Coils internal diameters

[JayJ]

Hi all, I'm happy with the coils I build for my KFL's at around 1.4 ohm with an internal diameter of about 2.5mm but I don't always believe the saying if it isn't broke don't fix it, as improvements maybe achievable. I'm just wondering when it comes to micro coils do people find there is an optimum inner diameter with coils ?

The reason I'm asking is there are a few coiling jigs and tools hitting the market with various diameter rods. I imagine it's all down to preference, what you vape on and vaping style. If this is the case I'd like to hear the reasoning. Please keep the answers as idiot proof as possible

Jay.

[chykensa]

I use .32 Kanthal on a 3mm mandrel giving about 1.2-1.3 ohms. Works for me. Hope that helps

[jevans]

Do we have to guess how many turns chykensa ?
JayJ
I use 2mm and 0.25 Kanthal in my Protank atomisers, 2.5mm and 0.3 Kanthal in my Magmas.
According to my ohm meter, 5 turns gives me 1.4 ohms and 1 ohm respectively.
I have doubts with my ohm meter!

Jim

[JayJ]

So far then we have 2mm, 2.5mm and 3mm internal diameters. Obviously these variants will alter the amount of wicking material used. So this makes me think there may be diameters that are best suited to certain tanks or drippers.

Of course room comes into play aswell, for example if you were coiling an evod, some people still do, I did one for my daughter recently, your going to struggle using a coil with a 3mm internal diameter but on a KFL or the likes it wouldn't be an issue.

This thread might seem pointless to some as it's probably personal preference but I get these random thoughts at this hour

Jay

[jevans]

Jan 19, 2015 0:37:47 GMT JayJ said:

I get these random thoughts at this hour

You're lucky, I get them at any hour!

Jim

[VapingBad]

I settled on 3 mm with rayon wick, could be twisted 0.27 mm, single 0.32 mm or 0.40 mm use the coil calc on SteamEngine set you wire size, ohms and watts, then change the ohms until you get the heat flux in the green to find out how many wraps, if you have to go to low on the ohms reduce the wire size.

E: added screen shot watts ringed in blue, heat flux colour code ringed in red as these are the good bits that are easy to miss.

[Deleted]

I don't think there is an optimum inner diameter for coils. As you said JayJ there may not be room for a large diameter coil to fit. Also for a given wire size and ohms the diameter only effects the length of the coil, (and the amount of wicking material needed to fill it) so a small dia coil may be to long.

The method vapingbad uses is one I've adopted, it makes it easier to predict how a coil will perform.

3mm is my preference as it makes shorter coils that will fit my atties

[chykensa]

Jan 19, 2015 0:07:59 GMT jevans said:

Do we have to guess how many turns chykensa ?
JayJ
I use 2mm and 0.25 Kanthal in my Protank atomisers, 2.5mm and 0.3 Kanthal in my Magmas.
According to my ohm meter, 5 turns gives me 1.4 ohms and 1 ohm respectively.
I have doubts with my ohm meter!

Jim

Oops! That arrangement works with 6 wraps - sorry, it was late when I posted!

[chykensa]

JayJ- don't forget that the diameter also affects the resistance of your coils too. The larger the diameter, the more wire you are using, so the less wraps you will need.
Use the Steam Engine calculator and play around with different wire gauges and coil diameters to get a good idea of the differences that these parameters make.

[buggritt]

The amount of wicking material shouldn't vary at the coil. A larger diameter has more wick over a shorter distance if you use the same wire. Just the thickness of the tails will be different.
I sent for one of the new coil thingummies just for fun. Though I usually do 3mm, I've opted for 2.5.