hot legs on coil, anyone know why they occur?

[paulw2014]

In my previous attempt to build my own coil, I got a bad burnt taste. Turning off the light, I noticed that the whole coil was glowing, even the legs.

But when I see youtube videos of others' build, the coil only glows in the middle, and the legs don't glow. Some people suggested that dry burning it and then pressing the coil together will solve the problem. I have yet to try that, but I'd like to know why that is.

It's also interesting to me how only the middle of the coil glows when it's done right. From physics class, I thought electrons travel one way so shouldn't the whole coil glows no matter what you do?

thx

 

[ScottP]

Electrons do only travel in one direction in DC circuits...from Negative to Positive. In AC circuits the Pos and Neg alternate so while the electrons still travel from Pos to Neg that path is reversing back and forth.

As to your main question I actually don't remember. I learned this back around 1992-93 and haven't used the information since. I think it had something to do with bends in the wire and eddy currents.

 

[twgbonehead]

The whole coil is made of resistance wire, it will all glow.

In a microcoil build (where the loops of the coil are very tightly packed together) the coil will start glowing in the center, and the glow will work it's way out to the ends. This is because the adjacent turns heat each other up, so the center heats up the fastest. With a looser coil this effect is much less.

There's nothing wrong with the whole coil lighting up, "hot legs" are when the leg of the coil heats up but the rest does not (usually caused by a short somewhere).

 

[hfornazier]

Which coil you 're using ?

 

[Sthur]

Try heating up the coil and the grab a pair of plyiers and pinch the coil without pressing the fire button. Repeat once or twice and coil should act a little more normal. Also make sure the coil is not touching the deck or another coil.

 

[paulw2014]

Try heating up the coil and the grab a pair of plyiers and pinch the coil without pressing the fire button. Repeat once or twice and coil should act a little more normal. Also make sure the coil is not touching the deck or another coil.

I ordered both the 30 gauge and 27 gauge kanthal. Here's is what I'm planning to do:

1. I'm going to get some 16 gauge needles to wrap the coil around.
2. Then I will attach the coil to the RM2
3. I "dry burn" it and then tighten the coil with a plyer. (This should get rid of the hot legs supposedly)
4. Then I insert the wick. I bought the silica wick, but I wonder if I should use cotton?
5. Trim any excess.

Is this the correct way?

 

[ScottP]

Wick length is going to depend on what you are building it for. For dippers you want the wick laying around on the deck to soak up liquid that is there and also holds more liquid.

 

[Zealous]

I ordered both the 30 gauge and 27 gauge kanthal. Here's is what I'm planning to do:

1. I'm going to get some 16 gauge needles to wrap the coil around.
2. Then I will attach the coil to the RM2
3. I "dry burn" it and then tighten the coil with a plyer. (This should get rid of the hot legs supposedly)
4. Then I insert the wick. I bought the silica wick, but I wonder if I should use cotton?
5. Trim any excess.

Is this the correct way?

Yes, this is basically it. You don't want to trim the wicking too much though so it can absorb the eliquid. But on a RM2 it doesn't need to be very long. If you want to use silica you can but threading cotton through is easier. HST there is a thread in the Reo subforum with someone showing an easy way to thread silica through a coil. I've done it with his method several times & it is pretty easy. the thread's not stickied so you'll have to do a search for it there.

Yay I found it. For threading silica into a microcoil: http://www.e-cigarette-forum.com/forum/reos-mods/471568-micro-coil-silica.html

 

[Visus]

Theres so many vids on youtube that show how to make a micro coil you will get it good if you try.

BTW if the coil is built right, "the legs" will never glow ever, they are just vehicles transmitting the electrons..

The guys in this section are amazing coil builders and can help point or direct ya the rights..
Rebuildable Atomizer Systems