# Coil Calculator



## Tom (16/1/14)

this is a coil calculator, in german tho...but you won't need a translator for it (hopefully)

http://www.hundacker.com/dampfspulen-rechner/


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## Gazzacpt (16/1/14)

Thanks for the link @Tom

Its pretty accurate. Just need to drop a coil to make up for the tails or legs as some refer to them. Length is about spot on just tested it.

Reactions: Like 1


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## Tom (16/1/14)

Innendurchmesser Wicklung - inner diameter coil
Laenge Draht - wire length
Anzahl Wicklungen - wraps needed


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## CraftyZA (17/1/14)

Very neat, and thanks for the share!
Just remember to double the wraps and length if you do double coils


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## Silver (17/1/14)

Thanks @Tom - that's super. 

Am just curious if I understand this correctly. Not a coil builder yet 

- I picked *Kanthal A-1 0.28* - Incidentally, is this Kanthal 28 gauge or is it 0.28mm diameter wire?
- I picked *1.1 ohm *resistance
- I picked diameter of *1.5mm
*
It said the length is 47mm and the wraps is 9.

So just a question, if its 9 wraps around 1.5mm, that's about 13.5mm. That's nowhere near the total length of 47mm. Am I missing something? Or does this mean the two end pieces make up the difference?. About 33mm difference or 16mm for each end piece that gets fastened into each screw.


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## 1am7h30n3 (17/1/14)

@Silver1 the coil length should be calculated as follows:
(number of wraps * coil circumference) + tails
circumference = 2*pi*r
if you wrap around a 1.5mm drill bit then your inner diameter of coil is 1.5mm, giving a radius r = 1.5/2 = 0.75mm.
length = (9wraps * 2*pi*(0.75mm)) + tails = 42mm + tails
This gives 5mm spare for tails or 2.5mm per side (and remember the length of tails is only the length from coil to screw, not the length you wrap around the screw etc.
Hope this helps!

Reactions: Like 1


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## Silver (17/1/14)

Thanks @1am7h30n3 - totally daft of me to forget we're wrapping something around a circle 
Embarrassed 
Thanks for clearing it up.

- area of a circle is Pi*Rsquared and *circumference is 2*Pi*R*
- duh, how could I forget that.

- I can think of another benefit of vaping... which I am going to go now and add to the 100 Benefit list....


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## vaalboy (27/2/14)

Quick question........

If you consistently use kanthan 28 gauge will every coil with the same diameter and wraps equate to the same ohms or should I rather test every coil I make?

Afterthought, are ohm readers available in SA or should I just use a multimeter?


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## BhavZ (27/2/14)

vaalboy said:


> Quick question........
> 
> If you consistently use kanthan 28 gauge will every coil with the same diameter and wraps equate to the same ohms or should I rather test every coil I make?
> 
> Afterthought, are ohm readers available in SA or should I just use a multimeter?



Do you mean something like this: http://vapemob.co.za/product/ohm-meter/


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## Silver (27/2/14)

Hi @vaalboy 

Not sure about how consistent the coils are with the same specs. I havent built enough 
My guess would be that they would be very similar unless the wire was not consistent.

As for an ohm reader. You can use the ones on most electronic mods. I got the Sigelei dedicated ohm reader from SkyBlue. @Matthee advised me a while back and I listened to him  It does make for a great base to work on when you build coils on a rebuildable.

Reactions: Like 1


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## Andre (27/2/14)

vaalboy said:


> Quick question........
> 
> If you consistently use kanthan 28 gauge will every coil with the same diameter and wraps equate to the same ohms or should I rather test every coil I make?
> 
> Afterthought, are ohm readers available in SA or should I just use a multimeter?


Yes, they should come out more or less the same, but you also use the ohm meter to check for shorts. You should check for shorts without and with the cap on your atomizer. Also after squeezing your coil, the resistance will change a bit. Skyblue had ohm meters, which is great as a working surface, but a multimeter is fine or just use your SVD (think you have one). Another tip, if I may, when re-wicking always check your post screws - they come loose, especially with 28g.

Reactions: Like 1 | Agree 1 | Informative 1


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## Riaz (27/2/14)

@vaalboy to be safe, rather test each coil that you make.

Reactions: Agree 1


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## vaalboy (27/2/14)

You guys are awesome. Thanks for the advice.

Reactions: Like 1


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## ET (27/2/14)

nice find tom, this is awesome. still waiting on my ohm reader but this will be a great guidepost


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## Tornalca (27/2/14)

If you are using android you can also install this app. Vaper's Toolbox. Great app.

@RevnLucky7 posted it a while back, giving him the credit!
http://www.ecigssa.co.za/index.php?threads/android-app-for-coil-builders.630/

Reactions: Like 1


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## Tom (30/4/14)

posted screenshots in the vape mail thread now...maybe this one needs resurrection


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