TC and MTL

[Tubbyengineer]

As @Mr Numpty says, you are letting previous experience with wattage mode cloud your thinking, TC is a whole different way of approaching your vape. Forget about Sub Ohm or MTL rules that you are used to. For Wattage mode based vaping you tend to build at lower resistances for Subohm because you'll need the HIgh power to get a warm vape with the high airfow, and for MTL vaping you build Higher ohms at lower powers because you want the quick warm up but need to use lower power to prevent burning with the lower airflow involved. TC does away with the neccessity to build in that manner because it will never overheat - instead you build TC setups at the recommended resistances - They're in the DNA Datasheets but for most people using DNA 75's then over 0.15 ohms for Ni200 or NiFe30, and over 0.25 Ohms for SS316 and Ti01 are good targets to aim for. Once you've built your coil, registered the starting resistance and locked it then it won't matter too much whether you're using an MTL or DTL atty. I tend to run at about 425f with a preheat of 75w and power set to 40-50w regardless of what tank I'm using (I use those settings for A Heron V2, A Rose V3 and a Kayfun V5) and get pretty much exactly the same results on all three.

 

[danb]

I don't even bother with a pre-heat setting, I never saw the point - for me the set wattage is already a preheat before the chip starts regulating down the output.

As above, there is not a great deal to worry about with power and resistance in TC mode. You just need enough resistance (check tables or the "TC precision" value of your build on Steam Engine) and enough power to reach the set temp quickly but without overshooting (Escribe device monitor or trial and error).

My Kayfun mini V3 is set up with 6 wraps of 28g Stealthvape NiFe30, 2.5 mm ID, 0.17 Ohm, 20W limit, ~220 C

 

[Dorset]

Getting there - slowly. Tried builds of 9,8,7,6 wraps of 0.35 SS316L. That gives .9 to .61Ohms. They all work - stable vape and temp control. However at .9Ohms the set temp is 210 for a 'just warm vape'. At .6Ohms its 250 degrees. Any ideas why?

I know enough about Thermodynamics to not try and figure out whats going on - my gut feeling is that the more wraps or greater surface area there is will give better heat transfer from the coil to juice.

I will try a 0.5R build ( that's what Evolv recommend) - however need some heavier guage SS wire - are Stealthvape still going? Looks like I'll have to try Crazy Wire Co.

Nb. Tried two tanks - Siren 22 and a Corolla 1.5. It's the coil build - not the mod. Repeated each buld - same results each time.

 

[speedfreek67]

are Stealthvape still going? Looks like I'll have to try Crazy Wire Co.

Yup Stealthvape are still going, ordered some wire (Ni200) from them over the weekend, dispatched today.

 

[danb]

. However at .9Ohms the set temp is 210 for a 'just warm vape'. At .6Ohms its 250 degrees. Any ideas why?
.

My theory:

More wraps = smaller intercoil distance (less spacing)
Less spacing = less even heating (centre of the coil gets hotter than the ends, a microcoil is the extreme example).

The mod calculates the average temp of the coil, but it can't tell if the heating is even or not. So the more even the heating (i.e. The wider the spacing) the closer the calculated temp is to the real temp. With lots of wraps the centre of the coil is probably significantly hotter than the average coil temp, hence why you end up finding a sweet spot at lower set temp. Does that sound reasonable?

 

[Mr Numpty]

Getting there - slowly. Tried builds of 9,8,7,6 wraps of 0.35 SS316L. That gives .9 to .61Ohms. They all work - stable vape and temp control. However at .9Ohms the set temp is 210 for a 'just warm vape'. At .6Ohms its 250 degrees. Any ideas why?

I know enough about Thermodynamics to not try and figure out whats going on - my gut feeling is that the more wraps or greater surface area there is will give better heat transfer from the coil to juice.

I will try a 0.5R build ( that's what Evolv recommend) - however need some heavier guage SS wire - are Stealthvape still going? Looks like I'll have to try Crazy Wire Co.

Nb. Tried two tanks - Siren 22 and a Corolla 1.5. It's the coil build - not the mod. Repeated each buld - same results each time.

Do yourself a favour and get some Stealthvape NiFe30 (28 gauge for single coils). You'll see a big step up in the consistency of vape that TC has to offer, particularly over 316L.

 

[speedfreek67]

Hi, sorry if I am hijacking the thread here, but seeing as I am an MTL vaper I thought I would ask my question in this thread, rather than starting a new one.

I am trying out temperature control for the first time this evening and have a noob question.

I built an Ni200 29awg coil that came out at 0.21 ohms and have put it in my Unity Dripper. Everything seems to be working okay (locked the resistance at room temperature), but I am unsure as to how high a temperature I can push this to. Do I risk burning the cotton if I set the temp too high? I know dry cotton burns at around 420F, so if I set the temp to say, 450F, and the cotton dried out due to chain vaping, would that temperature allow the cotton to burn?

Basically, what are the practical limits of temp control?

The vape seems a little weak at 50W and 420F, which is why I am asking.

 

[Mr Numpty]

Hi, sorry if I am hijacking the thread here, but seeing as I am an MTL vaper I thought I would ask my question in this thread, rather than starting a new one.

I am trying out temperature control for the first time this evening and have a noob question.

I built an Ni200 29awg coil that came out at 0.21 ohms and have put it in my Unity Dripper. Everything seems to be working okay (locked the resistance at room temperature), but I am unsure as to how high a temperature I can push this to. Do I risk burning the cotton if I set the temp too high? I know dry cotton burns at around 420F, so if I set the temp to say, 450F, and the cotton dried out due to chain vaping, would that temperature allow the cotton to burn?

Basically, what are the practical limits of temp control?

The vape seems a little weak at 50W and 420F, which is why I am asking.

The cotton shouldn't burn whatever you set the temp to. If it is dry, temp control will kick in quickly and it just won't vape, so feel free to bump it up until you find the vape you want.

 

[Dorset]

Almost there - 8 wraps of 26awg SS316L comes out at 0.61Ohms. Easy to wick and clean, wire a bit thick i.e. can be difficult to trap under the post screws. But can be burnt to clean and to remove hot spots.
Got some NiFe30 from Stealthvape - 29awg - should have got 28awg. 10 wraps comes out at 0.36Ohm. The first coil - managed to burn it when getting rid of hot spots and coils shorting etc - tasted foul. Second one - spaced and not cleaned/overheated. Had to 'adjust it' to get rid of a short when the resistance dropped from 0.36 to 0.29Ohms. The wire is thin - and springy - pulling cotton through can bugger up the spacing. Any advice on building spaced coils with thin wire?

Whats the best way to clean a Nify coil? I'd prefer to avoid having to wrap a new coil each time the cotton is replaced.

 

[shale84]

For TC builds cotton should be looser than for MTL builds,so put less cotton and make it fluffier,for cleaning be careful cos I read that some tipes of wires can't be dryburned cos they release some toxic things on high temps