3 post RDA, serial coils?

[EmeraldLeo1982]

Ok so I'm preparing myself to my new RDA that's in the mailboat somewhere...

I've got Kanthal A-1 0.4mm x 0.1mm Ribbon wire with a resistance of 0.9 ohms per inch.

I want to setup dual coils in my new 3 post dripper. But running them in parallel would be HUGE coils to achieve the right ohmage. 2x 3.6ohm coils would be about 8 inches of wire inside a v10 ( http://www.fasttech.com/products/1408901 ) and I just don't see how that would work out. So I'd like to see how somebody would do dual coils in series with a 3 post setup. I've been searching all over but I can't seem to find a picture of series coils or instructions.

Any help is much appreciated =D

 

[EmeraldLeo1982]

Nobody uses serial microcoils?

 

[pdxtechdoctor]

A couple of comments..

What makes you think you need it to be at 1.8 ohm?

Also I'm not sure that ribbon wire is the best for this application. I'm not saying it wont work, but normally round wire is used to build a mircocoil. it makes it much easier to make sure that the wraps are touching each other which is what you want in a microcoil.

If you are trying to wrap for a device with an ohm limit, get some higher resistance wire...

 

[EmeraldLeo1982]

well I want 1.5-1.8 for safety reasons, and there's really no good reason to go any lower then that.

I stuffed a nice mini/microcoil into my CE4 with the ribbon and I love the way it produces. I would have gotten smaller gauge ribbon but 0.4mm was all I could find for a decent price on ebay. Got it from TEMco and it's the smallest they carry.

and the surface area on a 4/5 ribbon coil is roughly equivalent to a 12 wrap small gauge regular wire coil. I haven't had any issues with getting my coils microgapped but I have alot of patiece and don't mind spend 2+ hours getting my coil right, and good eyesight helps.

But really I don't understand why I can't find any info about building serial dual coils. With 2 post or 3 post setups.

 

[WattWick]

Won't a serial coil require 4 terminals? I might be exposing my lack of cleverness here, but I don't see how you can wire 3 posts in any way other than what people call parallel.

 

[EmeraldLeo1982]

I don't know personally, but I know people can do serial quads with a 3 post. Not sure exactly how serial works vs parallel. I know once doubles the resistance(serial) and one halves it(parallel). I've been trying to think of how to link 2 coils together with a 3 post but can't fiure it. But I'm also far from anything resembling a master electrical engineer.

Is it possible to just use 2 of the 3 posts? or would leaving the 2nd Neg. post open cause issues?

I'm also wondering what the inside area of this RDA is? Anybody care to mention the average inside area of a 510 RDA? It's the v10 from fasttech, not sure what exactly it's a clone of. But I've never messed with an RDA before or anything else bigger then this CE4 I've got. I'm guessing it's about the size of a US Quarter?

I'm rolling up a coil of 3.25" at the moment to see how large it will come out. which would give me 3 ohms(+/- .05) I'll post a pic once it's done.

 

[Statistic]

well I want 1.5-1.8 for safety reasons, and there's really no good reason to go any lower then that.

There isn't any more reason to do multiple coils than there is to make one that's <1.5ohm

If you are wanting to make multiple coils in series then you won't want to use more than two posts, unless I am missing the point.

 

[ZeroDisorder]

Well, you have two things to consider. You need a good bit of current to heat that much coil, in the case of the 3.6 ohm case, you'll be getting less than an amp assuming ~4V. W=R*I^2

Why do a series coil when you could do one big one? That's really the same thing... With three posts, you'll usually have 2 "negative" and 1 "positive". For a series without splicing coil to coil(bringing the thought of one big coil) you couldn't really do it. You'd have to have one isolated post to do a series connection using the posts to splice them.

 

[EmeraldLeo1982]

There isn't any more reason to do multiple coils than there is to make one that's <1.5ohm

If you are wanting to make multiple coils in series then you won't want to use more than two posts, unless I am missing the point.

Guess you posted right as I edited to add the question about just using 2 posts. I mainly want dual coils for increased production as what I've been getting from 1.7ish ohms at 3.7ish volts isn't satisfying enough for TH/Vapor, but mainly for TH.

 

[EmeraldLeo1982]

Well, you have two things to consider. You need a good bit of current to heat that much coil, in the case of the 3.6 ohm case, you'll be getting less than an amp assuming ~4V. W=R*I^2

Why do a series coil when you could do one big one? That's really the same thing... With three posts, you'll usually have 2 "negative" and 1 "positive". For a series without splicing coil to coil(bringing the thought of one big coil) you couldn't really do it. You'd have to have one isolated post to do a series connection using the posts to splice them.

I'm shooting for a 1.8ish total ohm setup, so I'd need 2 3.6ohm in parallel or .9 in series. either way as far as I know will pull around 2.05amps at 3.7 volts. Unless using the dual coil setup somehow changes the amp draw even while using equal resistance to single coils.


EDIT: Just for clarification, I'm not intending to argue with anybody at all. I'm just trying to clear up my own confusion. Thank you all for your inputs.

 

[Statistic]

What device are you putting this RDA on when you get it?

I understand your end goal but I think you're thinking about wrong. Like ZeroDisorder said this series coil is going to heat up slower and there really isn't any advantage to making two coils in series as opposed to making one really long coil. I think ultimately you may not have the right materials to achieve what you want to achieve (more vapor, better vapor).

 

[ZeroDisorder]

Guess you posted right as I edited to add the question about just using 2 posts. I mainly want dual coils for increased production as what I've been getting from 1.7ish ohms at 3.7ish volts isn't satisfying enough for TH/Vapor, but mainly for TH.

Then your challenge is of a physical one, not electrical.

I'm shooting for a 1.8ish total ohm setup, so I'd need 2 3.6ohm in parallel or .9 in series. either way as far as I know will pull around 2.05amps at 3.7 volts. Unless using the dual coil setup somehow changes the amp draw even while using equal resistance to single coils.

I was modelling it from each coil's perspective. Kirchhoff's current law, etc.

My thoughts would be to make a large U coil, unless you want to use something like NR wire across the gaps from one coil to the other. I'm not sure of the effects of having a "hot leg" between the coils using resistance wire. My thoughts are that it would heat up rather quick without juice around it, effectively instantly burning any nearby vapor. Again, I'm not sure about this though.

 

[Statistic]

Ribbon is fun and seems like it would be great for vapor production due to the flat surface but, in my experience it doesn't hold a candle to round wire. You should come check out the micro coil thread.. I think the results you seek can be found with a micro coil, you just might be blown away

 

[EmeraldLeo1982]

It's going on a ego-VV 1100mah 3-6v battery. Woul....

Just had an idea. Would it be possible and/or safe to run the coils at an angle in between the pos and neg post? might make it easier to fit in 3.25 inches of wire as opposed to putting the coils outside the posts. My only worry would be shorting? what if the coils were elevated to sit above the post like this?
/O\ /O\
[] [] []
Side view looking through the center of the coils.

 

[EmeraldLeo1982]

I'm using a micro I made with ribbon at the moment I love micro's.

 

[ZeroDisorder]

Doesn't sound half bad. My only thought at that point is airhole alignment may be a bit off. Since it's not "extreme" vaping, you may not have too much of a problem, but ideally you would want them aligned. Give it a try!

If you're connecting one leg of each coil to the center post, and one leg to one of the outside posts, you're making a parallel connection. Just be aware. For series you could do:

/OO\
[]__[]__[]

Making a short section (read: short) section between the coil ends would not cause a problem from what I've found.

Top conceptual view:

--______
--__--__
--__--__
--__--__
---|---|
--O---O---O


-- is space
_, | is coil
O is post

 

[EmeraldLeo1982]

Haha those would be some crazy looking coils. Call it the Twin Towers build! lol

Here's a pic of the coil I just wrapped. It's 3.25" of .4mm Ribbon measuring right around 3 ohms. Would it be achievable to fit 2 of these inside a standard size 3 post RDA?

EDIT: I know there's a couple kinks in it, my actual coil would be a bit cleaner. I was in a hurry here.

 

[ZeroDisorder]

Haha those would be some crazy looking coils. Call it the Twin Towers build! lol

Here's a pic of the coil I just wrapped. It's 3.25" of .4mm Ribbon measuring right around 3 ohms. Would it be achievable to fit 2 of these inside a standard size 3 post RDA?

I don't know? It should fit in an Igo-W. Which one are you thinking about? The thing is, you're not even using the third terminal for a series connection.

 

[Statistic]

Haha those would be some crazy looking coils. Call it the Twin Towers build! lol

Here's a pic of the coil I just wrapped. It's 3.25" of .4mm Ribbon measuring right around 3 ohms. Would it be achievable to fit 2 of these inside a standard size 3 post RDA?

EDIT: I know there's a couple kinks in it, my actual coil would be a bit cleaner. I was in a hurry here.

edit - DISCLAIMER - you really shouldn't be doing this on an eGo type battery unless you are aware that shorting it out will almost definitely render your battery useless, or worse. You are taking a risk by using your eGo battery to power an RDA let alone dual coils. If this is your only device you may want to reconsider this whole endeavor until you can do it with more durable and appropriate hardware

Yeap. If you are going for better vapor production and are determined to use ribbon wire and two coils then that's the way to do it.
Put two of those in your atty, parallel, for an overall resistance of 1.5ohm.

Be careful to make sure your connections are super tight and no shorts anywhere or you're gonna fry that battery.

 

[ZeroDisorder]

I got kind of caught up on the design and what I'm working on at the moment that I overlooked that this is going on an eGo.

^What Statistic said.