Coil Building: Help Needed.

[keDa]

Hi! I'm trying to build a dual coil for Moonshot rta.
I will use Kanthal 0.25mm (30 AWG) wire.
I'm using this website to understand how to do it. (steam-engine[dot]org)

So the questions are:
1) Does all rta, RDTA, rda need a specific wire or all the wires work?
2) What does the number of wire wraps change?
3) What is your favorite ohm resistance on Kanthal 0.25mm (30 AWG) wires?
4) Should build bigger inner diameter of coil if I want lower resistance?

P.S. First time coi builder.
Extra tips will be appreciated.
Thanks.

 

[thomas l]

i don't have a moonshot but in general, any wire size will work as long as it fits,wraps change resistance, i don't use 30 ga lot of 26 ga and 24 ga
should be able change it in steam engine , wraps,size,wire type etc.

 

[Paul lamb]

1) it is the same principle for all rebuildables
2) number and size or wraps effects how high the resistance will be
3) personal preference IE I like 22g lots of wraps for surface area
4) bigger coils equal higher resistance

Play with steam engine it's your friend

 

[keDa]

Wow, thanks for the quick answer. If I choose in steam-engine target resistance 0,7ohm, in the results it shows me resistance per coil 1.4ohm. Does this mean that I have 0.7 resistance or 1.4?

 

[ibndevilish]

you have to build both coils at 1.4 then you will have aprox of what you want which is 0.7

 

[Bunnykiller]

the thinner the wire ( higher the AWG#) the resistance goes up per inch of length
the longer the wire, resistance increases...

goto this link and see if you can use this excel sheet for coil making

Excel Coil Calculator

 

[IMFire3605]

Wow, thanks for the quick answer. If I choose in steam-engine target resistance 0,7ohm, in the results it shows me resistance per coil 1.4ohm. Does this mean that I have 0.7 resistance or 1.4?

Simple principle of electricity, each time you add a parallel path in an an electrical circuit, you decrease the resistance. So here each parallel wire splits the resistance by that number, Resistance of each Coil/Number of wires=final resistance. So steam engine says 1.4ohms per coil, we have two wires (in parallel), 1.4ohm per coil/2=0.7ohms. It gets a little more advanced after that, but if each wound coil is on separate wires, it is parallel (divides resistance), if on the same wire, called a series (multiplies the resistance). Another principle, thinner the wire you use, higher the resistance (example 32awg wire will have high resistance, analogy single lane road), while thicker wire will have lower resistance (example 22awg wire will have lower resistance than 32awg, analogy a 4lane highway). More wire used per coil will increase in resistance, this is affected by the Inner Diameter (ID) being used, and number of wraps in the coil, you are taking 3 to 6 inches of wire and compacting it into a manageable and usable structure to fit into a restricted space and making it effective to heat and vaporize liquid in the wick you place into it compared to laying it straight.

 

[Two_Bears]

Hi! I'm trying to build a dual coil for Moonshot RTA.
I will use Kanthal 0.25mm (30 AWG) wire.
I'm using this website to understand how to do it. (steam-engine[dot]org)

So the questions are:
1) Does all RTA, RDTA, RDA need a specific wire or all the wires work?
2) What does the number of wire wraps change?
3) What is your favorite ohm resistance on Kanthal 0.25mm (30 AWG) wires?
4) Should build bigger inner diameter of coil if I want lower resistance?

P.S. First time coi builder.
Extra tips will be appreciated.
Thanks.

Resistance is determined by the length of the wire in the coil.

Most wire will say x.xx ohm FT

The resistance in 1 foot of wire.

 

[DingerCPA]

Hello @keDa! To be quite honest, if you're just now getting into building coils, practice a bit building a single coil until you get comfortable. SteamEngine has great guidelines, but one thing I've learned from that site is that LEG LENGTH can play into your build (which I often would neglect until a helpful soul pointed it out to me one day.)

Parallel resistance (two coils) is calculated as 1/(1/R1 + 1/R2), where R1 and R2 are the coils' resistances. When building dual coils, you have to be pretty precise that you have "balanced" coils so that you don't overdrive one side versus the other. A 1Ω and a 2Ω coil would net you a 0.75Ω parallel build, but twice as much current is going to flow through the 1Ω coil and not heat the entire build evenly.

Some other points of thought, a bigger diameter build of the same wire type and number of wraps will yield a higher resistance because there is more material there (plays into the resistance/unit of length) - bigger diameter needs more length of wire for same number of wraps.

 

[rice721]

A lot of good info.

Basically your resistance depends on 2 things, distance (wire length: i.e. How many wraps and inner diameter) and thickness (wire gauge).

 

[keDa]

Hi again. Quick question:
I tried to build a dual coil from Kanthal 22AWG (0.65mm).
-10 wraps with 4.0mm inner diameter;
-7 wraps with 3.5mm inner diameter;
Both of them were with 0.3 ohm resistance, but I tried to get 1.0 ohm resistance.
Looks like I cant get over 0.3 ohm, why? What am I doing wrong?

Maybe you could tell me your favorite build so I can try it out?
Thanks again.

 

[rice721]

Hi again. Quick question:
I tried to build a dual coil from Kanthal 22AWG (0.65mm).
-10 wraps with 4.0mm inner diameter;
-7 wraps with 3.5mm inner diameter;
Both of them were with 0.3 ohm resistance, but I tried to get 1.0 ohm resistance.
Looks like I cant get over 0.3 ohm, why? What am I doing wrong?

Maybe you could tell me your favorite build so I can try it out?
Thanks again.

I prefer to use 24gauge or 26 gauge kanthals. I tend to build around 0.35~0.8 if I am subohming and doing direct lung hits or 1.2~1.4 if I'm doing mouth to lung with 28gauge kanthal.

[edit] you shouldn't be getting 0.3ohms with 7wrap 3.5mm iad.

Also with 22g its almost impossible to get 1ohm in dual coil or even single coil setup. You need ALOT of wraps.

 

[ElConquistador]

I would perfect a single coil build before tackling duals. Weird that you get the same reading at 7 and 10 wraps!

 

[evan le'garde]

It's funny coil building !. I started coil building when i used to use Kanger T3's. I'd just copy whatever coil was already in it. Did the same when i started using the Kanger Protanks. After building coils in those devices for what seemed forever, with the thinnest wire i might add, 32awg, i got seriously good at it.

I have had conversations with various members about how they can't deal with thin wire like 32awg. Whereas i have been building with it for such a long time it only takes me about 5 minutes to rewire my Kayfun.

When i started using dual coil RTA's i realised i was going to need thicker wire if i wanted bigger clouds. So 26 or 25, 24awg in an RTA with maybe half a dozen wraps and an inner diameter of 2.5mm were the types i was experimenting with. Usually the main problem i'd come across would be getting these coils to fit inside. With the RTA's i have and building coils with inner diameters of 2.5 my go to wire is 25awg. Both coils have to be identical in size/wraps.

 

[evan le'garde]

But you have a target resistance of 0.7ohm.

If you have to use 30g wire then for a start both coils have to be identical. The inner diameters should be 2.5mm. The number of wraps should be 5 per coil. Each coil will have a resistance of 1.4ohm. Two coils, each with a resistance of 1.4ohm, will have a combined ohm'age of 0.7ohm.