eVic-VT mini?

[scaredmice]

Perfect, now try this if you dont mind,
At your base .12 fire at 220 or 230C for a good long 3 puffs and quickly off/on your unit and you should get a ohm increase iguest around .14 or .15.
Now select new coil when it ask for it when you press fire button.
Then lower the Temp say 150C to wards 400C and ouff away and tell me if its any diff compared to your earlier .12 base.
If you dont mind, do try to off/idle it for a while after this for about 5 to 10 minutes, and see if it could still fire at 150C to wards 400C and produce the same as before.

When you lock a coil (padlock present) and switch off the device, or take away the battery, and then you switch it on again the screen shows the actual resistance, regardless the padlock.....until you hit the firing button, when the actual, stored in memory resistance as base resistance is shown again.

I do not why, but if you're thinking that after the power off the base resistance has changed, you're utterly wrong, or at least that's how my unit behaves so far.

And naturally, if you re-calibrate the base resistance in that state of a bit more apparent base resistance because it is not at the allegedly 20ºC, but at 40 or 60 ºC, you're drifting away in that precise amount of temperature of the target, converting your anaemic vape in normal (or increasing the vapour production because the chip cuts off the power later, at higher temperatures).

If I understood you properly and my interpretation of what's happening is correct, You're the cause of your misbehaving mod.....check it again.

If not (whatever), please disregard me and accept my apologies. It’s really difficult to grasp your problems without a way of replicating them here.

 

[VapingTurtle]

The problems are going to boil down to either the accuracy of the VTC's resistance reading, or its TCR calculation, or both.

Oh, and btw, the TCR calculations are in the firmware, and since some are having problems and some are not, I would discount that factor.

Another factor could be the characteristics of the coil's material. (Not all Ni or Ti wires are the same, ya know.) But this has been tested with a wide variety of coils, so that's out.

So it is coming down (in my opinion) to the mod's accuracy of resistance recognition. Shoddy chip manufacturing tolerances or specifications would seem to be the culprit.

Maybe.

 

[Kaiser Bob]

When you lock a coil (padlock present) and switch off the device, or take away the battery, and then you switch it on again the screen shows the actual resistance, regardless the padlock.....until you hit the firing button, when the actual, stored in memory resistance as base resistance is shown again.

I do not why, but if you're thinking that after the power off the base resistance has changed, you're utterly wrong, or at least that's how my unit behaves so far.

And naturally, if you re-calibrate the base resistance in that state of a bit more apparent base resistance because it is not at the allegedly 20ºC, but at 40 or 60 ºC, you're drifting away in that precise amount of temperature of the target, converting your anaemic vape in normal (or increasing the vapour production because the chip cuts off the power later, at higher temperatures).

If I understood you properly and my interpretation of what's happening is correct, You're the cause of your misbehaving mod.....check it again.

If not (whatever), please disregard me and accept my apologies. It’s really difficult to grasp your problems without a way of replicating them here.

I can verify on my unit when the resistance drops after sleep it shows the lower value before during and after firing most times. I have seen the reading go up to the knitial locked value after hitting the fire button, but only once or twice.

Sent from my SAMSUNG-SM-N920A using Tapatalk

 

[eltaros]

When you lock a coil (padlock present) and switch off the device, or take away the battery, and then you switch it on again the screen shows the actual resistance, regardless the padlock.....until you hit the firing button, when the actual, stored in memory resistance as base resistance is shown again.

I do not why, but if you're thinking that after the power off the base resistance has changed, you're utterly wrong, or at least that's how my unit behaves so far.

And naturally, if you re-calibrate the base resistance in that state of a bit more apparent base resistance because it is not at the allegedly 20ºC, but at 40 or 60 ºC, you're drifting away in that precise amount of temperature of the target, converting your anaemic vape in normal (or increasing the vapour production because the chip cuts off the power later, at higher temperatures).

If I understood you properly and my interpretation of what's happening is correct, You're the cause of your misbehaving mod.....check it again.

If not (whatever), please disregard me and accept my apologies. It’s really difficult to grasp your problems without a way of replicating them here.

I'm not using the padlock because i could refill my subox mini without taking out the coils. I used it before because of my poor understanding of what the purpose is.
Your right, the base resistance has never changed after i off/on the unit, and it does show the actual resistance(which is higher because of the firing/warming prior to the off/on).
So does this means when i perform warmup/off then on /an choosing "new coil" would actually reset/recalibrate the base resistance?(because as per my understanding the onlyway stated in the manual is to have the tank removed while pushing the firebutton)-- i highly do think so because the "new" "old coil" message does popup on both cases.
And yes you are also right that if its indeed a reset of the base ohm this way it would make the TC not to work properly as the recomendation is to have it done at the room temp.

Im going through the manual again and it actually does make sence. So this could be my own wrongdoing.

But the fact remains,
I just get great tasty/dense vape as per my other mods by doing that and i dont burn out the coils or my cotton.

So the question is how could you have good vape at the base resistance set at room temp? EIther i have a faulty mod or just inproper setup as you mentioned.

Please i would greatly appreciate if you could share a sample of your setup so that i could replicate in mine.
Perhaps my ohm settings are just to low as per @Eitje mentioned (but i assume i could use it on my other TC mods as well as its on the given spec of this mod)

Here is mine.
0.15 and another at 0.08 ohm Nickel all set on room temp.(20C)
Subox mini tank.
Im set at 25W and trying hitting ;
--250F(doesnt produce any vape) all the way to 390F(a bit of vape but thin and not satisfactory)
--Hitting at 400F-450F does make the tank start cranking and vaper production is there but the taste is just abit throat hitting n plus if i do it long enough 5-6 moderade long puffs,
i would come to cotton burned hits. (my wicking is just not a problem at all, trust me)

Im building a more higher resistance coil now while waiting if you could share yours. (Anyone for that matter that have their vtc-mini working to their liking)
(note* with the same setup but this time using the warmup/off-on/new coil aka reset base and screwing the TC, butjust get nice vapes just as in my other TC mod, all around the board from 250F--400,420F with good thicker dense heavy vapour/taste/no cotton burns etc.. n i could repeat it for the rest of the day but with that anoying rest of the base resistance.)

 

[Eitje]

Perfect, now try this if you dont mind,
At your base .12 fire at 220 or 230C for a good long 3 puffs and quickly off/on your unit and you should get a ohm increase iguest around .14 or .15.
Now select new coil when it ask for it when you press fire button.
Then lower the Temp say 150C to wards 400C and ouff away and tell me if its any diff compared to your earlier .12 base.
If you dont mind, do try to off/idle it for a while after this for about 5 to 10 minutes, and see if it could still fire at 150C to wards 400C and produce the same as before.

I tried but I'm not getting anything much out of the unexpected. I can give it the new resistance whilst being hotter but that also behaves as expected. With the lowered temp, no vape and because the base resistance is now too high , it hardly vapes at all.

I can get the 0.12 to vape decently but I really need to bump up the temp for that , to around 280°c

 

[Eitje]

Mmmm.....I'm starting to doubt that too (your actual understanding of it...).

So far, neither Joyetech nor any user that I'm aware of, excepting you, has stated something like that. And surely Evolv and YiHi boards are not doing that (compensating somehow temperatures directly measured by the chip in its internals, if I understood you well).

All TC-enabled boards inherently trust your base setting, and link it to an ideal state of 20 ºC. It's up to you to put the atomizer at 20 ºC, or at least the mean temperature of the coil is expected to be 20ºC. But it is not so important if you drift away from 20ºC (inside certain boundaries). Any drifting will simply be added to the imprecisions and actual error of measurement of resistances.

Because of the drifting TCR's between firmwares and actual wires, the inherent tolerances in resistance measurements and the calibration at not exactly 20ºC, the expected errors could be as low as 3 ºC (5ºF, according to Evolv for the DNA40 and using Ni-200), but I think that's far too optimistic. My experience is that you can drift away as far as 20 - 25 ºC.

And here in Spain we are now at 20 - 28 ºC along the day.....

And when you compare chips, things go crazy quick enough to learn soon something: It's not about an exact temperature measurement and precision driving of the coil, it's about putting some limits to the heating process to avoid nasty by-products and dry-hits. It doesn't matter if you achieve that with "180 ºC" or with "260ºC" on the temperature setting.

If the precision of the measurement were of the utmost importance, Evolv and others would have chosen a termocouple-driven scheme, or a genuine Pt-10/100 near the coil, or something like that....but it's not and those designs are far more expensive and complicated. They just adapted what was nicely working (a good VW chip) to 'sense' temperatures and being driven by that input using the change of resistance of an also well known wire (the Ni-200 formerly know as 'non-resistive' wire for R-NR-R coils in ceramic setups).

Having said all that, and discarding as a faulty one your idea of chip compensating any temperature drifting, I continue without a real clue of what is happening to you guys. I'm a bit ashamed by the fact that my VTC mini is performing so nicely, just up to the moment I remember I paid for it, of course, and it runs as I was expecting, not more, not less.

No driftings on base resistance by any means, never, not one, it doesn't matter if I take out batteries, start/stop it, switch it on/off in this or that way, click on the power button with or without atty (or with a changed atty or not). No dry-hits, no anemic vape, unless I calibrate the base resistance wrong.

Always my fault if it happens, and always easily fixed just re-calibrating it in a proper mode....

Unless you put your device at sub zero temp when locking in, it shouldn't matter much. 20 or 33°c as base on the scale to let's say 250°c when firing, shouldn't have a major impact I suppose. The difference in resistance between 20-33 is very minimal ...

 

[Stig99]

Have been lurking reading posts.. and am in the same boat using a Subtank Plus with prebuilt NI coils when first recognised the mod says .16 and vapes fine at 420 but if sat for a while then show.11 (locked or not(previously at .16) and vapes crap.
Tried all the suggestions shown here sometimes work sometimes not.... no good.
I had bought previously pre built NI .2 coils from FT so rebuilt a stock Kanger coil head with this prebuilt coil. It is working great never loses the resistance even after rest changing batteries refilling atty works as it should so the question or thought that comes to mind is .2 or more fine below .2 no good.

 

[Jesse Wright]

Have been lurking reading posts.. and am in the same boat using a Subtank Plus with prebuilt NI coils when first recognised the mod says .16 and vapes fine at 420 but if sat for a while then show.11 (locked or not(previously at .16) and vapes crap.
Tried all the suggestions shown here sometimes work sometimes not.... no good.
I had bought previously pre built NI .2 coils from FT so rebuilt a stock Kanger coil head with this prebuilt coil. It is working great never loses the resistance even after rest changing batteries refilling atty works as it should so the question or thought that comes to mind is .2 or more fine below .2 no good.

This was my original thinking. Perhaps ti can only go >=.4 and ni >=.2 but it seems other users are having problems at any resistance... such as .35 not working but .4 does. I think this case was ni. Not sure though... perhaps these are the actual limitations, based on the stock heads that come w the ego mega. But I think one even mentioned that his stock coils presented the problem. I mentioned it earlier in this thread, but I was shot down pretty quickly by a few people who had come to this conclusion already, I suppose but cant be sure. Ordered mine still hasn't shipped yet. Also I believe some users were able to get their lower ohm builds working for a short amount of time.

 

[Tpat591]

This was my original thinking. Perhaps ti can only go >=.4 and ni >=.2 but it seems other users are having problems at any resistance... such as .35 not working but .4 does. I think this case was ni. Not sure though... perhaps these are the actual limitations, based on the stock heads that come w the ego mega. But I think one even mentioned that his stock coils presented the problem. I mentioned it earlier in this thread, but I was shot down pretty quickly by a few people who had come to this conclusion already, I suppose but cant be sure. Ordered mine still hasn't shipped yet.

They were stock CLR coils and I think he was rebuilding them himself.

 

[Jesse Wright]

They were stock CLR coils and I think he was rebuilding them himself.

Ah. I thought it was the CL that came w the tank. That could explain that. Well I'll suggest it again. Build above.2 for ni and above .4 for ti and see what happens for the users experiencing these problems. The ones that aren't, do you have builds under these specs that work just fine?

 

[Tpat591]

I still thing all these symptoms, serial & batch numbers, symptoms and theories belong in a dedicated thread so these issues are not cluttered with non relevant posts so Joyetech can review them easily in a correction effort they may undertake in future.

I have all three colors of the full kit from Ecig.com because I was so impressed with kit and price and all are working as expected with stock coils.

 

[scaredmice]

I'm not using the padlock because i could refill my subox mini without taking out the coils. I used it before because of my poor understanding of what the purpose is.
Your right, the base resistance has never changed after i off/on the unit, and it does show the actual resistance(which is higher because of the firing/warming prior to the off/on).
So does this means when i perform warmup/off then on /an choosing "new coil" would actually reset/recalibrate the base resistance?(because as per my understanding the onlyway stated in the manual is to have the tank removed while pushing the firebutton)-- i highly do think so because the "new" "old coil" message does popup on both cases.
And yes you are also right that if its indeed a reset of the base ohm this way it would make the TC not to work properly as the recomendation is to have it done at the room temp.

Im going through the manual again and it actually does make sence. So this could be my own wrongdoing.

But the fact remains,
I just get great tasty/dense vape as per my other mods by doing that and i dont burn out the coils or my cotton.

So the question is how could you have good vape at the base resistance set at room temp? EIther i have a faulty mod or just inproper setup as you mentioned.

Please i would greatly appreciate if you could share a sample of your setup so that i could replicate in mine.
Perhaps my ohm settings are just to low as per @Eitje mentioned (but i assume i could use it on my other TC mods as well as its on the given spec of this mod)

Here is mine.
0.15 and another at 0.08 ohm Nickel all set on room temp.(20C)
Subox mini tank.
Im set at 25W and trying hitting ;
--250F(doesnt produce any vape) all the way to 390F(a bit of vape but thin and not satisfactory)
--Hitting at 400F-450F does make the tank start cranking and vaper production is there but the taste is just abit throat hitting n plus if i do it long enough 5-6 moderade long puffs,
i would come to cotton burned hits. (my wicking is just not a problem at all, trust me)

Im building a more higher resistance coil now while waiting if you could share yours. (Anyone for that matter that have their vtc-mini working to their liking)
(note* with the same setup but this time using the warmup/off-on/new coil aka reset base and screwing the TC, butjust get nice vapes just as in my other TC mod, all around the board from 250F--400,420F with good thicker dense heavy vapour/taste/no cotton burns etc.. n i could repeat it for the rest of the day but with that anoying rest of the base resistance.)

O.K., let's do it step by step....

Firstly, if you see the 'new coil/same coil" (a.k.a. NCSC....from now on....) message and you positively know that it's the same coil...why do you answer as 'NewCoil'? Because you've seen an apparent change in resistance? If so, that's a poor interface design as it forces some of you to the wrong choice, but knowing now that the actual base resistance is unchanged (if it is, like my device does), now you're in best position to pick up the right answer.....

Secondly, about some setups....currently I'm with a Magma in single coil, Ni-200 0,40 mm, and it's locked at 0,17 ohm. I've put 210 ºC as target temperature, a bit lower than I usually choose, and that 0,17 ohm resistance goes up to 0,34 ohm.....

Remember, that's a ratio of resistances, R/R0=2,000, which is found under TCR=0,00575 at 190-195ºC. but the actual TCR for Ni-200 in this mod is about 0,0055, so under that one, it's really about 200-205ºC, which I sanction as close enough.

If I do the same in a IPV D2 (I've got one too, for that matter), and I maintain the 210 ºC target, it goes up, nearly burning my vape. Why? because my IPV D2 seems to use a TCR of about 0,0065 or more, so it expects a ratio of 2,2 or more....and as the actual Ni-200 has not so high TCR, the actual temperature is about 255 ºC...... check the tables (or do the math with the equations) and you'll see that.

Now your issue. You firstly set the base resistance as 0,15 ohm at, supposedly, 20ºC. You try it at a unknown temperature setting (whatever) and you find it unsatisfactory or anaemic...... then you re-set the base resistance, but now your atomizer IS NOT a 20 ºc, it is hotter, and without changing your temperature setting, now it apparently works better.

It's not an issue of random variances on base resistances, TCR's or software driftings. It's you, changing the calibration at a wrong temperature. As a matter of fact, if you commit some error in the actual temperature of calibration, let's say 'deltaT' (being it higher than the expected 20 ºC), your actual maximum temperature and the one set up on the screen will differ one another in 'deltaT'....Why? Because of the linear nature of the approximation that the chip uses.

So, if you re-calibrate at 60 ºC instead of the expected 20 ºC, you target temperature will be effectively 40ºC hotter...and naturally that causes a warmer vape. Try to calibrate it properly and then set the target 40 ºC hotter instead.....it should work the same, and it appears to me more logically consistent, doesn't it?

Sorry for the long and numerically linked answer, but it was as important the why as the short answer should be. And the short answer to 'So does this means when i perform warmup/off then on /an choosing "new coil" would actually reset/recalibrate the base resistance?' is YES. You're re-calibrating (wrongly re-calibrating) the device.

But if, coupled with this, there are other issues, whereas numerical, precision, stability of calibrations, user-induced because unexplained behaviours, or what else close encounters on the third phase you might find there, well, it's all up to discover what's really happening........

 

[Stig99]

deleted

 

[Max0819]

I think you're making that up.
And reading too much into it.
And scrutinizing factors that don't really apply.

Certainly possible, I am a bit OCD and have been known to think too deeply.

Max

 

[mc8]

Oh, and btw, the TCR calculations are in the firmware, and since some are having problems and some are not, I would discount that factor.

Another factor could be the characteristics of the coil's material. (Not all Ni or Ti wires are the same, ya know.) But this has been tested with a wide variety of coils, so that's out.

So it is coming down (in my opinion) to the mod's accuracy of resistance recognition. Shoddy chip manufacturing tolerances or specifications would seem to be the culprit.

Maybe.

My mini and full size show same resistance. At least joyetech is being constant at getting it wrong
My issue is just that i have to set my mini at 290'C for the same vape as i have at 220'C with full sized one. It actually isn't a big thing, i just don't like seeing that 290 on that display

Couldn't that be wrong TCR calculations?

 

[Fullknight]

I just took the KF 0.12Ω Ni200 off my Smy mini and put it on my Evic VTC Mini lowered temp to 420F and it works perfect. Even after going to sleep for a while. I put the Ego one Mega tank with stock Ti coil 0.43Ω on the Smy mini and it works perfect on it?


Sent from my iPhone using Tapatalk

 

[Tpat591]

My mini and full size show same resistance. At least joyetech is being constant at getting it wrong
My issue is just that i have to set my mini at 290'C for the same vape as i have at 220'C with full sized one. It actually isn't a big thing, i just don't like seeing that 290 on that display

Couldn't that be wrong TCR calculations?

Joyetech got a lot of bad publicity on the VT with guys doing dry burn tests and the cotton bursting into flames. They completely redesigned their temperature control heuristics in the VTC Mini to correct inaccuracies present in the VT Series that they were highly criticized for and by most accounts erred on the side of caution slightly on the low side this time around. A disagreement between the VT and the VTC is to be expected!

 

[Carnage9270]

I heard that with the SMOK M80, but not the Evic.

 

[Tpat591]

Few videos on Youtube showing it in action. I'll spare you the link because most of those tests are tedious and many of them I consider somewhat slanted. If you really fell the need, I'm sure you can find them.

 

[Jim_ MDP]

But it still wouldn't explain the change to "anemic vape" on wake from sleep.