how many wraps on micro coil

[adlufc1141]

Hi i have some .20 and .30 A1 Kanthal

i am new to microcoils so please excuse my iggnorance

I bought some pre made coils from ebay and they are great (1.5ohm)

im going to be building my own soon

i have a 2mm drill bit and im wondering how many wraps of the coil i will need to create a resistance of about 1.8ohm?

and just for my own knowledge, generally, does increasing the wraps increase the ohm?

 

[slappy3139]

The length of the wire determines the resistance of the wire not the wraps

Sent from my SAMSUNG-SGH-I537 using Planet of the Vapes mobile app

 

[adlufc1141]

The length of the wire determines the resistance of the wire not the wraps

Sent from my SAMSUNG-SGH-I537 using Planet of the Vapes mobile app

so I could have a 2 inch wire with 2 coils/wraps and a 2 inch wire with 10 coils/wraps and it would be the same ohm?

 

[Gilliandrea]

adlufc1141

Depending on the thickness of the wire and the ohm per length

There is a chart in the wiki
http://wiki.planetofthevapes.co.uk/wiki/Kanthal_A-1

 

[ill_dawg]

Yup, wire resistance is often given in ohms per inch. More wraps on the same diameter coil gives higher resistance (increases the ohms) because you are adding more length.

 

[Billybob99]

i do 9 wraps around a 1.5mm drill bit with .25 kanthal and get 1.6-1.7ohms examples here

 

[tikkatock]

Hi mate. I've not long been playing around with an igo w and recoiling some vivi nova heads so I know where you're coming from. I'm using an MVP atm so I'm generally keeping my ohms around 1.5 +. In the last week I've found my sweet spot to be about 2.1 ohms which gives me a little room to play around with the variable wattage.
To answer your question, more wraps = higher ohms. As slappy said it's the length of the wire that gives you the resistance. Longer wire = more resistance.
.20 will give you higher resistance compared to the .30. Ive been playing with .15, .20 and .25 and have really found .20 to be the best for me atm as it heats up a little faster, is more flexible to work with and requires fewer coils for the same resistance as say .25. I've found .15 to get very hot, very quick and sometimes burns my cotton.

Truth is I think everyone's preferences are a little different and the trick to finding yours is to play around. From my experience I found a 2mm screwdriver and stuck with that for a little while as a standard. I just kept trying variations of wire size, number of wraps, cotton/silica/eko. The only bit of advice I wish I took was to write my findings down somewhere. Nothing as annoying as making a great coil/wick combo then forgetting what gauge or something it was.

Hope my ramble was helpful!

 

[Phantom Diablo]

BUT a little thing to consider. ohms law on nano and micro coils isnt accurate. becuase when you heat and compress your coil to make it nice and tight the coil merges so instead of it being say 8-10 wraps because the wire has melded it then comes what can only be considered as a single very thick hollowed piece of kanthal ( just for arguments sake 1.2mm Kathal which would then have some silly ohms resistance of say 1 ohm per cm.
I can do a 16 wrap nano coil that comes in at 0.8 ohms. but if i was to spread that same coil leaving slight gaps between each twist it would probably be something like 8-10 ohms!
this one ( 8 wraps i think ) was 0.9 ohms

Also dont get AWG and wire thickness confused beacause AWG .20 is NOT .20mm thick and 0.20mm kanthal is not AWG .20 ( 0.20mm kanthal is AWG .32 ) and very very thin and generally to springly for micro/nano coils.

look for mm thickness and anything between 0.25 - 0.32 ( i normally use 0.32 but have recently switched to 0.28 i find even 0.25 a little to thin for micro but may be ok for nano coils )
your must have tool is the ohm meter to check . also a 2mm drill bit may be a little big. you want something around 1.2-1.4mm drill bit. then about 5 wraps should do it but again its all down to how you compress the coils. gaps = higher ohms.

 

[adlufc1141]

cheers fellas and thanks for the wiki guide

im more confident in how to acheive certain ohm's now

im guessing that with using a 2mm drill bit and 10 wraps i can guess that the length of the wire will be around 7 cm?

pi x diameter x 10 (plus a little extra to reach the screw posts)

3.14 x 2mm x 10 (+ 5mm)

so going from the wiki guide a .30 wire will give me about what im looking for

EDIT.... @Phnaton now you have just thrown a spanner in the works!!!!

i guess trail and error is the key!

 

[Phantom Diablo]

lol ok well in simple tems when you wrap it and leave gaps.. its one long piece of wire.. heat that up and compress it you end up with a 1/4 inch hollow thick bit of wire. its much like twisted wraps where you get two or 3 bits of kanthal and braid them together.. if you measure say 3 lengths of 10cm .32 the ohms would be far different when those 3 lengths are braided together becuase it creates a thicker kanthal. and micro and nano coils effetively have the same effect.