Divine Tribe atty's

[OF]

And finally... regarding TCR rates for donuts being straight or curved, IDK really, but from what I observed over alot of v2.5 bases, the Ω rise to achieve the same effects tended to be alot more on a high Ω base as opposed to a low Ω base. The high ones like 0.82 needed at least 0.33-0.36 rise to make the vape I liked. The low ones, like 0.68Ω, could rise as little as 0.29-0.32 to make vape that I like. I even got a couple flukishly low Ω bases like 0.55, 0.60Ω, that would only need to rise 0.15-0.20 to make my warmth with TCR 245!

So maybe if the rate is linear, maybe the slope of the line is different for different base Ω?

And maybe the rates are not perfectley linear, because of the heat transfer between metal to ceramic? IDK really but I'm just reading what all you guys are saying and trying to make sense

Careful here, TCR is based on the temperature of the heater, not the doughnut. It senses the metal, not the ceramic (which is sure to be cooler by Thermodynamics). That loss (heat wise) is going to change with temperature, no doubt being more at first (until the rest of the atty warms up, conduction will be greater) and radiation plays a bigger role as temperatures rise.

It's important, I think, to not keep thinking in terms of XX Ohms rise when trying to understand how TCR is used. It's not the absolute change in Ohms, but the relative change in percent. Two V3 attys at say .44 Ohms that go to .66 each have a rise of .22 Ohms. Put them in series and you have .88 Ohms going to 1.32? A rise of .44 Ohms. Twice the absolute value rise, but still the same percentage. Look at the formula for calculating the values in the reference I posted above, it's all based on ratios. A higher cold resistance means a higher increase for the same temperature rise measured in Ohms.

Yes, the slope of the line in such tings can and does change, but it remains a straight line. Linear. It's the way metals work generally. In the classic linear equation (y=ax+b) "a" is that slope (expressed in trig terms). To be specific, Tangent (or Cot depending on your perspective). What carpenters and Civil Engineers call 'rise over run' in their trades. Positive numbers rise going left to right, negative ones go down. Bigger absolute values are steeper rising or falling. But still a straight line (linear). In our case there is on 'b" (actually b is zero) since there is no offset (changes are relative).

If you want something non linear, like say how bright the sun is on different planets, you need 'second or higher order factors'. in this case, since light on a distant planet will depend on the SQUARE of the distance (light spreads 'two ways' as it expands out) and we start to drift into calculus and all that icky stuff with stuff like y=ax^2+bx+c and stuff sure to bore the guys in the cheap seats to tears.

At some point, past getting enough tools to control stuff, I think it's best enjoy the unit and not stress on technical terms. For myself I'm pretty confident I understand this, I've used and taught it for a lot of years. For instance, that's the standard way of measuring how hot transformer or motor windings get in use. You measure the change in resistance (cold to hot), convert to PPM (or percent), divide by the 'book number' for Copper and get degrees rise. You need to use relative change, not absolute.

Regards,

OF

 

[tharealmclovin]

Where is the best place to get an authentic VTC mini? No need for rush shipping.

 

[whatavape]

And finally... regarding TCR rates for donuts being straight or curved, IDK really, but from what I observed over alot of v2.5 bases, the Ω rise to achieve the same effects tended to be alot more on a high Ω base as opposed to a low Ω base. The high ones like 0.82 needed at least 0.33-0.36 rise to make the vape I liked. The low ones, like 0.68Ω, could rise as little as 0.29-0.32 to make vape that I like. I even got a couple flukishly low Ω bases like 0.55, 0.60Ω, that would only need to rise 0.15-0.20 to make my warmth with TCR 245!

So maybe if the rate is linear, maybe the slope of the line is different for different base Ω?

And maybe the rates are not perfectley linear, because of the heat transfer between metal to ceramic? IDK really but I'm just reading what all you guys are saying and trying to make sense

Careful here, TCR is based on the temperature of the heater, not the doughnut. It senses the metal, not the ceramic (which is sure to be cooler by Thermodynamics). That loss (heat wise) is going to change with temperature, no doubt being more at first (until the rest of the atty warms up, conduction will be greater) and radiation plays a bigger role as temperatures rise.

It's important, I think, to not keep thinking in terms of XX Ohms rise when trying to understand how TCR is used. It's not the absolute change in Ohms, but the relative change in percent. Two V3 attys at say .44 Ohms that go to .66 each have a rise of .22 Ohms. Put them in series and you have .88 Ohms going to 1.32? A rise of .44 Ohms. Twice the absolute value rise, but still the same percentage. Look at the formula for calculating the values in the reference I posted above, it's all based on ratios. A higher cold resistance means a higher increase for the same temperature rise measured in Ohms.

Yes, the slope of the line in such tings can and does change, but it remains a straight line. Linear.

You're both using the same equation, here!

dR = TCR*R0*dT

(dR = change in resistance, TCR = the temp-resistance coefficient for the material - 99% alumina is 1.76*10^-3 [K]^-1, R0 = cold resistance of coil, and dT = temp change)

So, yes, dR is different for each coil - but dR/R0 is constant across all of our coils, since the TCR is (mostly) constant at operating temperatures (for ceramics, <500C is always stable), and we are hoping for the same dT.
If you want to use resistance to measure your temperature, you need to take into account the cold resistance, too. I'm now on my second donut, which has a higher R0 and thus a higher resistance change - I am running this one up to .72 ohms, vs .63 for my first donut. The leads on this one may be a bit longer. The plot thickens!

Edit: TCR can also be expressed as 1760 PPM for alumina -- anyone tried 175?
Edit edit: dyslexia isn't fun... TCR, not TRC.

 

[OF]

You're both using the same equation, here!

dR = TCR*R0*dT

(dR = change in resistance, TCR = the temp-resistance coefficient for the material - 99% alumina is 1.76*10^-3 [K]^-1, R0 = cold resistance of coil, and dT = temp change)

So, yes, dR is different for each coil - but dR/R0 is constant across all of our coils, since the TCR is (mostly) constant at operating temperatures (for ceramics, <500C is always stable), and we are hoping for the same dT.

That's sure not the formula I'm using. Nor does it 'look right' to me, can't say why, maybe I'm just not looking at it right. I'll stick with the classic formula in the link I posted (and other places), which gives final (target) resistance. The final resistance is the original resistance times the sum of one and the change in temperature times the constant.

I'm also sure that alumina has nothing to do with the TCR technique here. Alumina is an excellent insulator, it just doesn't conduct a significant current under any conditions we're dealing with. The exact same things happen with bare wire (no ceramics at all), right?

I think it's a lucky break that the M value seems to be 'the same'. It was, of course, always a compromise. The real TCR for the heater is no doubt bigger than we give it credit for. There are some hopefully small and hopefully stable resistances in series. Like the connector in the V3, the posts, the leads to the heater itself, the Silver braze we're told attaches them to the film itself. The Mod has no way to sense or deal with this separately, it has to be 'cooked into' the M value we feed it. More, the leads keep some part of the film from getting as hot. Notice when you do overheat it to glowing you get two curved bars, with cooler ends where the leads come in? That material is not as hot so it's not 'contributing it's fair share' to the total rise in resistance. This is compensated for with the experimental value used to set the M value. Perhaps the bigger doughnut is simply scaled up using the same material so the TCR value 'tracks'.

However you get there, you should consider the change in resistance as a part of the original, in percent, PPM or 10^-5 for the "Mod system"? Not the absolute value in Ohms, but that value multiplied by the magic number and ADDED to the original to get the target. That's what TCR control is based on?

Or put the numbers in, trust the machine, and change them to get the results you want........... IMO you buy vapes to enjoy, not as an exercise in Physics.

OF

 

[WKONE]

FINALLY GOT MY V3! (and the 2.7 I ordered 2 days before the V3 release )

Loving the hits of Blue Cheese shatter on this. I put down about a 0.2 and the wife and I are pretty blazed.

Settings on my eVIC Vtwo Mini are:
TCR M1 120
22.5w @ 450F

Using the the below post as a starting point, I found that the airflow was really cooling the donut down at 380F, and I was getting barely anything but ghost hits. After bumping up wattage to 22.5 and experimenting with temps up to 450, I am now getting nice tasty vapes.

=========== Memoirs ================

My settings tonight, I was pleasantly surprised:
Wattage for TC mode: 17.0 watts
TCR M1 = 120
Target temp: 380 deg F
Temp measured at donut 340-390 deg F

For a Target temp of 550 deg F
Temp measured at donut 520-560 deg F

When would anyone use a higher temp setting than e.g. 450?
If your air flow quickly cools the donut/oil.

 

[clearlight]

So what's up with the colored v3's on the site? When will those be available? And will black be available?

if you're referring to this, it is merely a diagram. For the other colors @divinetribe said

"
i have black coming oct 10 i am working on all the colors not sure when they will come to fruition..
"

 

[Quote]

Where is the best place to get an authentic VTC mini? No need for rush shipping.

I got mine on eBay. Usually free shipping and no tax. Make sure you're buying from the US, shipping from China can take significantly longer and they're not much cheaper.

 

[whatavape]

That's sure not the formula I'm using. Nor does it 'look right' to me, can't say why, maybe I'm just not looking at it right. I'll stick with the classic formula in the link I posted (and other places), which gives final (target) resistance. The final resistance is the original resistance times the sum of one and the change in temperature times the constant.

I'm also sure that alumina has nothing to do with the TCR technique here. Alumina is an excellent insulator, it just doesn't conduct a significant current under any conditions we're dealing with. The exact same things happen with bare wire (no ceramics at all), right?

A short derivation might help:

dR = TCR*R0*dT (my formula)

Rt - R0 = TCR*R0*dT (Rt is final, or target, resistance)

Rt/R0 - 1 = TRC*dT

Rt/R0 = 1 + TRC*dT

Rt = R0* (1 + TRC*dT) (your formula)

We are all on the same page, just as if we reading in a different language. There are a million ways to simplify an equation, which can drive you nuts... Physics will do that to you!

And yes, it's true that alumina doesn't conduct, nor is it the conducting mass in our donut. However, it is transferring the heat to our materials after receiving the heat from the wire embedded inside. It is relatively accurate to approximate the "coil" then as being made of alumina, since the resistance (of the actual coil) rises with temperature. The TCR value for the actual coil is likely in the low 200s, which may explain why I saw earlier that TCR 190 seemed to work well (in the middle of the two, since the "coil" would have an ideal TCR of 176). I think we will find that everything we can try is an "approximation at best," but it is extremely helpful to compare our estimates and measured outcomes. That is how we improve our technique!

It may not be "conventional" to model a change in resistance of an insulator, but it has proven to be a useful approximation, at least to me, given my circumstances (no TC mods).

........... IMO you buy vapes to enjoy, not as an exercise in Physics.

OF

PS: For me at least, the exercise in Physics IS the part to enjoy! I'm enjoying the challenge of dialing this thing in on a VW mod, one that's small and convenient to carry with my V3, and since it's working well enough, no need to be hasteful in replacing with a TC mod!

 

[fernand]

@Vape Donkey 650 and @OF, brethren and all, there are very separate issues here.

1 - the more important one to most, is how best to use the various "donut" (resistance-wire-in-ceramic) heaters to vape concentrates. Getting the best/most out of the concentrates.​

2 - The other issue, that hopefully doesn't turn off the #1 seekers, is that we're nearing a chance to really control the vaporization temperatures on an inexpensive rig, and this isn't as simple as we'd like. So the nerds in the herd may be getting absurd, but we're trying to figure it out. Please forgive !​

On issue #2, can we agree that what we want to control is the temperature that the oil is bubbling at? Temp will never be identical across the donut, and the donut-oil interface isn't ideal either. But let's pretend it is for now.

In TC mode the temp display is used to set the desired temp. That's the only time it's real. The rest of the time it's an output of the firmware, calculated from the TCR we feed it and the heater behavior. It cannot be used to calculate anything because it's what it THINKS the temp should be. It's not a measurement. We can't plug it into any calculation, say to derive the donut's TCR, as that would be circular.

Because we have no idea of the alloy used in the winding (which would directly give us a TCR value), we desperately need a measurement of the actual hot donut temperature so we can either calculate, or successively approximate (cut & try), a TCR.

AFTER we manage to calibrate the whole chain by feeding it a TCR and confirming regulated temp, we can get to where the temp we requested is what is shown and maintained when it hits "protection".


@Vape Donkey 650 if you can't set emissivity on your IR Thermometer you could possibly try to scale your reading or place a coating on the ceramic. At a default e = 0.95 the reading isn't very meaningful regardless of how the "barrel" lines up. Someone here might know how to scale your reading, I don't.

I spent desperate times struggling with thermocouples and was happy when I found that on average with e = 0.50 the thermocouple and my IR gun temp readings on clean white donuts were close enough to sort of trust.

Whatever you think of the 0.50, whether the IR gun then reads 100% accurately, the big difference I've seen between the V2.x and the V3 is that with the V3 if I set the eVic to say 380 deg F and TCR = 120 I read ~ 380 on my IR gun. To get that match on the two V2s that I have, I have to set TCR = 220 on one and 230 on the other. These V3s really are different.

Coming back to #1 , it seems that it takes a hotter V3 to give a good vape. I can only guess that it's because of the massive air cooling. Is it that the mod can't keep up? Or the inner wire is kept hot but the oil on the ceramic isn't?

Sorry about the long posts, I'm trying to be as clear as I can within limits, maybe that comes off wrong.

 

[WKONE]

Coming back to #1 , it seems that it takes a hotter V3 to give a good vape. I can only guess that it's because of the massive air cooling. Is it that the mod can't keep up? Or the inner wire is kept hot but the oil on the ceramic isn't?

Agreed, my settings for a good vape are higher than most recommended settings (see above).

 

[whatavape]

On issue #2, can we agree that what we want to control is the temperature that the oil is bubbling at? Temp will never be identical across the donut, and the donut-oil interface isn't ideal either. But let's pretend it is for now.

That's the ticket! If only we knew what material was used for the coil! In reality, the best we can get is an estimate, with all of the tools we use and their inherent error. Spend a while studying error analysis and you'll realize nothing is really worth measuring after all...

@Vape Donkey 650 if you can't set emissivity on your IR Thermometer you could possibly try to scale your reading or place a coating on the ceramic. At a default e = 0.95 the reading isn't very meaningful regardless of how the "barrel" lines up. Someone here might know how to scale your reading, I don't.

I spent desperate times struggling with thermocouples and was happy when I found that on average with e = 0.50 the thermocouple and my IR gun temp readings on clean white donuts were close enough to sort of trust.


Whatever you think of the 0.50, whether the IR gun then reads 100% accurately, the big difference I've seen between the V2.x and the V3 is that with the V3 if I set the eVic to say 380 deg F and TCR = 120 I read ~ 380 on my IR gun. To get that match on the two V2s that I have, I have to set TCR = 220 on one and 230 on the other. These V3s really are different.

If we assume that Alumina is the material, then emissivity should be set to 0.6-0.8, as this is the range for alumina, depending on the porosity. You may achieve closer measurements with yours set to 0.5 than having it set at stock (0.95), and since the thermocouple agrees, that's probably a decent enough setting. As far as scaling goes... it's much more effective and much easier to spend the few extra bucks on an IR thermometer with a variable setting, but if you (or @Vape Donkey 650) want to know how to scale it, PM me and I'll see how well I can explain it (depends on how medicated I am...)

I definitely think airflow is a primo factor here, since the TCR settings everyone is using are an educated guess, with tweaking at best. Because, at least on my two v3's, airflow is crazy compared to the v2.7's I've used. The v2.7's are much more restricted, so they will stay closer to target temp. Overshooting (setting a higher target temp) may help with v3's, since the cooling is so extreme. TCR is important, but what the mod is really regulating here is the resistance, aiming for a target resistance based on what TCR setting you tell it. The TCR is just a scaling factor, and I think you hit the nail on the head - the best way to figure it out is to keep testing!

 

[fernand]

@whatavape oh yes, the V2 is very different in that the erl can simmer at a steady temp and the air swoops in from above. It's more economical and focused. The V2-alikes with the air holes higher up and an alumina cup insert are my favorites, even temps and tiny amounts are effective. The V3 is more brute force, fer sure, but I guess if people are dabbing big chunks, it's the way to go. That or a Titanium nail, carb cap and all

 

[StickyShisha2]

i had been hoping v3 worked like v2. Too bad, v3 has drain holes in the bottom of the cup under the donut, so if the temp doesn't climb fast enough, the entire load melts and drains down under the cup.

 

[nikcorda]

@whatavape oh yes, the V2 is very different in that the erl can simmer at a steady temp and the air swoops in from above. It's more economical and focused. The V2-alikes with the air holes higher up and an alumina cup insert are my favorites, even temps and tiny amounts are effective.

still trying to find one of these V2-alikes, as i really want to use the alumina cups, but no luck finding any

the V3 is very tempting at the reduced price, but i take baby dabs, and pretty much require the alumina cup setup for my personal preference

 

[Quote]

i had been hoping v3 worked like v2. Too bad, v3 has drain holes in the bottom of the cup under the donut, so if the temp doesn't climb fast enough, the entire load melts and drains down under the cup.

That's why the instructions say to inhale as soon as you start pressing the button. Start your inhale slow to give it time to heat up, and speed up once the screen says temp protection.

 

[insideoutman]

Where is the best place to get an authentic VTC mini? No need for rush shipping.

i got ripped from ebay sellers in the past.
I have had great success with eciggity i think is the one... they are based in hawaii though, but their shipping was phenominal in those two orders.



WOWW~!

thanks matt @divinetribe . and thanks @Vape Donkey 650 , @fernand , @OF .. unbelieveable vape I just had on this V3 DT !

..using the VTCmini w/ TCR 190, 21W, 380ºF.... thanks. right out of the gate, you guys cracked the code lol. reminds me of the documentary i just watched about compaq trying to crack IBMs code. ha

vape on my friends
and may we continue this open source investigation

 

[WKONE]

Some nice Girl Scout Cookies CO2 shatter on a fresh donut! #DonutPrawn

 

[tharealmclovin]

Got my V3. Are we using the same settings? Tcr245? I'm seeing others posted.

 

[fernand]

@nikcorda Try a search like this, I can see many.

http://www.ebay.com/sch/i.html?_fro...eramic+donut.TRS1&_nkw=ceramic+donut&_sacat=0

One vendor that has always delivered and very fast was this one.

I don't think any of the V2-alikes have as good or consistent a heater as Matt's. And I got one that required a lower TCR than the usual 160-180. But if I'm using a cup, it doesn't matter if the filament isn't as smoothly distributed.

Important detail: if using a 6.8 mm x 4 mm cup, it sits in the well with very little play, and that works great. But after a session it settles in even better and often sticks. It can get very hard to extract. To remove it, just heat it up and tap on the mod, and it drops right out.

This technique works with oils, shatter, wax, anything that melts down. Best results with a slow draw. Of course if you crank the temp up you can suck up fat clouds, but it's going to spatter and make a mess, and for that you may as well just dump erl directly on the burner or go with a 3.0.

I haven't tried this yet, but in the lab when something's boiling with bursts and spatter, you drop in what's called a boiling stone, a small very porous piece of ceramic. That focuses the bubbling on the stone and limits sputtering. I wonder if this trick could be used to smooth out evaporation.

 

[Steven]

@divinetribe besides the magnets or o rings to replace the screws, do you think it's possible to put some silicon bushings of some sort in the holes where the leads go through the cup? I tried to make some myself by it is too small for me to work with. I ask because it seems the only leaks appear to leak through the holes where the leads are going through. I think silicon bushings should keep a decent seal. If that's not possible because the holes are too small, it's something to maybe implement in future models. Like maybe make bigger lead holes in the cup so they can be fitted with silicon bushings? Just my 2 cents

Got a new way of loading the v3. So if you are familiar with rolling your shatter into a ball and loading it that way, this will be easy. I roll up a ball of shatter about the size of a bb (could be bigger than the bb size for v2). Then I drop the ball onto one side if the donut. I click the power enough to have the ball stick to the donut. After, I tilt the mod horizontal and rotate slowly as I gently press the power, melting the shatter ball and spreading it evenly over the entire donut.

 

[Silat]

rolling your shatter into a ball and loading it that way, this will be easy. I roll up a ball of shatter about the size of a bb

I hate the flavor of flesh in my dab.

 

[Steven]

I hate the flavor of flesh in my dab.

Oh are you talking about because I touch the wax with my fingers? I heard there are many who don't like to contaminate wax by touching. U can taste it? Either way, method can b used by placing a chunk too

 

[Silat]

Oh are you talking about because I touch the wax with my fingers? I heard there are many who don't like to contaminate wax by touching. U can taste it? Either way, method can b used by placing a chunk too

I was trying to be funny with a bit of added truth.

 

[Steven]

I was trying to be funny with a bit of added truth.

Ahhh I thot so. Was actually a bit curious if anyone can actually taste it? Some people got some super buds. Personally I tend to not bug out on things like this but I'm not everyone

 

[Bad Ocelot]

I haven't tried this yet, but in the lab when something's boiling with bursts and spatter, you drop in what's called a boiling stone, a small very porous piece of ceramic. That focuses the bubbling on the stone and limits sputtering. I wonder if this trick could be used to smooth out evaporation.

Perhaps one of w9's black ceramic wicks? I've got a few of those, planning on testing them out in the 2.5/7. They appear to be too small for the 3.0.