Micro coil

[edyle]

Will definitely try to get an ohm meter.

The coil will have to be set into the protank before I can measure the ohm am I right?

No you can use your multimeter to measure anytime, but definitely also measure it after hooking it up;

For a protank, it is better to use prewelded NR-R-NR than to use plain R (resistive) wire, because the connections are on the rubber/plastic/silicone grommet at the base of the atomizer, and that resistive wire will get hot.

With a rebuildable (rba) the wire will connect on metal screw, so its not a big problem to use all resistive wire;

 

[Nataani]

Ummm ok. Lots of screaming about safety - all true.

However, you do not need an "ohm checker", better known as a resistance meter. Your Vamo has a resistance meter built in, which is far more accurate than the little black box things, which I have personally have seen have an error of up to 0.2! Hold down the right button for a few seconds and the resistance will show on the screen. With a Vamo v5 it simply will not fire if you have a short or a coil of too low resistance. For the purpose of building protank coils, the Vamo is a perfectly fine meter to use, if you get into serious sub ohm building, you may consider getting a high quality meter.

In a protank I wouldn't recommend such a small internal diameter, but each to their own. A 1mm internal diameter needs, as someone else said, a 7/6 wrap to achieve 1.8 ohms with 32 gauge wire when wrapped as a micro coil (contact coil). The lower the gauge of the wire, the thicker it is, and the lower the resistance. Keep in mind when buying wire that this relationship is not linear, by which I mean that the resistance does not change by the same amount each time you step down the gauge.

Example:
28 gauge - 0.44 ohms/inch
30 gauge - 0.70 ohms/inch - (0.26 difference from 28 gauge)
32 gauge - 1.09 ohms/inch - (0.39 difference from 30 gauge)

So as you go down in gauge the resistance of your wire decreases at an decreasing rate.

My personal prefered build for the protank at the moment is:
3/64th drill bit
8/7 wrap contact coil
30 gauge wire
1 strand of peaches n cream ekru cotton yarn through the center (sold at walmart for $1.50)

 

[unrl]

Get an Ohm meter and measure what length of the wire gives you 2 ohm; that is the LENGTH to use; it is not the number of wraps that matter, it is the LENGTH.

Remember to check the meter for zero offset

Good info mate. Oh yeah thinking about it is the length that'll matter. So I would have to try wrapping it (for example to get an approximate length), put it through the base of the protank and then use the ohm meter to check.

I know nothing about building E-Cig coils, but I do know about resistance wire.

It'll have a very linear resistance per foot measurement.. You can check it with a multimeter (Or if it's spec'ed, just look at that) and divide from there to get the length you need.

If you're wrapping a coil, a small, coarse thread screw might help.. Maybe wrap it around that?

Will be using a screw if all else fails Not sure what equation to use to divide? Do you mean that meter can actually measure resistance without me having to go through the hassle of coiling then putting into the base before measuring?

No, you are wrong. 28 guage is thicker. the thicker the wire the less resistance the lower the ohm, depending on the wrap. 32 guage is a nice guage to learn to wick coils. Since you got that you should be in good shape. harbor freight ohm meter get one they are only 5 bucks

 

[Jh_X]

Do you mean that meter can actually measure resistance without me having to go through the hassle of coiling then putting into the base before measuring?

Oh yeah.. Yeah, any digital multimeter (doesn't have to be real expensive) and either measure off a foot of wire, set the meter to ohms and attach one lead to each end.. div/12 to get the resistance per inch..

OR, you can take alligator clips and clip one on one end of the wire.. and then slide the other one down the length of the wire and watch the resistance change as you go.. Then stop where you want.

And that is the resistance in that given length of wire.. Then you can coil it or whatever.

To my knowledge, that's a perfectly acceptable method of checking resistance. (It's certainly fine for any other application I can name)

If you have any questions about it after you coil? Attach each lead to the ends of the coil to check resistance through the finished coil.

EDITED TO ADD:

Do not short the loops of the coil together.. Because, if you do then all of your measurements become useless, the resistance will go WAY down, and it'll burn.. And it might damage your battery, because the lower the resistance goes, the closer you are to creating a dead short.

 

[edyle]

Good info mate. Oh yeah thinking about it is the length that'll matter. So I would have to try wrapping it (for example to get an approximate length), put it through the base of the protank and then use the ohm meter to check.



Will be using a screw if all else fails Not sure what equation to use to divide? Do you mean that meter can actually measure resistance without me having to go through the hassle of coiling then putting into the base before measuring?

You don't have to wrap it first to get the length, you put the meter on the wire first and check what length gives you 2 ohms, then you know that's the length you want to use to make the coil.

Using Nataani's numbers:

Example:
28 gauge - 0.44 ohms/inch
30 gauge - 0.70 ohms/inch - (0.26 difference from 28 gauge)
32 gauge - 1.09 ohms/inch - (0.39 difference from 30 gauge)

2 inches of 32 gauge would be about 2 ohms.

So you're going to want the coil to be 2 inches at the end of the job; the coil wraps itself might be 1.5 in, and the two legs going down to the grommet would be about 1/4 inch each,

 

[Jh_X]

You don't have to have a "special' Ohmmeter to measure resistance through an E-Cig coil.

I know they show them in the videos and stuff.. Probably because they're cool? Or maybe to sell you one.. But any digital multimeter will work fine.. (Maybe better)

Or, if it's quality wire that has a uniform gauge, tables like the ones posted in this thread should be very accurate..


But there's no need for fancy gadgets.. Unless you just want them, that is..

(And who doesn't? They're pretty cool looking.. )

 

[bulldog63h]

Just remember to never get complacent. Don't get too comfortable with building and stop checking new coil builds. Your vamo should keep you safe if you have a short but it's best to not take that chance. Good luck with your first build.

 

[Nataani]

Here is the chart of wire resistances that I refer to, experimentation has shown it to be accurate with the 26, 28, and 30 gauge wires. I don't use 32.

Kanthal A1

You don't have to wrap it first to get the length, you put the meter on the wire first and check what length gives you 2 ohms, then you know that's the length you want to use to make the coil.

This unfortunately isn't always true. My fluke will measure the resistance without issue, the multimeters we last purchased for my classroom don't - much to my dismay - that is even when using alligator clips.

If you have an android device, check out vapers toolbox, it is an awesome program which should give you some good ballpark figures to use.

Vaper's Toolbox

 

[wulfenstein311]

consider twisting your 32g wire by taking a loop of kanthal 2x the length of the wire you want to work with, looping it around a right angled bit in a drill and spinning till the loop breaks. lowers your resistance and makes the microcoil more sturdy, i currently have a 1.5mm inner diameter microcoil at 1 ohms with 5/4 wraps, hits like a champ. have used the same twisted wire to make a 1mm inner diameter nano coil, with 9/8 wraps coming in at 1.6 ohms


5/4 1 ohm twisted 32g microcoil

 

[wagiman boch]

i use multimeter
you must use it to

 

[Nataani]

If you want to use a multimeter, keep a couple things in mind:

1) Do not touch the metal parts of the probes, at all. This will influence your results.
2) You must keep it as sturdy as possible, moving the probes while measuring will also influence your results.
3) As a result of 1 and 2, consider getting alligator clip extensions, they will make life a lot easier.
4) Always zero the multimeter. Not all have this function, if yours doesn't then touch the probes together and take note of the reading and subtract this from your final results.

To properly use one:
1) Zero your multimeter as described in 4 above.
2) Attach one clip to the bottommost pin of the coil head.
3) Lay the entire assembly on a non conductive surface, like wood
4) Attach the second clip to the body of the coil head (just below the threads)
5) Take note of your result and subtract your zero value from the final result.

Something to keep in mind with multimeters - they really aren't created equally. Some cheap multimeters can be great, others can be complete garbage. The best of the cheap multimeters that I have encountered are the commercial electric ones sold at home depot. The small one will automatically adjust its range for you, making it very easy to use for someone not familiar with them.

Really though, for the purpose of coil building... just get your hands on one of the little black box things. Measure a coil on your vamo, borrow a multimeter from your local brick and mortar, etc, and compare the results to your black box. The boxes have no zero function, so it is very important to figure out exactly what its error is.

To be honest, the vamo is probably one of the better meters you can find. Double checking is always good though.

 

[PLANofMAN]

i use multimeter
you must use it to

Or he could use his Vamo. I think that has already been pointed out.

 

[MassiveKlouds]

I did a dual 9 wrap of 28g kanthal cotton build & got .8ohms. 5 wraps gives me .5ohms. I measured it by an ohm meter I got from my local vape shop.

 

[Nouseforanick]

Still cant get myself use to sub ohm thou.

Current micro coil at 2 ohm, 8 rounds of kanthal a1 32gauge around a 18 gauge syringe needle.

 

[maxd]

Still cant get myself use to sub ohm thou.

Current micro coil at 2 ohm, 8 rounds of kanthal a1 32gauge around a 18 gauge syringe needle.

how big are your leads/tails ?

you might want to take lower gauge OR to do dual coil.

 

[cramptholomew]

OOOPS! Foot in mouth. Sorry for harping on the ohm meter, I didn't see that you had a VAMO. Still, I agree with everyone who said to get a Digital Multimeter. They're a VERY useful tool for our needs.

 

[Nouseforanick]

how big are your leads/tails ?

you might want to take lower gauge OR to do dual coil.

Leads and tails is probably about 2mm each.

Cant handle anything below 1.4ohm for now..Most of the time i would choke or cough after that..So probably sticking with 2ohm for now.

 

[Keeferes]

Hi guys,

Just got into making my own coil and was wondering if you guys could comment.

I was planning wrap my coils around the tip of the juice dripper. My coil is a kanthal a1 wire 32AWG.

I want to achieve 1.5-2ohm. To reach 1.5ohm how many wraps do I need? I am using a Vamo V5 and Protank 2/2 mini.

Any advice will help thanks

You should be able to find everything right here.
Loads of links for coils, safety, battery info, etc.