Coil Building Questions?

[richydraper]

Right I've been building coils since the new year and I've pretty much settled on .5-.6ohm single coil, clapton, ss, builds on a TFV4. Vapes the way i want it to on my daily liquid.

One thing that seems to be eluding me after sifting through what feels like 1000s of 'how to build a coil' posts & videos is nobody appears to have done a 101 for n00bs about how different materials, different coil styles, varying wrap diameters, varying wrap counts, varying wrap spacing effects the final coil behaviour. now obviously i know that for any given material on any given coil style the wrap counts effects build resistance, but the only reason i can think that wrap diameter and coil spacing matters is for physical constraints of deck.

am i missing something or have i just answered my own question?

 

[nwhornet]

@richydraper coil diameter is, as you say, constrained by deck size but chamber size & airflow all contribute to the final outcome. A big coil in a small space chokes the airflow, whereas a 1.5mm dia coil in a big chamber will not cope with big airflow.
Again material can be subjective, ramp up time, high/low resistance, fancy coils v single coil, TC only wires.
Using Steamengine you can input various parameters such as material, diameter, wraps & see what ohm the build will be, heat flux, power etc. Very useful for getting a feel how your build will behave. Battery drain will show what amp draw a coils resistance will pull, especially useful for mech mods. As for coil size, wraps, material it becomes subjective as some people swear by claptons etc, but others only use single wire builds. RTA's & RDA's are all different, post style, airflow, chamber size etc. Worth checking any posts on how to build on the popular atties & experiment.
It's all part of the learning curve & fun of diy coil building.

 

[richydraper]

Thanks @nwhornet given me some idas for building on my other TFV8. hadnt given choking airflow any thought at all, but it make sense

 

[zouzounaki]

Diameter affects resistance as well, at a bigger diameter you are using more wire for the same amount of wraps.

 

[Tom LM]

To put it in the simplest possible way, the more wire the more resistance. So bigger diameter, more wraps, equals more resistance. The type of metal also influences resistance, kanthal being the most resistant, then nickel chrome, and stainless.
As to wire gauge, it is the other way around. The smaller the gauge the more resistant your wire will be.

 

[richydraper]

i understand that if youre wrapping at a larger diameter, then more wire will be required for any given number of wraps, upping the resistance of the build. my point was i didnt understand why different diameters would be favoured over others aside from resistance, or deck size. nw mentioned about choking a build which appears to be a bigger issue on micro/mini RBAs than full size builds. the tfv8 is a really small deck to put dual coils on, i was trying to run 2x 1.2ohm coils in her to get to my .6 'sweetspot' but i have learned that building 3mm diameter coils with 9 wraps on the only wire i have in the cupboard, was producing an incredibly soggy vape, spitting and such and just generally saturating a draw with liquid, ive since wrapped 2x .7ohm @2mm and its heading in the right direction.

TIL the number of wraps ups the surface area which produces more vapour (obviously) and i should aim more for what the device vapes like rather than trying to hit 'ideal numbers'. building at 3mm diameter on the TFV8Baby is really tight on the chimney and doesnt leave a lot of room for air flow, hence the wet draw. the 2mm sits better and doesnt saturate the draw as much, but there is still room for improvement, ill probably drop to a 1.5 and play with wrap spacing and just kinda see how 3/4/maybe 5 wraps work.