Trying to make the perfect Micro Coil.

[LEDBETTER122]

Im wanting to make a 1.8 Ohm micro coil, I have ordered some 28ga kanthal wire and it should be coming in by next week.

Now im trying to get the correct calculations, so when I get it in I know exactly how many wraps I need to reach my 1.8 Ohm goal.

I might be wrong but here are my calculations, I have a pin that is 1.30mm in Diameter (that im using to wrap the coil).

Ok so the circumfrance is Pi * 2 * Diameter which is 0.65 (1.30/2), so the circumfrance of the pin I am using is 4.082 mm

The 28ga kanthal is 5.27Ohm per/ft so I do 5.27/12 (inches in a foot) which is .44 ohm per inch (.439 actual number) and so I take my GOAL 1.8ohm and divide that by .44 (1.8/.44) which is 4.10 (4.09 actual number).

So I need 4.10 inches for 1.8ohm worth of wire, so I convert the 4.10 inches into Milimeters which is 104.14mm (25.4mm in a inch, so 25.4*4.10) then take 104.14 and divide it by my circumfrance of my pin im wrapping it on which is 25 wraps.

Now im thinking either my math is wrong, because I think 25 wraps might be to many, or I need to up the size of the pin I'm going to be wrapping it on.

Any suggestions (BTW I dont have a 1/16 drill bit)

 

[KurrptSenate]

What are you putting the coil in?

My favorite micro coils are wrapped around a 5/64ths drill bit, slightly bigger than a 1/16. For a 1.8 ohm coil, that's about 11-12 wraps.

What device will you be firing your coil with?

 

[LEDBETTER122]

I have a kanger mini protank 2 with just an ego twist battery

 

[KurrptSenate]

if you a coiling a protank head, you might want thinner wire for higher resistance. 28 gauge is quite a few laps that you might have a hard time putting into a head. it can be done, but like I said, you'd probably have a much easier time with 30 gauge, or even 32.

 

[LEDBETTER122]

See I assembled a 32ga micro coil at about 2.2 ohm (about 9 wraps around a Thumb tack) and the coil its self is not quite wide enough.

I'm pretty good at doing tedious work with small objects (No pun Intended)

 

[KurrptSenate]

As long as you have patience and realize you're going to mess some up from time to time, its no biggy.

I assume you had problems wicking the thing. I wrap my PT2 coils around a syringe tip for an e juice bottle. I've gotten used to it (wicking)

it can definitely be done. you could try that wire around your 1/16ths at like 4 to 6 wraps. that would probably work

 

[LEDBETTER122]

Ok I did the calculations for a 5/64 drill bit which is 1.98 in diameter and the radius is .99 and the circumfrance is 9.76

So I take 104.14 mm (which is 1.8 ohm) and divide that by 9.76 which is 10.67 wraps for 1.8mm (not including wire to assemble)

Idk I got a pair of calipers and im going to go around measuring pins and nail-like things until I get the perfect pin for the perfect amount of wraps to make the perfect length for the Mini protank at 1.8 ohm

 

[KurrptSenate]

it will definitely improve the taste and vapor on the protank. I don't use mine anymore.

 

[LEDBETTER122]

Nevermind I had my math wrong, for the 1.30mm pin its 16 wraps for 1.8 not 25, so think maybe that the 1.30mm pin will work fine.


I'm just a perfectionist and I need to make this as best as human possible with an ego twist stick battery lol

I think i did 3.14*2*(radius), instead the formula for circumfrance is 3.14*3.14*(Radius)

 

[umanbean]

If you hit the "perfect Micro Coil" on the first try by doing the math, you're a better man than I.

I used the ol' trial and error method, trying various wraps with 32g, 31g, finally 30g... and measured resistance of my first attempts with a digital multimeter at first, later picked up a Vamo then an iTaste VV3... both of which have ohms readouts. For PT2/Evod coils, I've settled on:

30g Kanthal
1/16 drill bit (0.0625" or ~1.6mm)
8 close wraps
= ~1.8 ohms (+/- 0.1)

If I'm feeling really steady-handed that day, I'll thread some cotton thru... otherwise "untwist" some Peaches & Cream Ecru yarn and fish two strands through with a folded-over piece of Kanthal, making four strands thru the coil. Two strands on top for a "flavor" wick, and 50/50 juice works just right. Good Luck.

 

[danny4x4]

You're not going to be able to fit 16 wraps of 28awg into the protank. 12 wraps is already a tight fit.

 

[LEDBETTER122]

I will post a picture of It, I also do alot of trial and error, I was just doing the math to get a round about of wraps I need.

I found a shop that just opened up actually sells kanthal wire (The other vape shops don't, weird huh) so im going to run by there and grab me some wire after work to give this a try

 

[LEDBETTER122]

@danny

is 12 wraps a tight fit?

See I dont know for sure since I have not performed the coil yet, I just yesterday figured out how to make micro coils.

 

[LEDBETTER122]

Alright I didn't think about 28 being thicker than 32. Which I should have know since I'm an engineer and have to deal with wires and electronics all the time.

So 12 wraps probably is a tight fit

 

[KurrptSenate]

yea, like I said, you probably wouldn't want more than 8 wraps in a protank

 

[danny4x4]

I haven't done 28awg in a protank for a while, but if I remember correctly, 12 was what I was comfortable with. You might squeeze in another wrap, BUT the coil will be too close to the walls. You DEFINITELY DON'T want the coil touching the wall.

That said, imho, 28awg in a protank takes too long to heat up to optimum temperature for my liking. I prefer 30awg in a protank. But that's just my preference. 8 wraps of 30awg on a screwdriver that is close to a 1/16 bit in size, nets me 1.6 ohms to 1.8 ohms.

 

[Leothwyn]

I've settled on the same thing as umanbean and danny. 8 wraps of 30g works out great in my mini PT2 on my Spinner.

 

[Kemosabe]

i wasnt able to use a larger than a 1/16" mold when recoiling my T3 and evod/pt heads. and even the 1/16" barely fit through the slots- its was a wedge of a fit. so, what youll likely want is thinner wire than 28g. 30g is likely as thick as you can go. and youd likely have a much easier time using 31 or 32g.

also, youll want to factor in your leg lengths into your total figure. the distance between the coil and the rubber stopper used to capture the legs will have to be factored into your total wire length. unless youre using nr-r-nr wire joins.

 

[LEDBETTER122]

Ok so I got a question, so will 28ga at 1.8 ohms fire up the same as 32 ga at 1.8ohm?

 

[Ryedan]

Nevermind I had my math wrong, for the 1.30mm pin its 16 wraps for 1.8 not 25, so think maybe that the 1.30mm pin will work fine.


I'm just a perfectionist and I need to make this as best as human possible with an ego twist stick battery lol

I think i did 3.14*2*(radius), instead the formula for circumfrance is 3.14*3.14*(Radius)

LEDBETTER, the formula for circumference is 'pi * Dia'. That's the same as '2 * pi * R'.

Also, I think it would be more accurate if you add once the diameter of the wire to the diameter of the I.D. of the coil for your calcs. So, wrap on a 0.0625" (1/16") pin with 0.010" dia wire, the diameter I would use to calculate with is 0.0725".