HOLY COW!!! Coil building advice please.

Status
Not open for further replies.

RamShot Rowdy

Battery Police
ECF Veteran
Verified Member
Nov 6, 2009
833
507
Oklahoma, USA
I got into rebuilding late last year when I bought a Squape R. I've built numerous coils in the 1.2 to 1.8 ohm range with Kanthal. I've always run the Squape on my regulated mods in the 15-18 watt range, using 24 and 18 mg/ml liquid.

So I recently got a new mech mod and wanted to build the Squape to run in the 12-20 watt range, over the life of my battery, so I got a simlar vape to my regulated devices. Now I know mechs are supposed to have some voltage drop under load, so I figured a 0.8 ohm build would probably work. My builds always seem to come out higher than steam engine says, so I went with a five wrap of 28g Kanthal A1 on a 2mm jig. I heated and squeezed it and it was reading 1.07 ohms. So I pulled it out, increased my lead length from 5 to 10, cause 5 seemed a bit short, on steam engine, then it showed I'd get a 0.77 ohm with 4 wraps. So I did a four wrap and it metered around 0.95 ohms. It was a nice spaced coil so I didn't squeeze it. I figured it was low enough for now, so I pulled some cotton through it, wet it, and put it on my VS to test it. On the VS it was now reading 0.73 ohms, but it worked fine.

So finally put it on my mech mod and vaped it a few times, talk about a nicotine rush. Anyway, the taste isn't bad but the nicotine seems like a killer with 18 mg/ml juice.

So where did I go wrong? Why did the coil resistance change so much when I wicked and wet the coil? What ohm build do I need for that 14-18 watt vape? I think I way over estimated voltage drop.

Rebuilding is still pretty new to me, so still a lot to learn I guess. Thanks in advance for any help.
 

SLIPPY_EEL

Vaping Master
ECF Veteran
Oct 11, 2013
3,127
3,908
Ω England Ω
hmm 14-18w, i would stick with a microcoil 1/16id with the 28g A1 at about 8 contact wraps, 1.2ohms was a good vape for me when i used to vape at about the same wattage as you are.

i'm not exactly sure of what you did on your previous build where your ohms changed but your ohms will change by 0.2 if for example you built a 1ohm coil with non contact wraps and then you decided to squeeze them all together to turn it into a contact coil your ohms would then rise to 1.2ohm's.


edit:

I can't figure out why the resistance dropped 0.2 ohms when I wicked and wet the coil. It seems stronger than 18 watts, what build should I shoot for to get 18 watts. Also any tips on getting closer to what steam engine predicts?

what i do if i want to be precise without the use of a calculator is to put a free rda on the ohm meter and feed it how much wire i think i would need, tighten the post screws up, test ohms, adjust amount of wire between posts to get desired ohms etcetc :)


oh hang on a sec: i realised you are using a mech, so base my above coil suggestion on your regulated device!... to get about 18 watts you will need to goto about 5 contact wraps on 1/16id with a single coil with your mech which also allows for the gain of the 0.2 from the contacted coils
 
Last edited:

Firestorm

Vaping Master
ECF Veteran
Verified Member
Nov 25, 2012
2,882
6,566
Chicagoland
i'm not exactly sure of what you did on your previous build where your ohms changed but your ohms will change by 0.2 if for example you built a 1ohm coil with non contact wraps and then you decided to squeeze them all together to turn it into a contact coil your ohms would then rise to 1.2ohm's.

That doesn't sound right to me. The gauge and length of your Kanthal should determine the resistance, regardless of whether or not the coils touch. A small layer of oxidation builds up on the resistance wire that prevents the contact coils from shorting and should have no bearing on the resistance.
 

edyle

ECF Guru
ECF Veteran
Verified Member
Oct 23, 2013
14,199
7,195
Port-of-Spain, Trinidad & Tobago
I got into rebuilding late last year when I bought a Squape R. I've built numerous coils in the 1.2 to 1.8 ohm range with Kanthal. I've always run the Squape on my regulated mods in the 15-18 watt range, using 24 and 18 mg/ml liquid.

So I recently got a new mech mod and wanted to build the Squape to run in the 12-20 watt range, over the life of my battery, so I got a simlar vape to my regulated devices. Now I know mechs are supposed to have some voltage drop under load, so I figured a 0.8 ohm build would probably work. My builds always seem to come out higher than steam engine says, so I went with a five wrap of 28g Kanthal A1 on a 2mm jig. I heated and squeezed it and it was reading 1.07 ohms. So I pulled it out, increased my lead length from 5 to 10, cause 5 seemed a bit short, on steam engine, then it showed I'd get a 0.77 ohm with 4 wraps. So I did a four wrap and it metered around 0.95 ohms. It was a nice spaced coil so I didn't squeeze it. I figured it was low enough for now, so I pulled some cotton through it, wet it, and put it on my VS to test it. On the VS it was now reading 0.73 ohms, but it worked fine.

So finally put it on my mech mod and vaped it a few times, talk about a nicotine rush. Anyway, the taste isn't bad but the nicotine seems like a killer with 18 mg/ml juice.

So where did I go wrong? Why did the coil resistance change so much when I wicked and wet the coil? What ohm build do I need for that 14-18 watt vape? I think I way over estimated voltage drop.

Rebuilding is still pretty new to me, so still a lot to learn I guess. Thanks in advance for any help.


1: If your regulated mod can run in VV mode, try to build a coil to work at 3.7 or 4 volts on the regulated mod;
Once you get used to running toppers optimized to work at that voltage, you just use those toppers on mechs.

2: If you double the wattage, you double the amount of nicotine per vape
 

edyle

ECF Guru
ECF Veteran
Verified Member
Oct 23, 2013
14,199
7,195
Port-of-Spain, Trinidad & Tobago
I can't figure out why the resistance dropped 0.2 ohms when I wicked and wet the coil. It seems stronger than 18 watts, what build should I shoot for to get 18 watts. Also any tips on getting closer to what steam engine predicts?

Use bigger coil diameter.
 

SLIPPY_EEL

Vaping Master
ECF Veteran
Oct 11, 2013
3,127
3,908
Ω England Ω
That doesn't sound right to me. The gauge and length of your Kanthal should determine the resistance, regardless of whether or not the coils touch. A small layer of oxidation builds up on the resistance wire that prevents the contact coils from shorting and should have no bearing on the resistance.

do a test yourself and tell me what happens
 

Das Auto

Ultra Member
Verified Member
Feb 6, 2015
1,021
352
Pacific NW, USA
I've noticed that when I squeeze my coils together the resistance drops. Depending on how large of a ID I have depends on how much the coil resistance goes down.

I built a 10 wrap 24 ga coil on my Tobeco coil jig using the largest post it comes with. Ohm'd out on my DMM at 1.2. Heated them up and squeezed together and read at 1.0.
Built another coil using 24 ga on the 2nd largest coil that came with the Tobeco jig, 6 wraps, DMM Ohm'd it out at 0.7 - 0.8 (kept bouncing back and forth). Heated up and squeezed together, read out at 0.6 Ohm.

So there was little bit of change in resistance on both coils. But maybe I am just an oddball??!!
 

SLIPPY_EEL

Vaping Master
ECF Veteran
Oct 11, 2013
3,127
3,908
Ω England Ω
I've noticed that when I squeeze my coils together the resistance drops. Depending on how large of a ID I have depends on how much the coil resistance goes down.

I built a 10 wrap 24 ga coil on my Tobeco coil jig using the largest post it comes with. Ohm'd out on my DMM at 1.2. Heated them up and squeezed together and read at 1.0.
Built another coil using 24 ga on the 2nd largest coil that came with the Tobeco jig, 6 wraps, DMM Ohm'd it out at 0.7 - 0.8 (kept bouncing back and forth). Heated up and squeezed together, read out at 0.6 Ohm.

So there was little bit of change in resistance on both coils. But maybe I am just an oddball??!!

hmmm thats weird! cus if i squeeze em they gain 0.2ohms :lol: but i dont think they lose .2 ohms if i open em back up... god knows... i havent ever noticed anyone else really say about it... when i get 5 i'll do some tests, i havent bothered to concern myself over it, But yeah just curious :)
 

duc916

Super Member
ECF Veteran
Jul 10, 2012
806
729
Nor Cal
I notice a fresh build on my microcoils (compressed) always reads lower when new.... once they've been used for a tank full they go up about 0.2 ohm. the oxidation layer on the coils creates an insulation that prevent current from cutting across the windings, which just become more predictable with use.

Your mech at 0.73 ohm is at 24W (4.2V), higher than the 12-20W you've been running regulated. That's enough to account for extra nicotine. Not to mention that watt for watt, a flat DC signal is more efficient at vapor delivery than a PWM "bucked" delivery.

Gotta admit though, my first thought is... 24mg nic at 24W. Holy moly. Cut back a bit!
 
Last edited:
Status
Not open for further replies.

Users who are viewing this thread