Coil Build / Prep --- Over Temp

[PhantomOp]

Ok ... so I'm looking for what I did wrong to get these results.

Coil Build
SS316L -- Twisted 26awg core (x2) with a 36awg wrap
Twist pitch measured in at 3.1115mm (1.225in / 10)


Coil Prep
3.5 ID at 9 wraps
Steam-Engine wire wizard is showing this should have come in at 0.478 ohm, however the meter shows it at 0.74 ohm. When two of them are placed on the deck it is coming in at 0.37 ohm.


Issue
Mod Used to fire the coil: RX200S with (x3) LG-HE4 Batteries

When I was firing up the first coil (left coil in the image), before adding the second coil, everything was going smooth as usual and I got the coil firing nicely. I then added the second coil to the deck and started to prep it after checking the ohm reading. Still within good specs. I had the watts set to 10W as I did when firing the first coil. Neither coil would heat up so I then took the watts to 15 watts... same thing. I then took the RX to 20 watts and the coils started to heat up. About 2 minutes into trying to get the second coil to heat nicely I noticed that the RX was getting warm. I then looked at the screen while running through another button cycle and the LCD displayed "Over Temp".

At that very moment I stopped, pulled the batteries and removed the deck.

So, before continuing anything with this build .. what did I do wrong or not pay attention to?

 

[BKTOAD]

I am guessing you damaged a wire. Probably by over-tightening post screws. That or under-tightened the post screws and one is not making good contact. Try to tighten them up a bit. If no change, then might have kinked/nicked the core wires in the posts. Look in the postholes when you try to fire them. Do you see a red glow inside the post holes? If so, toss the coils and start over.


Your build resistance should be .24 ohms. (Dual .48ohm coils)

There is always gonna be a slight variance, but if you are getting .37 ohms, that would indicate a problem to me.

 

[BKTOAD]

Those twisted core claptons take forever to ramp, forever to cool down, and I have had the aforementioned glow in the post with them. A fused clapton vapes way better, is much less springy, and eats (wastes) less battery.

 

[PhantomOp]

I do like the fused Clapton, I can make those real easy.

So your thinking the steam engine calc is spot on (as I do) and the build is crap. I can agree with that.

The post screws are nice and tight, checked again.

If parallel Clapton's are better I'll just stick with those and start learning a new coil.

Sent from my XT1650 using Tapatalk

 

[HondaDavidson]

I have noticed that steam calculates twisted wire a little differently between it's wire wizard and coil builder. It's always close, closer than other calculators I have used. But not perfect. Also small errors to the pitch calculation can make a big difference. also the tension used in both the twisting and coiling processes can also affect the accuracy a little. Add a clapton wrap to the equation. there is allot of room for error in the math to pop up.

 

[HondaDavidson]

I do like the fused Clapton, I can make those real easy.

So your thinking the steam engine calc is spot on (as I do) and the build is crap. I can agree with that.

The post screws are nice and tight, checked again.

If parallel Clapton's are better I'll just stick with those and start learning a new coil.

Sent from my XT1650 using Tapatalk

With a multi wire build, especially wrapped core builds, a tight screw doesn't always mean good contact.....

 

[BKTOAD]

Yep, would start over.

Wire is cheap. If it does not clock in to within like .05 ohms of the steam engine calculation, even after minor tweaking, something is wrong and it needs replacement.

Fused clapton are "parallel clapton"

Idk if you know this or not, so gonna throw it out there. SS wire rises in resistance when heated. So gotta check resistance when the wire is "cold"

 

[PhantomOp]

Fused clapton are "parallel clapton"

Yup, that one i've learned from lurking in the coil forum.

SS wire rises in resistance when heated

Learned that one also by lurking. The resistance readings were taken while coils were cold. I waited 5min after placing the second coil into the deck to get a reading on the two.

 

[PhantomOp]

Look in the postholes when you try to fire them. Do you see a red glow inside the post holes

Put the deck back on the RX this morning and bumped the trigger a couple of times. Couldn't see any arcing or red glowing in the post holes.
Coils did start to bump hot but I didn't finish them out.

Pulled and trashed. Moving onto a new wire build.

BTW --- You guys are really making me want to learn the alien build ... i don't think i'm there yet though.

 

[PhantomOp]

Found it! While pulling out the second coil (very colorful one), I found that the leg under one of the post holes was 98% cut off and not just "squished" under the grub. ... to tight again. Guess I learned a good lesson on that one. Don't f*cking over tighten the shit down.

That is one of my "grumbles" about this Twisted Messes (squared) deck -- I don't have any more to compare to yet. The post holes go all the way through the deck, they aren't a solid bottom. So the wire will "bend" down into the base hole while your tightening up the grub. This coil was bend down into the hole and broken.

 

[gbalkam]

Some people really like the SS core wires. They have a cleaner taste than NiChrome or Kanthal, however, the resistance is lower. So it takes more power to heat and causes your atomizer to heat more per "hit". Which of course can cause your mod to over heat. To solve this, I started using a heat sink. There is a little bit more sag, but sag won't cook my IC board. Now, me, personally, I like the NiChrome core wire wrapped in SS. Some ppl do, some ppl like just straight SS.
Parallel coils are cool as hell. You can do a lot by adding strands of wire and changing the gauge of wire you use. Hell of a lot of math involved though. lol. Just fer-instance.. I have a RBA mini... 18 wraps of 32ga ss. Now 18 wraps of 32ga ss has a resistance of over 5 ohms, far above what my mod will fire, so to solve this, i used 6 wraps of 3 strand parallel 32ga ss. Same 18 wraps, but only 0.58 resistance. I think my next build will be the same, but 7 wraps.
I just had a thought about making a 3 core zipper coil and a video of me making it. However since my last attempt was a dismal fail, and I don't think my variety of expletives would go over well in the forum... it probably wouldn't be a good idea. LOL. I can swear fluently in English, French, German and a little bit in Chinese. (This is what happens when you mom works in a Chinese restaurant and the owners kids are babysitting... you learn new things.. )