Advice please on Coil

[bg458]

Need some advice, would the specs on this wire be ok for rebuilding a M401 atty, please and thank you.
NiChrome Wire
60% Nickel 15% Chromium 25% Iron
19 Ohms per Metre.
32wg
0.274 mm 0.0108” Diameter
If you apply 5V to a 150mm length of this wire it will draw 1.5 Amps and be hot enough to cut expanded polystyrene for modeling leaving a very smooth finish.
is very corrosion resistant and will work at up to 1100C

 

[jxmiller]

I believe so. There are people way more experienced than me so I would wait for more responses. Also, if you mull and search around you should find specifics on what people have already used to make good working atomizers. Following that route will get you what you need.

 

[roadkilldeluxe]

32ga is too thick, try 38. At 32ga, you would need to fit 7" of wire into the atty to reach 3.5 Ohms. With 38 it's more like 1 - 1.5".

 

[bg458]

does that mean if using this wire I would need to use 7 inches? I though it would be the other way around, the thinner the wire the more you needed?

 

[Jason365]

i used 36g, from Nichrome Wire
use 1 1/2 inches or less got me 3.1 ohms I think.

Good luck.

Jason

 

[roadkilldeluxe]

The thicker the wire is, the less resistance it has. Resistance is like friction that creates heat. If you push a lot of current through a tiny wire it creates a lot of heat (this is true for almost any type of wire).

If you use a super thick wire, the current can flow through it easily, but it will create little heat, and drain your battery extremely fast.

 

[bg458]

This part I understand and is logical. The part that I am having a hard time understanding (without sounding dump) is why more length would cause more heat, wouldn't the longer the wire the less the heat using the same logic as the thickness?

The thicker the wire is, the less resistance it has. Resistance is like friction that creates heat. If you push a lot of current through a tiny wire it creates a lot of heat (this is true for almost any type of wire).

If you use a super thick wire, the current can flow through it easily, but it will create little heat, and drain your battery extremely fast.

 

[roadkilldeluxe]

This part I understand and is logical. The part that I am having a hard time understanding (without sounding dump) is why more length would cause more heat, wouldn't the longer the wire the less the heat using the same logic as the thickness?

Well, Nichrome's resistance is measured in Ohms per unit length.
32ga = 11 Ohm/ft
38ga = 42 Ohm/ft

So if the wire is longer, all that "friction" and heat is stretched out even longer. Did I get your question right? I'm still waking up and am slowly getting accustomed to "thinking"..

 

[bg458]

Thanks for your help. It seems weird that a longer piece of the same metal would heat up faster than a shorter piece. So a 1 inch piece of 32ga is going to heat up less than a 7 inch piece providing the same 3.7 volt current.

Well, Nichrome's resistance is measured in Ohms per unit length.
32ga = 11 Ohm/ft
38ga = 42 Ohm/ft

So if the wire is longer, all that "friction" and heat is stretched out even longer. Did I get your question right? I'm still waking up and am slowly getting accustomed to "thinking"..

 

[roadkilldeluxe]

If I remember correctly, heat is directly related to the power (Watts) going through the wire. The power is equivalent to volts times current (V*I) or current squared times the resistance (I*I*R).

I think I may have misunderstood your question... but generally a longer piece of the same thickness wire will heat up less. I was for some reason thinking you were comparing different size Nichrome. If we assume that we are using a stock 3.7V battery, we get:

V = IR
3.7 = I * R

We can change the resistance easily by picking a specific size and length of Nichrome. So the current would be equivalent to:

I = 3.7 / R

And since power = V * I, we get the equation

P = (3.7^2) / R

Most atomizers have a R of 2.7 - 3.4. If you use a wire with a resistance of 1 Ohm, the power will be 13.7W. It will also drain your battery quickly.

So assuming I am correct in that power is directly related to heat, it doesn't matter what gage you use as long as you have the right resistance.

3.3 inches of 32ga = 3 Ohm
0.9 inches of 38ga = 3 Ohm

They might produce similar results but the lighter (smaller) wire will heat up faster.

I hope I got that right... now it's getting late here and my brain is starting to shut off...

 

[j0ker]

If I remember correctly, heat is directly related to the power (Watts) going through the wire. The power is equivalent to volts times current (V*I) or current squared times the resistance (I*I*R).

I think I may have misunderstood your question... but generally a longer piece of the same thickness wire will heat up less. I was for some reason thinking you were comparing different size Nichrome. If we assume that we are using a stock 3.7V battery, we get:

V = IR
3.7 = I * R

We can change the resistance easily by picking a specific size and length of Nichrome. So the current would be equivalent to:

I = 3.7 / R

And since power = V * I, we get the equation

P = (3.7^2) / R

Most atomizers have a R of 2.7 - 3.4. If you use a wire with a resistance of 1 Ohm, the power will be 13.7W. It will also drain your battery quickly.

So assuming I am correct in that power is directly related to heat, it doesn't matter what gage you use as long as you have the right resistance.

3.3 inches of 32ga = 3 Ohm
0.9 inches of 38ga = 3 Ohm

They might produce similar results but the lighter (smaller) wire will heat up faster.

I hope I got that right... now it's getting late here and my brain is starting to shut off...

Well said. You are exactly right.

 

[jxmiller]

From reading this the ideal wire is...


0.9 inches of 38ga = 3 Ohm

??

I was, at one point, going to try a thicker gauge wire... probably just go with this. What I am doing is modular anyways so I suppose it really does not matter as far as durability. 1 spool of 10ft 38g should last a life time. Coil gets gunked up, pop it out and put a new one in in about 2 minutes.

Hmm... what is the ideal Ohm then?

Nichrome 60
(Chromel C)
42.2 ohms/ft 38ga

Nichrome 60
(Chromel C)
27.0 ohms/ft 36ga

Nichrome 60
(Chromel C)
17.0 ohms/ft 34ga

Anyone tested longer coils of 34ga to see if it produced more vapor?..

Someone just tell me what to buy I need to get some soon. haha

 

[Jason365]

It all depends...
510's are about 2.5 on average. and get burnt tasting at 6v if you hit them to long. I am going for around 3 - 3.5 ohms at 6 volts using 36g. about 1.3 inches of nichrome with about 7 loops in the coil. I want to get some of that german "kylon" or something.. and try some of that to.

Jason

 

[j0ker]

I been considering 36 and maybe 34, just for ease of handling. I would think the 38awg would be best to keep the atty small. This is exactly why I haven't ordered....can't freaking decide where to go with it! I have a couple ideas on my pot. I saw the modular idea you posted from the german thread...Thanks. I want to go that direction as well but not exactly. I been following these threads closely. You and others a sharing some really good info, thanks!

 

[kinabaloo]

Power-in is directly related to heat. Temperature however is related to heat-in - heat-out and heat caacity; so positively correlated but not proportional.

For standard type attys (901), about 35mm of 36 swg for about 3 ohm.

34 swg might be better for alternate designs that have boosted liquid supply, but for first steps in DIY 36 swg.

Facts and figures: http://www.tji-java-ide.com/e-cigarette/index.php?option=com_content&view=article&id=175&Itemid=2

 

[jxmiller]

Did you mean "boosted power supply"? I am looking for the wire that produces the most vapor. I am not all that concerned with longevity so long as 1 month of regular to heavy use is common for the life span.

Power-in is directly related to heat. Temperature however is related to heat-in - heat-out and heat caacity; so positively correlated but not proportional.

For standard type attys (901), about 35mm of 36 swg for about 3 ohm.

34 swg might be better for alternate designs that have boosted liquid supply, but for first steps in DIY 36 swg.

Facts and figures: Technical Repository - Facts and Figures

 

[roadkilldeluxe]

Lower gauge: thicker, stronger, longer, heat slower
Higher gauge: thinner, weaker, shorter, heat faster

Higher resistance: less power, longer life, lower temps (more flavor?)
Lower resistance: more power, shorter life, higher temps (more vapor)

Everything is a tradeoff. Jacob's nichrome wire sells 10' pieces for $2-$2.50 apiece with free shipping. So for $10 shipped you could easily buy 10' each of 34,36,38,40ga.