TC and Dry Hits

[KurtVD]

Last month (or the entire last year, really, but especially last month) I was experimenting with my two identical atomizers (RTAs) in order to get rid of a problem with air trapped in the wells, leaving the cotton dry. Thankfully this problem seems definitely solved by now, but during this period of experiments, I had a few dry hits even though both of my mods are always set on temperature control, and on a rather low temperature, and I was wondering why it only happened with one of the two atomizers? One has a Ni200 coil inside with about 0.09 resistance, whereas the other is sporting a SS316 coil with about 0.6 Ohms, and that’s the one which singed the cotton. It didn’t really burn it, but it tasted disgusting and left a horrible taste in my mouth for hours, and it happened several times. Is the higher resistance of the SS316 coil the reason that it heats up more before the mod cuts or reduces the power? More resistance = more power needed = less reactive? Or are coils made from SS just slower to heat and cool down, compared to Nickel?

 

[HigherStateD]

Sounds like the TC isn't functioning properly.

It could be the mod itself, the TC settings, or the coil configuration.

Which mod, what settings are you using, and what type of coil?

Resistance has little to do with heat flux and capacity. It is only a measure of electrical conductivity.

 

[KurtVD]

Sounds like the TC isn't functioning properly.

It could be the mod itself, the TC settings, or the coil configuration.

Which mod, what settings are you using, and what type of coil?

Resistance has little to do with heat flux and capacity. It is only a measure of electrical conductivity.

TC is working, I use it all the time. I know it isn’t as smoothly or as precisely working as on my DNA 75 mod, but it’s definitely working. I have two Pico 75W running Arctic Fox, but it only happened with an SS coil, never with Ni200 coils. What do you mean when you ask ‘what type of coil’? If it’s a build like Clapton or something ‘complicated’? No, it’s a very simple, normal coil with 5 or 6 wraps, 2.5mm.

I vape at around 180-200 Celsius (350-400 F), I guess that it doesn’t need a lot more before cotton starts to singe (if it’s dry)?

 

[Mordacai]

@KurtVD, it may well be the SS itself. As it's an alloy and various manufacturers produce it to ever so slightly different formulations and either tolerances or precision.

Got myself some Ti and Ni to compare against SS316L, but from what I've been hearing I expect much better TC performance.

 

[Punk In Drublic]

TC is working, I use it all the time. I know it isn’t as smoothly or as precisely working as on my DNA 75 mod, but it’s definitely working. I have two Pico 75W running Arctic Fox, but it only happened with an SS coil, never with Ni200 coils. What do you mean when you ask ‘what type of coil’? If it’s a build like Clapton or something ‘complicated’? No, it’s a very simple, normal coil with 5 or 6 wraps, 2.5mm.

I vape at around 180-200 Celsius (350-400 F), I guess that it doesn’t need a lot more before cotton starts to singe (if it’s dry)?

Given you are running Arctic Fox, have you plotted the coils behaviour? TC may be working to your liking with one type of coil, but that does not guarantee those same settings for temperature will be optimal with another type.

 

[HigherStateD]

A plot with Arctic fox would be invaluable. Are you using the SS TFR profile? I find better results with SS316L using TCR of 96. This on a RX2 using Arctic fox. Spaced coils seem to be a little more accurate than contact also.

 

[Punk In Drublic]

A plot with Arctic fox would be invaluable.

Being able to plot the coils behaviour in real time is an extremely valuable tool when working with Temp Control.

Temperature Control is a prediction based on the coil’s rise in resistance by using a specific TCR value. @Mordacai is correct in that we do not know the exact TCR values, unless specified by the wire’s/coils manufacture. But even if we have the incorrect TCR value (within reason), we should be able to achieve a functional TC vape should the coils rise in resistance be within the temperature range we prescribed. You may not be achieving an exact 200°C as prescribed, but knowing how the coil behaves within the environment of the atomizer is it working within you should be able to easy avoid dry hits assuming the device is functioning properly. This is where the benefits of Escribe and NFE Tools comes into play. You can plot a coils rise in resistance and adjust your prescribed temperature, even with an incorrect TCR value, accordingly.

 

[HigherStateD]

Being able to plot the coils behaviour in real time is an extremely valuable tool when working with Temp Control.

Temperature Control is a prediction based on the coil’s rise in resistance by using a specific TCR value. @Mordacai is correct in that we do not know the exact TCR values, unless specified by the wire’s/coils manufacture. But even if we have the incorrect TCR value (within reason), we should be able to achieve a functional TC vape should the coils rise in resistance be within the temperature range we prescribed. You may not be achieving an exact 200°C as prescribed, but knowing how the coil behaves within the environment of the atomizer is it working within you should be able to easy avoid dry hits assuming the device is functioning properly. This is where the benefits of Escribe and NFE Tools comes into play. You can plot a coils rise in resistance and adjust your prescribed temperature, even with an incorrect TCR value, accordingly.

Yep. That's why if op posted one, it would be invaluable, ie, priceless, in making an educated guess, instead of random guesses.

 

[KurtVD]

plotted the coils behaviour?

find better results with SS316L using TCR of 96.

I think I have modified the TCR but I’ll have to check.

That's why if op posted one, it would be invaluable, ie, priceless

I will do a real time monitoring, probably today, but it’s not that easy: First I need to empty the tank and not fill it up immediately. Otherwise I won’t get a dry hit, since I don’t have the problem with the dry cotton anymore, and under normal circumstances the TC works just fine. Plus I have to start up my Mac in Windows mode, since the program isn’t available for MacOs (but that’s just me being lazy...).

 

[Mordacai]

@KurtVD, Escribe is available for MacOS.
EVOLV - Home

Download the International version and try it.

 

[HigherStateD]

@KurtVD, Escribe is available for MacOS.
EVOLV - Home

Download the International version and try it.

NFE tools is windows only.

 

[KurtVD]

@KurtVD, Escribe is available for MacOS.
EVOLV - Home

Download the International version and try it.

I have eScribe, but it only works for my DNA mod, for Arctic Fox you need another program, which is Windows only (at least that’s how it was until a few months ago)

 

[Mordacai]

NFE tools was missing from the post @HigherStateD, but there's a 3rd party software that supposedly supports MacOS.
[P11] arcticfox-config v11.0.0 for macOS and Linux

 

[GeorgeS]

Personally I use ether TI or NiFe48. Never had any temperature regulation issues with these wires.

 

[Beamslider]

In general have had better TC with coils that are spaced with 316l vs contact ones.

Put the coils into wire wizard at steam engine. See what the TC Precision number is for your coil. A higher TC precision number is better. This will also give you a tcr for the wire and let you download a table for DNA mods

Wire wizard | Steam Engine | free vaping calculators

 

[m1ke]

In general have had better TC with coils that are spaced with 316l vs contact ones.

Put the coils into wire wizard at steam engine. See what the TC Precision number is for your coil. A higher TC precision number is better. This will also give you a tcr for the wire and let you download a table for DNA mods

Wire wizard | Steam Engine | free vaping calculators

I just tried this. I didn't know about it. While a higher TC precision number is better, what is considered high? Mine is 500. That could be low if a high number is considered 4000.

 

[Beamslider]

The TC Precision number is basically a measure of how easily a Mod would be able to sense resistance change of the wire. A higher number should be a smoother Temp control on the wire. 500 should be a fairly reasonable number. You can use that calculator to play around with different gauge wire and coil wraps with the type of wire you like to try and improve the overall improvement. I don't think there is any hard set number other than higher is likely to work smoother than a lower number of TC precision

I use a Clapton SS coil. 26 AWG wrapped with 34 AWG and the TC Precision shows on wire wizard as 630. It works nicely in tc.

 

[ShowMeTwice]

I have eScribe, but it only works for my DNA mod, for Arctic Fox you need another program, which is Windows only (at least that’s how it was until a few months ago)

I just read the thread for the Mac "JAVA ported" vsn of AF ... there are issues folks are having. IMO it's not worth it. You are better off sticking to rebooting through Bootcamp into Windows (seamless + it just works). I use a Mac with eScribe + AF through a VM within Parallels Desktop with zero issues.

 

[m1ke]

I use a Clapton SS coil. 26 AWG wrapped with 34 AWG and the TC Precision shows on wire wizard as 630. It works nicely in tc.

I'm usin' a spaced twisted 32ga SS coil (0.57Ω) and it's decently consistent.

 

[Punk In Drublic]

TC Precision within Steam Engine is an attempt to describe how easily a device can sense the temperature of a coil (according to the developer)

It is a factor of TCR value of the metal x Resistance of the modeled coil x 1000000. The 1000000 has no value other than a filler to give a readable result.

The developer feels that lower resistance coils are more difficult to control via TC due to device limitations. Hence why T1 coils have a higher TC Precision score than Ni200 despite having a lower TCR value. I do not fully agree with this concept as the OP has demonstrated no problems with a Ni200 coil but problems with a SS316 coil. If using the same geometries, SS316 will always have a higher TC Precision score than Ni200 given it is naturally much higher in resistance. If your device has troubles reading low resistance coils that is a deficiency of the device, not the coil.

Truth is, the greater the increase in live resistance, the more your device has to work with. Live resistance also must fall within your set parameters under a typical vape environment (while you are taking a draw with saturated wick). If you have a 0.5 ohm SS316 coil at 25°C room temp, using a TCR value 0.00088 and a goal temp of 220°C – you need to ensure your resistance increases by +0.09 ohms or greater under a typical vape (draw with saturated wick) in order to meet that goal of 220°C. If your coil is influenced too greatly by air flow/saturation or you are not applying enough power, you may not be increasing that resistance by its needed amount and TC will not be function as it should resulting in dry burns.

This is where I personally feel programs such as Escribe and NFE Tools offer great benefits. You can view the live resistance and if that 0.5 ohm SS316 coil is only increasing by 0.08 ohms under a typical vape environment, then you can attempt at making adjustments to achieve that 220°C goal or adjust your final temperature accordingly.