Dual Coils not firing equally

[Diche]

I decided it was time I put a new set of coils in my tobh. My first set worked well, but they were a little small in the bore and fiddly to wick with cotton, so I am going for something slightly larger this time. The other issue I had was one of them always heated up marginally faster than the other. It was quite a minor difference, but annoying all the same. I am having the same issue with my second set and I just wanted to check my understanding of the reasons.

I think it must be essentially caused by one having a very slightly higher resistance than the other. This could be due to:

Longer leads on one of the coils
More wraps on one coil than the other (it's not this I am not quite that dumb but I included it for completeness)
One coil more compressed than the other? (not sure of the mechanics of this one but I think it is true)



Have I missed any possible variables and causes out? Any help much appreciated

 

[Tubbyengineer]

I decided it was time I put a new set of coils in my tobh. My first set worked well, but they were a little small in the bore and fiddly to wick with cotton, so I am going for something slightly larger this time. The other issue I had was one of them always heated up marginally faster than the other. It was quite a minor difference, but annoying all the same. I am having the same issue with my second set and I just wanted to check my understanding of the reasons.

I think it must be essentially caused by one having a very slightly higher resistance than the other. This could be due to:

Longer leads on one of the coils
More wraps on one coil than the other (it's not this I am not quite that dumb but I included it for completeness)
One coil more compressed than the other? (not sure of the mechanics of this one but I think it is true)



Have I missed any possible variables and causes out? Any help much appreciated

Poor connection on one of the coils increasing its resistance... Same coil every time would point to the negative post for that coil...

 

[Diche]

Poor connection on one of the coils increasing its resistance... Same coil every time would point to the negative post for that coil...

I am not sure how it could be the negative post, the tobh deck and neg posts are all kinda one piece. Though I have to admit the screws have a wonderful habit of undoing themselves.

 

[BAVapes]

When this happens to me I adjust the leg lengths, the one that is heating up slower needs shorter legs. That usually sorts it out. Make sure they're all compressed properly too.

 

[sparkyjuice]

More likely like you said if micros then one coil closer set than other it's very hard to make two identical coils Diche


Sent from (who cares) using Planet of the Vapes

 

[Diche]

Got the little bastards

 

[Gandalf]

Got the little bastards

I know it's the little things that annoy us but I really wouldnt worry too much as long as both coils are working. How much will you notice when its all together and your sucking away

 

[Diche]

I know it's the little things that annoy us but I really wouldnt worry too much as long as both coils are working. How much will you notice when its all together and your sucking away

I noticed on the last set of coils that I was getting dry hits off one coil when the wick on the other coil was still quite soggy, a minor irritation, but irritating none the less.

 

[StuPot]

You'll get this less with thicker wire as when you've squeezed them together they stay together.

I usually build it and fire it without cotton, then squeeze the coil that's glowing first, repeat until they glow evenly.

I'm surprised no one else has said this yet. I always have this problem even with identical coils.

Also make sure the screws are quite tight, like you say, they loosen themselves when adjusting the coils.

 

[Diche]

You'll get this less with thicker wire as when you've squeezed them together they stay together.

I usually build it and fire it without cotton, then squeeze the coil that's glowing first, repeat until they glow evenly.

I'm surprised no one else has said this yet. I always have this problem even with identical coils.

Also make sure the screws are quite tight, like you say, they loosen themselves when adjusting the coils.

Yes that is the process I have been using, but on the first set of coils I was trying to fit tonight even that wasn't solving the issue. I still have no idea why they weren't playing ball, I cut my losses and started again. With the second set it only took a couple of minor adjustments to get them glowing nice and evenly.

I am using 0.3mm kanthal at the moment and I have some 0.32, both of which are pretty fine I think. What grade would you suggest I pick up on my next shopping trip? Bear in mind I am looking to produce 1-1.2ohm coils.

edit: I guess that should read 2-2.4ohm coils or 1-1.2ohm setup