Help calculating coils...

[Taledus]

I have been building coils for a few months now. I'm using 32g A1 kanthal from Lightning Vapes. I'm doing a dual coil setup with 8 full wraps on 1/16" (1.58mm) for each coil on my kayfun Lite's. I'm getting 1.5ohms consistently which is working great. Doing readings with multimeter.

Then I bought this spiffy coil wrapping jig at a craft store. The small wire for it is 1.78mm. I plugged in the numbers for it into Steam Engine and it is saying to only use 5/4 wraps for a 1.5ohm dual coil setup. To me something seemed off compared to what I am using now...so I plugged in the numbers for the 1/16" drill bit that I currently use. It too is showing to only use 5/4 wraps to get 1.5ohms.

Instead of doing a trial and error guessing session I was hoping that someone here would have a better idea of what to use for calculating coils, or perhaps a formula that I can just calculate myself.

 

[AzPlumber]

Do you have it set for dual coil (parallel)

 

[Wraith504]

I have been building coils for a few months now. I'm using 32g A1 kanthal from Lightning Vapes. I'm doing a dual coil setup with 8 full wraps on 1/16" (1.58mm) for each coil on my Kayfun Lite's. I'm getting 1.5ohms consistently which is working great. Doing readings with multimeter.

Then I bought this spiffy coil wrapping jig at a craft store. The small wire for it is 1.78mm. I plugged in the numbers for it into Steam Engine and it is saying to only use 5/4 wraps for a 1.5ohm dual coil setup. To me something seemed off compared to what I am using now...so I plugged in the numbers for the 1/16" drill bit that I currently use. It too is showing to only use 5/4 wraps to get 1.5ohms.

Instead of doing a trial and error guessing session I was hoping that someone here would have a better idea of what to use for calculating coils, or perhaps a formula that I can just calculate myself.

I dont use calculators i simply wrap and measure

 

[State O' Flux]

I believe you have it set to a single coil.

32 gauge dual parallel coils, wrapped on a 1.78mm mandrel - for a desired 1.5Ω net resistance. Is that the goal here?

Per SE, using a dual parallel coil setting... it calculates to 66.3mm of wire per coil - 9.22 (10/9) wraps... using 3mm legs.

 

[Taledus]

Do you have it set for dual coil (parallel)

Yes. I am having to set the target resistance to 0.75 ohms just to get it to 1.5...but I think I am not doing that right. If I set the target resistance to the desired 1.5 ohms it is telling me to do 10 full wraps, which is 2 more than what I am doing. With what I am currently doing I am at a consistent 1.5ohms with both parallel coils. I just have no idea how much it will change by using the coil wrapping jig with a difference of .20mm.

 

[AzPlumber]

Yes. I am having to set the target resistance to 0.75 ohms just to get it to 1.5...but I think I am not doing that right. If I set the target resistance to the desired 1.5 ohms it is telling me to do 10 full wraps, which is 2 more than what I am doing. With what I am currently doing I am at a consistent 1.5ohms with both parallel coils. I just have no idea how much it will change by using the coil wrapping jig with a difference of .20mm.

Make sure you check the coil spacing and leg length in advance settings, it may make a difference. The calculator is pretty close but will only give you a general starting point.

 

[Taledus]

I believe you have it set to a single coil.

32 gauge dual parallel coils, wrapped on a 1.78mm mandrel - for a desired 1.5Ω net resistance. Is that the goal here?

Per SE, using a dual parallel coil setting... it calculates to 66.3mm of wire per coil - 9.22 (10/9) wraps... using 3mm legs.

It is set to dual coil parallel. After setting the target resistance to 1.5 ohms, like you it is showing 10 full wraps. I am only doing 8 full wraps on each coil to reach 1.5ohms.

 

[AzPlumber]

Yes. I am having to set the target resistance to 0.75 ohms just to get it to 1.5...but I think I am not doing that right. If I set the target resistance to the desired 1.5 ohms it is telling me to do 10 full wraps, which is 2 more than what I am doing. With what I am currently doing I am at a consistent 1.5ohms with both parallel coils. I just have no idea how much it will change by using the coil wrapping jig with a difference of .20mm.

Are you trying to get a combined resistance of 1.5 or 1.5 on each coil?

 

[Taledus]

Are you trying to get a combined resistance of 1.5 or 1.5 on each coil?

I am trying to get a total of 1.5ohms on a finished setup. I was reading the target resistance incorrectly at first because I was only coming up with 5/4 wraps. Now that I have that set to the correct 1.5ohm target resistance. That makes each individual coil 3ohms each for what I am currently using, except I am reaching this with 8 full wraps instead of 10.

The rod that came with the coil jig measures out to 1.78mm. If I plug that into the calculator it says to do 9 full wraps.

What I am confused on is if 8 wraps on 1.58mm gets me 1.5ohms total, then (X) wraps on 1.78mm gets me 1.5ohm coil?

I bought a crap load of 32 gauge kanthal so I am probably just going to experiment to see what I come up with.

 

[AzPlumber]

I am trying to get a total of 1.5ohms on a finished setup. I was reading the target resistance incorrectly at first because I was only coming up with 5/4 wraps. Now that I have that set to the correct 1.5ohm target resistance. That makes each individual coil 3ohms each for what I am currently using, except I am reaching this with 8 full wraps instead of 10.

The rod that came with the coil jig measures out to 1.78mm. If I plug that into the calculator it says to do 9 full wraps.

What I am confused on is if 8 wraps on 1.58mm gets me 1.5ohms total, then (X) wraps on 1.78mm gets me 1.5ohm coil?

I bought a crap load of 32 gauge kanthal so I am probably just going to experiment to see what I come up with.

Aah I gotcha now. I would just stick with the 8 wraps as the .2 mm won't make that much of a difference.

 

[Taledus]

Alright, I used my new jig and did the same number of wraps (8 full) for both coils. It did make no difference in the 3.0ohms per coil.

However, they looked like crap and I had to use an additional inch of kanthal just to wrap it around the loop on the jig wire. Over the length of a 250' roll of kanthal that would add up. Also, the jig was more tedious to use compared to using needle nose pliers, a drill bit, and the soldering helper clamps. Maybe I was doing it wrong, but I guess if something is working well, and I am able to get consistent 1.5 ohms, then I just shouldn't change it.

Thanks for the help guys!