I THINK I AM LOSING MY MIND!

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Two_Bears

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Here is what happened today when building an Orchid.

7 wraps around the shaft of the little blue screwdriver. Using 26 gauge Kanthal. Single coil.

Tightened the screws for a nice snuv fit.

Pulsed the coil to see the starting resistance. .78 ohms exactly where I wanted it.

Now time to dry burn the Kanthal. After dry burning the resistance fell to .26 ohms. I checked the screws at least 5 times each. Still good and tight but still read .26 ohms. Just to test I wicked the coil and juiced the wick. I filled the Orchid. Gave the Orchid a few dry puffs to make sure there was sufficient vacuum to saturate the wick.

I fired the mod and now it reports my coil is operating at .67 ohms. Almost where I wanted it .8 ohms.

This is the first time I ever saw resistance fluctuate by a full 1/2 ohm then almost back to normal after wicking and juicing the coil and the screws were tight every time I checked them.
 

Two_Bears

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Coil a little too close to the chamber barrel maybe? That can cause a bit of change in the resistance.

Nope. The coil was not touching anything when it was reading .26 ohms. After I put the Orchid barrel and chimney on and had it wicked and juiced the resistance changed from .26 to .67. Several hours later it is still reading .67.
 

ccwaters

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only other thing I could say is that contact coils when initially fired can have hot spots, essentially parts of the coil are conducting with the neighboring wrap/s a micro layer of oxidation needs to build up to prevent it from bypassing portions of the coil. Probably just was not oxidized enough, even though it appeared to fire properly. Sort of an over complicated way of saying you probably just had a hotspot.
 
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UncleChuck

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Loose screws will make resistance go up, not down, and the coil you have should be way higher than .26, your target resistance sounds about right. This means there is a short somewhere.

Like others mentioned a short from one wrap to another is common and would be the first thing to check. After that make sure the legs extending from the back of the posts aren't touching anything like the deck, the chimney top (small clearance between the top of the chimney and top of posts) or each other. If resistance issues are still present then there is a short somewhere within the deck itself, maybe a worn center post insulator allowing something to short out under certain conditions. Check your resistance with the build deck empty and make sure it reads open.

I would strongly suggest taking your mounted coil and spreading it out with a small pick or screwdriver, enough that you can clearly see between every wrap and be certain no wraps are touching, then read your resistance. If it goes back up to your desired range that's evidence that there was some shorting between wraps. This is really more of a diagnostic as you will probably deform your coil a bit, best to re-wrap a new one once you've nailed down the source of the resistance issues.

Also, when assembling the built orchid, check your resistance after you wicked and juiced it, then check your resistance immediately after screwing the chimney on. If there is any variance your coil is touching and needs to be moved in a bit.

Hope this helps! Good luck!
 

Two_Bears

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only other thing I could say is that contact coils when initially fired can have hot spots, essentially parts of the coil are conducting with the neighboring wrap/s a micro layer of oxidation needs to build up to prevent it from bypassing portions of the coil. Probably just was not oxidized enough, even though it appeared to fire properly. Sort of an over complicated way of saying you probably just had a hotspot.

No hot spots or hot leg. The coil was glowing from the inside out and the color of the rising sun. The coils resistance just fell through the floor from .78 to .26. After wicking and juicing and filling the little Orchid the resistance came back up to .67 and has been .67 ohm all afternoon solid as a rock, and just checked it: still .67 ohm.
 

Two_Bears

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Loose screws will make resistance go up, not down, and the coil you have should be way higher than .26, your target resistance sounds about right. This means there is a short somewhere.

Like others mentioned a short from one wrap to another is common and would be the first thing to check. After that make sure the legs extending from the back of the posts aren't touching anything like the deck, the chimney top (small clearance between the top of the chimney and top of posts) or each other. If resistance issues are still present then there is a short somewhere within the deck itself, maybe a worn center post insulator allowing something to short out under certain conditions. Check your resistance with the build deck empty and make sure it reads open.

I would strongly suggest taking your mounted coil and spreading it out with a small pick or screwdriver, enough that you can clearly see between every wrap and be certain no wraps are touching, then read your resistance. If it goes back up to your desired range that's evidence that there was some shorting between wraps. This is really more of a diagnostic as you will probably deform your coil a bit, best to re-wrap a new one once you've nailed down the source of the resistance issues.

Also, when assembling the built orchid, check your resistance after you wicked and juiced it, then check your resistance immediately after screwing the chimney on. If there is any variance your coil is touching and needs to be moved in a bit.

Hope this helps! Good luck!

I know what a short in a coil looks like. Different colors in the coil or a few sparks.

There was none of that. Glowing from the inside out and glowing the color of the rising sun. The coil was absolutely perfect. Was not touching the deck legs trimmed. Put on the chimney. Same thing .26 ohm. Fired it to see if it would short to the chimney.

Removed the chimney wicked and juiced everything. Put the chimney on again and filled the tank.

I pressed the Fire button and now it read .67 ohm and vaped it all afternoon. It has been .67 ohm every time I checked. I checked a few minutes ago and still .67 ohm.

It is normal for the ohms to go up a few hundredth's of an ohm bit for a coil to fall .52 ohms was new and unexpected.

All I can think was the Kanthal had a fault inside the wire.
 

Elizabeth Baldwin

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I think he means there could have been a hot leg for a moment but it worked itself out. I've had that happen before. As long as it's reading a consistent ohms now I wouldn't worry. When a new coil first fires up it may fluctuate for a second until the wire gets fired up good.
 

Two_Bears

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I think he means there could have been a hot leg for a moment but it worked itself out. I've had that happen before. As long as it's reading a consistent ohms now I wouldn't worry. When a new coil first fires up it may fluctuate for a second until the wire gets fired up good.

All the time dry burning and checking for shorts against the chimney it read .26 ohm .52 ohms lower than where it started.

Instead of tossing the coil I wicked and juiced it. Filled the Orchid and fired to vape the tank and surprise the ohm rating was .67 ohm solid as a rock all afternoon. I checked 3 hours ago and still .67 ohm. I think there was some imperfection in the Kanthal.

I wanted a .8 ohm coil and got a .67 ohm coil.
 

Elizabeth Baldwin

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All the time dry burning and checking for shorts against the chimney it read .26 ohm .52 ohms lower than where it started.

Instead of tossing the coil I wicked and juiced it. Filled the Orchid and fired to vape the tank and surprise the ohm rating was .67 ohm solid as a rock all afternoon. I checked 3 hours ago and still .67 ohm. I think there was some imperfection in the Kanthal.

I wanted a .8 ohm coil and got a .67 ohm coil.

It's one of those anomalies one can't explain. :vapor:
 
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