Couple of questions about rebuilding nova's or anything similar

[Timboo]

1. When I rebuild the Nova I find it looses a lot of flavor and throat hit compared to the one that was originally installed?

I use silica wick.

2. Sometimes when I rebuild it the center stem gets very hot. Why is this?

 

[Timboo]

anybody?!.................

 

[Ken_A]

you may be wrapping too tight. try using a pin. align the wick with the pin, wrap the wire then remove the pin. Then the wire will not be choking the wick.
I use 3MM wick and 32 Gauge Kanthol wire. 5 wraps is about 2.5 ohm.

 

[AttyPops]

Give us more specs about the wire and ohms and # wraps ......also voltage.

Also, did you test for any shorts? Even a semi-conductive spot can cause heat. How did it meter out? Also, avoid getting coil too close to edges. You don't want the center stem (not talking center post here) to conduct from the top at all, just the return-wire (ground wire) to bottom edge of head (threads).

 

[sailense]

1. When I rebuild the Nova I find it looses a lot of flavor and throat hit compared to the one that was originally installed?

I use silica wick.

2. Sometimes when I rebuild it the center stem gets very hot. Why is this?

Hot spots. One of the legs, most likely the negative lead, has a hot spot and is transferring heat to the center stem. The factory made coils usually have almost perfectly straight legs to avoid hot spots. This is much harder to do when you do your own, especially with Nova's and other types that aren't made to be rebuildable.

 

[sailense]

In fact, a lot of the disposables that I've taken apart have used no-resistance wire for the legs that's been welded to the coil.

DIYers have been able to make coil welders using old camera flash bulbs, like here: The Spark-O-Matic - Coil Wire Arc Welding

 

[AttyPops]

In fact, a lot of the disposables that I've taken apart have used no-resistance wire for the legs that's been welded to the coil.

DIYers have been able to make coil welders using old camera flash bulbs, like here: The Spark-O-Matic - Coil Wire Arc Welding

One thing people do is double up the legs to/from the coil too (reduces resistance on the legs so they don't glow).

I posted an alternate wrapping too quite a while back. Center wire in center (doubled) coils go from center to near each side, then down to ground (so there's 3 legs, 1 center doubled and 2 ground). Still, don't let them short to the stem. Never got attention. Basically it's what dual coils do.

The arc welder probably works but it's probably a bit dangerous and a PITA to do, IMHO.

 

[Timboo]

Thanks a lot for the tips everyone.

The recent coil was 1.7 ohms using 0.20mm kanthal wire with four strands of 1mm silica wick. Wrapped four times. I have not tried to vape it as it gets hot but I dry burned the coil at 4 volts.

I do tend to wrap them tight as that's what I thought you were supposed to do. I shall try doing it looser.

The legs are definitely straight when I installed them. The coil glows up nicely just all gets very hot so something must be wrong.

Looks like i am going to do some more research as I do not understand double legs!

I watched loads if tutorials on rebuilding these but there is still clearly something I am not doing right.

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[Timboo]

Reading back on my first post I meant the head gets hot which then makes the center part hot and so on.

Hopefully my question has not confused any matters.

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[Timboo]

Attypops: I check for shorts on my Vamo if that counts. I would presume it would not work if it had a short.

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[AttyPops]

The juice flow cools the coil. If you're wrapping too tightly and no juice gets to coil, it's gonna get real hot real fast....

 

[Timboo]

Ok that could well be my issue. I shall report back when I get a chance to rebuild it

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[Myk]

Hot spots. One of the legs, most likely the negative lead, has a hot spot and is transferring heat to the center stem. The factory made coils usually have almost perfectly straight legs to avoid hot spots. This is much harder to do when you do your own, especially with Nova's and other types that aren't made to be rebuildable.

You have got to be kidding. On every factory coil I've had to take apart to get to read or read close to the rating there was a bunch of extra wire and the legs were basically loose coils.

 

[Timboo]

No difference really do not understand what i am doing wrong!!!

 

[sailense]

You have got to be kidding. On every factory coil I've had to take apart to get to read or read close to the rating there was a bunch of extra wire and the legs were basically loose coils.

I've seen that on knockoff Vivi Nova's, but all the Vision one's I've pulled apart have had straight legs.

 

[sailense]

No difference really do not understand what i am doing wrong!!!

Try vaping with the rubber cap off. If it vapes better, it's a wicking issue. You can also dry dry pulsing a few times. Some coils I've done needed breaking in.

 

[Myk]

I've seen that on knockoff Vivi Nova's, but all the Vision one's I've pulled apart have had straight legs.

All of mine are Vision. I've only carefully taken apart new ones that weren't reading right.

 

[sailense]

All of mine are Vision. I've only carefully taken apart new ones that weren't reading right.

I probably didn't explain it properly. I usually take my new ones apart to drill out the center post for a better draw, and the coils look machine wrapped to me with a bend at the end. Specifically the 1.8ohm, which had more wraps than the 2.5ohm or 2.8ohm. But it could just be how a difference of perception.

In the beginning, I tried to make it last longer by rewrapping busted coils. So a 2ohm would be a 1.5ohm after trimming the excess and cleaning off the wire. But I could never get the legs perfectly straight since I was working with so little wire and always had hot spots. If you have a long length to work with, it's much easier. That's the issue I was suggesting the OP was having.

 

[Timboo]

It's not the breaking in that's the problem, it's the whole thing heating up. I'm starting to give up on nova's. Got a bottom coil on the way so see how that goes.

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