Coil ID and Taste... is Bigger Better?

[Penumbra]

I seem to want to build 3mm coils for my rta's.

Background on what I have:

2 - Subtank Mini's
- one has new dual-airflo, and the older deck, which I have filed channels a bit larger
- other is the Plus

1 - Lemo2

1 - UD Goblin Mini


The only tank thus far that Ive been able to get "great" flavor with, is the Subtank Mini's; and I've only done 3mm coils with them, and my best results so far have been with a spaced 2-wire twist of 30 AWG Kanth. Maybe like, 5-6 wraps. Also, the "pancake wicking technique" seems to also help flavor and dry hits. Ive done a Clapton (28AWG Kanth wrapped in 32 Kanth.) and twist was better. The only 2 juices Ive used for any of them are: MBV 80VG Bubble Gum (and their juice is BY FAR the thickest Ive ever used... period), and a local 50/50 Almond Pistacio Ice Cream. Both juices taste excellent, in that I can actually taste the sweetness... and not from spit-back either lol.

I have not been able to get taste even close to this with the Lemo2 or UD Gob. Mini... though these 2 tanks seem to heralded is simply fantastic!!??

Obviously, with the Gob Mini, 3mm is barely feasible, and in practical terms not really.

My assumption when choosing 3mm coils is that the "bigger the better"... in terms of the ability to then have a thicker wick, and thus further avoid dry hits (which is something that I cant seem to easily avoid, though I can with my subtank). I also, for whatever reason, somehow feel I might get better taste from the larger ID. Is this a correct assumption?

Should I still be able to get the same level of taste/wicking with smaller inner dia. coils?

 

[Boden]

I make sure the coil is smaller than the air flow port pointing at it. If you go larger than that port the top of the coil/wick will overheat giving a funky taste.

 

[Penumbra]

when you say airflo port "pointing" at it... do you mean the main whole on the deck? and not the various holes on the airflo adjustment component?

Also, you say the coils "size" needs to be smaller... how is this size measured? are referring to volume, length, width, etc?

 

[Boden]

when you say airflo port "pointing" at it... do you mean the main whole on the deck? and not the various holes on the airflo adjustment component?

Yes, the hole in the build deck.

Also, you say the coils "size" needs to be smaller... how is this size measured? are referring to volume, length, width, etc?

I keep the OD of the coil smaller than the deck air hole. The width can be a bit larger but not much.

This diagram is for something different but it demonstrates the basic idea.

If the size of the air port decreases in relation to the cylinder that the air has to go around you get a dead zone behind the cylinder. In this dead zone the coil is not being cooled by the incoming air and will overheat.

 

[Penumbra]

wow man!!! dead-zones huh?

very interesting... Im thinking, despite getting what I consider great flavor on my subtank mini, its all up to build/wicking for flavor. In other words, I must have "cracked the code" on my subtank mini, but have not cracked the codes on my ud gob-mini and lemo2.

 

[Penumbra]

perhaps I also should clean them better. All i did was run the hottest water my hands could take over the disassembled components. I left deck screws in... AND on the lemo2, the bottom portion (where airflo control is) can some how be disassembled but I cant quite get it apart.

What / how do you recommend proper, 100% thorough cleaning of machine oil?

 

[Boden]

wow man!!! dead-zones huh?

very interesting... Im thinking, despite getting what I consider great flavor on my subtank mini, its all up to build/wicking for flavor. In other words, I must have "cracked the code" on my subtank mini, but have not cracked the codes on my ud gob-mini and lemo2.

Yeah, you have to try different things in different tanks to find what works best for you and the Eliquid you are using.

perhaps I also should clean them better. All i did was run the hottest water my hands could take over the disassembled components. I left deck screws in... AND on the lemo2, the bottom portion (where airflo control is) can some how be disassembled but I cant quite get it apart.

What / how do you recommend proper, 100% thorough cleaning of machine oil?

I happen to have a metal lathe/mill. First remove the O-rings and wash them with dish soap, then rinse really well. For the metal parts, I soak the parts in Windex then wash in soapy water (dawn dish washing soap) then rinse well with running water.

 

[Penumbra]

big thanks mate!!

 

[Cullin Kin]

I wrap all of my coils at 3mm (perfect on the Lemo 2). I've worked my way up from 1.5mm back when I started rebuilding about two years ago.

About two weeks ago I built a set of 3.5mm ID coils, then a set of 4mm ID coils. They didn't perform nearly as well. Plus they use much more wick and I notice the wick getting 'clogged' much more easily.

There's this dude on a FB group I'm on, he builds coils on a 7.4mm mandrel... Nope.

 

[Penumbra]

what kind of coils?.. i.e. #of wraps, gauge, spaced or contact?

I just finished trying the lemo2 yet again.

I twisted 2-strands of 28 gauge kanth.
I wrapped 4-5 wraps, spaced approx. 1mm apart on a 3mm bit; however, the springiness of the twisted wire caused that 3mm wrapped ID to expand a bit... came out to 0.9 ohms.

I wicked w/ my usual, KGD, and tried my 80vg Mt Baker Vapor Bubble Gum.

I tried 20 to 21 Watts so far, with AFC fully open, down to about 1/4 open, and flavor is NOT satisfying.

Does machine oil have a sourish taste?

I rushed things tonight, and only disassembled it and ran each component under hot-as5 water.

I cant ever serm to disassemble the air flow control ring from the absolute base component (the one that the deck is attached to). I know theres an o-ring up in there... maybe thats all that still needs to be cleaned; but with my luck, cleaning any of this most likely will not help... I know how "this" goes... (facepalm).

 

[CasketWeaver]

On average my coils are built at the 2mm ID or 1/8 ID. Why? For the sake of sanity of course. Will / would a 3mm ID have much of an impact? I don't know. But referring to other posts I've posted in - have you tried vertical coils yet?

 

[Penumbra]

On average my coils are built at the 2mm ID or 1/8 ID. Why? For the sake of sanity of course. Will / would a 3mm ID have much of an impact? I don't know. But referring to other posts I've posted in - have you tried vertical coils yet?

not yet no...

I figure, these regular horizontals should be able to at least work... if this tank is as sweet as its heralded as being.

 

[TheotherSteveS]

Yes, the hole in the build deck.



I keep the OD of the coil smaller than the deck air hole. The width can be a bit larger but not much.

This diagram is for something different but it demonstrates the basic idea.

If the size of the air port decreases in relation to the cylinder that the air has to go around you get a dead zone behind the cylinder. In this dead zone the coil is not being cooled by the incoming air and will overheat.

lol...so we should be vaping at Reynolds numbers greater than 10000000.....

Need to remember here that a lot of this will depend on things like the velocity of the airflow, volume of airflow, volume of vapour created, coil type (spaced/non-spaced which will offer different frictional resistance) etc etc..tis really interetsting though!!

 

[93gc40]

fwiw.. Do not assume that the perfect build for one atty will ever work in any other atty.


Using a Kayfun, single coil air below coil.
I find a coil placed closer to the air inlet hole make batter flavor than one place away from it.. Coil ID at least for me, just affects wicking. Too small I get a dry hit too big I get gurgling. I find spaced coils make better flavor than contact. Spaced coils also gunk-up slower. (I use NETs) I also build tensioned coils.. (homemade "Artistic Coil gizmo" with 14" pipe wrench as a weight)

 

[DaveP]

I've been winding 28ga 3mm coils forever and lately I've been thinking about going to 2mm just to get more wire in contact with the wick. Same wire length, just more turns of smaller diameter should atomize more juice. That might mean that I turn down the voltage to get back to my former vapor level. Colder vapes are usually less flavorful, though. I'll have to try it to see what happens.

 

[GeorgeS]

While I'd think that any authentic Lemo2 (or other brand RTA) would not have machine oil in it when you get it out of the box.... I suppose if some clones have oil some authentic ones might also.

I've wondered about coil size - ID, Wraps - target resistance - much smaller than 2.5mm is difficult to wick, I tend to use 3mm and sometimes use 3.5mm.

IMHO the challenge here is to fit the coil between the contact screws. The Lemo2 has holes which allow make it easier to fit a coil that is longer than the distance between holes.

Personally I've considered doing a vertical coil. I don't think the STM has room for it however I also think the Lemo2 does.

 

[93gc40]

I've been winding 28ga 3mm coils forever and lately I've been thinking about going to 2mm just to get more wire in contact with the wick. Same wire length, just more turns of smaller diameter should atomize more juice. That might mean that I turn down the voltage to get back to my former vapor level. Colder vapes are usually less flavorful, though. I'll have to try it to see what happens.

If all you are changing is the ID of the coil the "coil" temp and surface area will be the same. Now the cooling you get from the juice will be reduced with a smaller ID. Small id = less wick = less juice = more heat transfer potential

 

[DaveP]

I vape Kayfuns, the 3 and the 4. There's lots of room in the chimney for coil width, both vertical and horizontal. I just wonder how wide a horizontal coil can be and still efficiently use the vapor coming off the coil. I guess if vapor is created in the chamber it goes up the chimney. Still, air mix makes a difference in the way it's stimulating the coil to produce, I guess.

 

[Boden]

Does machine oil have a sourish taste?

Yes

 

[Boden]

lol...so we should be vaping at Reynolds numbers greater than 10000000.....

Need to remember here that a lot of this will depend on things like the velocity of the airflow, volume of airflow, volume of vapour created, coil type (spaced/non-spaced which will offer different frictional resistance) etc etc..tis really interetsting though!!

I Vape at Re=<1 personally

It's the first graphic I found that showed the basic idea.

I accidentally put a 3.5mm ID coil in my Russian 91 the other night and it tasted awful, it was for my STM. The bottom of the coil was fine but the top was sealed in a layer of burnt eliquid.