those legs onto the wicks on either side with each leg ending their journey at the negative post. It'll help if each leg is wrapped around that negative post clockwise so that when you screw them down they won't be pushed out from under the screw. This should trap them.

 

[KillTheNoise]

Going to give two separate coils a go...I will report back after my findings!

I WILL GET THIS TONIGHT!

 

[KillTheNoise]

GOT IT!

two 3/2 coils of 28g kanthal...it took a good while to get right, but DAMN! I can barely vape my 20mg pluid but the 12mg G2 isn't too harsh! Time to look for some cutter?!

Thank you everyone who has input some knowledge...and if you're here reading, hoping to learn something about making dual coils, STICK TO IT! You CAN get it!

WOW

http://imageshack.us/a/img109/4312/imag0227n.jpg
http://imageshack.us/a/img856/2161/imag0228fi.jpg