Temperature control throttling down to 10-15 watts even at 500F?

[jersey_emt]

I just got my first temperature control mod, a Joyetech Cuboid. I picked up a variety of wire -- nickel, titanium, and stainless steel (316L) each in 26 and 28 gauge. I've only built two coils so far, so it's probably just a learning curve issue, but I figured I would post to see if there is something I'm doing obviously wrong, or if this is just normal for temperature control coils (I vape exclusively on RDA's and don't have any temperature control tanks with prebuilt coils to compare to).

First was a 28 gauge nickel build, 2.5 mm, 11 wraps, which meters out at 0.13 ohms. Second was a 26 gauge titanium build, 2.5 mm, 7 wraps, and meters out at 0.25 ohms. Both coils are spaced closely (about two wire diameters between wraps) but evenly, and the wraps are not touching anywhere. Post screws are very tight, and the coils did not budge one bit when jiggling the excess wire before clipping it.

It seems like most people vape TC coils at around 400-440F, so I started at 400F. I'm getting barely any vapor, and the Cuboid is throttling down to under 5 watts. Same deal at 440F and it is throttling down to around 7 watts. I went all the way up to 500F, and it throttles down to 10-12 watts or so, but I am starting to get a little bit of vapor.

There are absolutely no burnt hits even when the coil is getting dry, and the cotton isn't being singed, but vapor production is nothing compared to my Kanthal builds even when I go down to 20-25 watts (I usually vape at 50-60 watts), and nothing like the videos I've seen of people vaping TC coils at 400-440F.

I didn't want to go any higher than 500F before checking in here, because something seems seriously wrong. I'm not getting any "heat" at all even at 500F -- the vape is ice cold compared to what I'm used to. Any ideas?

 

[93gc40]

If your TC mod only need 10 watts to maintain a set temp, thats what is will supply. 28awg Ni at .13 ohms has a heat flux of 90 at 10watts. Yeah on the coolish side but maybe enough to maintain temp..... What is it firing in the first second on a cold coil? My guess it's starting at around 20-30 or more. then backing off when coil gets to temp. Think of a fast car.... Might take flooring it to get to 100mph before the next stop light..... BUT, once you get to 100, you no longer need to keep the pedal on the floor, you can back off to almost nothing.

Could also be a defective mod.

 

[edyle]

use steam engine

Coil wrapping

 

[edyle]

try this

Coil wrapping

titanium
3mm
11 wraps


should work out to 0.5 ohm; 35 watt

 

[Pete54]

Did you lock in the resistance while both atty and mod were cold? What you're describing usually happens when the resistance is not properly locked in.

 

[jersey_emt]

Yes, the resistance was locked in at room temperature.

To test the heat flux idea, I made a twisted 28 gauge dual coil titanium build which measured at 0.17 ohms, and things are much better. I still have to set the temperature at 500F+, but now I'm at least getting good vapor and flavor. At 520F and set to 60 watts, it stays at 50-60 watts for a few seconds then throttles back to 40-45 watts.

I just can't understand how people are getting so much vapor on a simple 28 gauge single coil nickel or titanium build at ~420F. I'm now getting more vapor than what I see in those 28 gauge single coil build videos, but to do so I need not merely a 28 gauge dual coil, but a twisted 28 gauge dual coil, and I have to bump up the temperature to 520F.

 

[Nikea Tiber]

First of all, ditch the nickel, it is more trouble than it is worth. Out of the three wires, SS is the easiest to work with. I'd start with the 26 gauge. I'll assume you can make good, consistent coils and can make pairs that heat evenly. When you build with ss you will need to pulse it until the coils heat evenly from being cold without forming any obvious hotspots.

To be honest, it sound like your issue is wicking. The two main sources of heat exchange from the resistance coil are (in this order): vaporization of juice, and airflow.
Your mod estimates how hot your resistance wire is by measuring its resistance (which varies in proportion to its temperature). If it heats up extremely quickly due to inadequate juice flow, your mod will throttle the current to keep the resistance wire within your specifications. This presents itself as weak vapor production.
Watch some wicking tutorials on YouTube, commit to one method, and master it before trying other methods. The minimum inner diameter I have ever had good success with for tc (or really anything above 35 watts) is 2.3mm, cotton or rayon.
By the way, most of my 26g ss coils have a resistance of .2 to .3 ohms, depending on inner diameter and wraps. They fire and fog fine with my wattage throttled at 45 watts and the temp limiter set to 390-430F. With TC sometimes setting the wattage control too high will cause the coil to heat too quickly to control properly. Small naked wire tc coils typically don't need over 50 watts.

 

[jersey_emt]

Thanks for the reply Nikea, but wicking isn't the issue -- with Kanthal, I build simple (one strand of wire) single macro coil builds that wick quickly enough to be vaped at 60+ watts, and simple dual macro coil builds that can run at 130 watts without any problems (I use Koh Gen Do Japanese cotton as my wicking material). Before posting this thread, I experimented with wicking TC coils, trying both more and less cotton than I use with my Kanthal builds after wicking them the same didn't work well, trying to figure out if TC coils required a different amount of cotton than traditional Kanthal coils.

 

[Hdivr]

Which mod are you running? I use TC with a DNA40 and I know for experience that if I build a coil below .15 ohms (titanium), the mod doesn't like it. Very little vapor production. Higher than .15+, great.

Another thing I've found, sometimes I build a coil and it won't give hardly any vapor. I have to clean the threads on my atty AND the 510 insert with a little alcohol and a q-tip. Then bam, fantastic vapor.

Even though the mod says everything is o.k., cleaning those two things are a must. I think liquid gets in there and does a light shellacking and hurts current flow.

 

[wLyFbR9i]

Thanks, Hdivr! I had similar problems and forgot about cleaning the 510 connections.