Low resistance wire?

[Dan]

Hey everyone

Just a quickie..

Can someone advise me as to what diameter resistance wire I should look at buying to achieve a 1.2ohm wrap with 4-5 coils?

I'm currently using 0.20 kanthal A1 and the evic is reading 1.2ohms with 2 (yes, just two!) wraps and 1.5 ohms with 4 wraps..

Here's what I want to achieve..

Firstly, This low resistance malarky is bloody wonderful!! (50/50 GVC, 1.2 ohm head, 9.5w Evic, RSST with 1.5mm airhole, 2mm rope and mesh skirt wick... awesome!!)

I would like to have more wraps around the wick to see how it affects things.. Am I right in thinking that more wraps will give more throat hit and fuller flavour??

I would also like to have a go at building some 0.6-1ohm coils for my drawtube to see what the fuss is all about with sub ohm coils.. This is nigh on impossible with 0.20 A1!!

What would you guys advise?

Which wire should I be looking at??

I'm going to keep the 0.20 for my evods but the rssts are crying for something a bit more special! Tease-smiley

[DiscoDes]

You could use .22 but as you use thicker you have to wait longer for the coil to get up to temp, so pressing before you pull works best.

[Dan]

Hi DiscoDes

I can set the Evic to RVW so it ramps from 11w to 9.5w over a few seconds and then stays at 9.5w for the duration..

Just a case of will this work for the thicker wire..?

[DiscoDes]

Jun 24, 2013 12:02:30 GMT Dan said:

Hi DiscoDes

I can set the Evic to RVW so it ramps from 11w to 9.5w over a few seconds and then stays at 9.5w for the duration..

Just a case of will this work for the thicker wire..?

Generally the thicker the wire the lower the resistance, but longer heat up time.
Also keeping the legs as short as possible to reduce resistance or making the legs from no resistance wire helps.

I don't know how low resistance coils the Evic will run though?

[markm]

.5 x .1 ribbon wire is a great compromise - it heats up faster than round section wires
has low resistance and a larger surface area.

[izan]

Twist the .20
Watch here for the general idea.


Have fun
I

[Dan]

Jun 24, 2013 12:12:17 GMT DiscoDes said:

Jun 24, 2013 12:02:30 GMT Dan said:

Hi DiscoDes

I can set the Evic to RVW so it ramps from 11w to 9.5w over a few seconds and then stays at 9.5w for the duration..

Just a case of will this work for the thicker wire..?

Generally the thicker the wire the lower the resistance, but longer heat up time.
Also keeping the legs as short as possible to reduce resistance or making the legs from no resistance wire helps.

I don't know how low resistance coils the Evic will run though?

Sounds logical.

Well the positive leg can be kept short as the wick can be pulled quite close to the centre post.. negative leg could benefit from no resistance wire but I have absolutely no idea how this all works! Distance from negative post to coil is about 8mm.. 

Well.. I was led to believe that the Evic will only run 1.4?+ coils, but the fact that it's been happily running a 1.2? head for early 3 days without any codes would dispute that fact!!

From what I've read (chart below), 32awg/0.20 A1 gives 1.2? of resistance per inch... 31awg/0.22 A1 gives 0.9?/inch...

So by my working out I'm using ~1.25" for the 1.5? coil which is 4 wraps..

So.. 4 wraps of 0.22/31awg would give a 1.125? resistance.. Too low for the Evic, and too high for the drawtube..

So if I'm thinking straight, (bear with me!!) assuming that each extra wrap is an extra 0.15? of resistance, (0.20mm A1 2 wraps = 1.2?, 4 wraps = 1.5?)

and assuming that the 0.22 gives the same variance as the length increases as the 0.20, 5 wraps of 0.22/31awg would give 1.275? total resistance which would suit my Evic perfectly..

And the for the drawtube, I could do a 3 wrap with 0.22 which in theory would give me ~0.975? and 2 wraps ~0.825?

Here's a little chart I've come across with all of the relevant information which has given me these figures;

30 awg (?/in) 0.7 ohms
31 awg (?/in) 0.9 ohms
32 awg (?/in) 1.2 ohms
33 awg (?/in) 1.4 ohms
34 awg (?/in) 1.8 ohms
35 awg (?/in) 2.3 ohms
36 awg (?/in) 2.9 ohms

So in theory (starting to like that word LOL), the 0.22/31awg would be perfect for a 1.2-1.3? 5 wrap coil for the evic, but I would need to step down to the 0.25 30awg to get a sub ohm coil for the drawtube if I want to have more than 2-3 wraps... (4 wrap of 30awg would give ~0.875?)

Can someone confirm the figures above are correct please? My head hurts! lol

[Dan]

Jun 24, 2013 12:19:48 GMT markm said:

.5 x .1 ribbon wire is a great compromise - it heats up faster than round section wires
has low resistance and a larger surface area.

Hi markm

I've been trying to use the 0.3*0.1 ribbon I have to give more contact with the wick but I just cannot get it working right... Evic keeps coming up with a short.. replace the ribbon with A1 0.20 and it works perfect! 

Made sure nothing is touching, and that the coils are spaced evenly, but it just does not want to work!!

[Dan]

Jun 24, 2013 12:55:13 GMT izan said:

Twist the .20
Watch here for the general idea.


Have fun
I

Oooohhh, I did hear about twisting the wire a while ago, but was too much of a noob to take much notice.

Will have a watch!!!

Thankyou izan

[markm]

Ribbon wire is no different from wrapping other than it is more important to keep the wire nice and flat,
the sharp edges could dig in if it was twisted. I run it over my thumbnail, squeezing it against my forefinger
it takes out any kinks but will make it curly - if you anneal it (run over it with a lighter) you can take the spring
out of the loops which makes it easier to wrap (but also easier to put a kink back in it) so I don't bother.

[markm]

Twisted will halve the resistance - you can also fit dual coil to a single wick - which will also halve
the resistance but it a bit fiddly to do.

[Dan]

Jun 24, 2013 13:23:47 GMT markm said:

Ribbon wire is no different from wrapping other than it is more important to keep the wire nice and flat,
the sharp edges could dig in if it was twisted. I run it over my thumbnail, squeezing it against my forefinger
it takes out any kinks but will make it curly - if you anneal it (run over it with a lighter) you can take the spring
out of the loops which makes it easier to wrap (but also easier to put a kink back in it) so I don't bother.

I think this may be the problem..

The wire I'm using came from the wire mesh company on a tiny little spool..

It sprang off a while ago and it is now full of kinks.. pretty much decided that I'm going to strip off whats damaged and bin it as it's pretty much unusable now..

Was lovely to use on the EvoDs before it kinked up though.. so easy to wrap!!

[Dan]

Jun 24, 2013 13:25:39 GMT markm said:

Twisted will halve the resistance - you can also fit dual coil to a single wick - which will also halve
the resistance but it a bit fiddly to do.

So if I were to twist the 0.20 I have, and wrap it 4 times around the wick it should give around 0.75 ohms?

Maybe I should try that for the drawtube... Anything to be wary of before I try it?

Will obviously check it with the multimeter before trying it, but what are the "danger points" of twisted wires? If any?

Don't think it would be plausible to get a 1.2ohm head on the evic without having a serious amount of coils (12 wraps!) So will still need to order some wire...

[markm]

You can fix even badly crumpled wire by drawing it out over your nail, just untwist any tight loops first.

[markm]

Twisted is just stiffer, so be carful not to pinch your wick, also the rough surface
is possibly slightly harder to work out any hot spots.