Having to run DNA75 ~100F hotter than I should

[tux]

Hi all!

I have a 4 year experience with mods and repairable atties but I am totally new to TC.

I bought a vt75 nano, ensured that it's internal screws are ok, I cleaned the poles and configured it with escribe. I don't have a way to measure the internal resistance at the moment so i put an approx value (0.004). I have also run the case analyzer under stable temperature room conditions.


I decided to start with dicodes nife30, because I wanted to be sure about the TCR value of the wire I am using (320). I created two materials. One with the TCR value and one with a TFR csv from steam engine (Resistherm option). 

My coil is approx 8-9 open turns with a 2.5 internal diameter (I also tested with 3mm with no change in performance).

I checked the stability of the resistance with the atomizer analyzer and it seems that it's sable as the changes are on the third digit (0.476 - 0.478 for example).

I have been doing my tests for the last three days with two rebuildables (tilemachos V2 plus and modded kayfun 4 with a changed pole to have stable resistance). I set the max power at 17 Watt, without preheat and the temperature at 465F which was suggested by dani users. 

With all these settings vaping is horrible. In order to get the same vaping experience with kanthal/16 Watt, I have to raise the temperature to 520F which I believe it's not normal.

Do you have any suggestion on my issue? Is it normal to have to go to these temperatures to get what I am used to with kanthal?

Many thanks in advance!

[Wayneo]

Steam-engine.   Have you checked the 'heat flux' of both builds in their 'coil wrapping' section for general equivalence?

[tux]

Wayneo,

many thanks for your reply. I didn't know this interesting tool. Below you can find an approximate calculation of my current setup:





I assume that it shouldn't be that hot.

Any comments are highly appreciated!

[Wayneo]

All I was really trying to show, was that two different wire types/gauges have different power requirements. So just because 16 watts in Kanthal works for you, to get the same from another wire type or coil would be different.

There is no right or wrong 'hotness' of the vape, just what you prefer.

I don't know of a conversion from the heat flux value and wattage to temperature, but at least you know if you like a hotter or cooler vape. The same temperature value of different wire types/gauges should be the same though.

I've never used that wire. In Device monitor, do you actually come up to temp using such a low value, and high temp? A print screen of both the profile and firing with the 'temp' options checked works wonders.

[bdaines]

Some findings to report:

Ran all my analyzers, shorted the 510 as best as could with what materials I had (some stranded silver wire balled up and jammed in the 510, used lowest resistance measured). 

After all that, I've achieved basically the same behavior as the Dicodes reference.

This concludes another noob post.  Here are the results.

Mod: MarkBugs Amulet DNA75
Eliquid: 80% VG
Atty: Gem 2 (not-really-cloud-bro rta)
Coil: 28g GeekVape 316L, 7 wraps, 2mm ID, 1mm±0.1 spaced wrapps

amulet.ecig

[retird]

Looked at your .ecig file.  It looks like Profile 1 and 2 are set for the GEM atty you defined and both profiles are for SS material.  You say you have achieved the vape you desire.

Only wanted to comment that in both profiles you have set the pre-heat  to 1 watt.  You might see some benefit in ramp up time if you want to adjust this up a bit. Just a thought.... 

[black lace]

Back to the original post, (((unstable coil))) i think it was waynio did a small write up a few weeks ago, on how to pre heat and tune stainless, beffor finaly setting it to work,, 100 degrees extra heat to get a decent draw is a text book example of an unstable coil material, because it hasnt been properly heat treated.. the board is proving that it works, its the coils that are haywire..and confusing the board, it only works on one programed csv file at a time, so the coil must be sound,,, ( stainless proves to be critical)

[bdaines]

black lace said:

Back to the original post, (((unstable coil))) i think it was waynio did a small write up a few weeks ago, on how to pre heat and tune stainless, beffor finaly setting it to work,, 100 degrees extra heat to get a decent draw is a text book example of an unstable coil material, because it hasnt been properly heat treated.. the board is proving that it works, its the coils that are haywire..and confusing the board, it only works on one programed csv file at a time, so the coil must be sound,,, ( stainless proves to be critical)

I have noticed that the TC has gotten more stable as the coil "breaks in"  Can you link me to that post on preparing the SS? Thanks.

[black lace]

Am on mobile do having difficulty on a small screen, try this https://forum.evolvapor.com/topic/66167-topic/?do=findComment&comment=894494 and also ther is a further link in that thread.. at #2.. hope there are some idears there for ya..

[Wayneo]

@black lace. Oooh that thread. The user never did report back what worked and Viruk (low punch) had posted something completely opposite to me (high punch). Either way, I'd just say set up another profile with 'low' punch.

What's also missing from there, is that after seeing the results for that type of coil, one can then fine tune/change all 3 parameters to their coil build if they wish (to get all fancy).

Ramblings:
I leave my settings high and let the board do its job, which it does. (That little 5F over temp (Karloz spike) at ramp up on an initial cold coil is not even worth typing about)
Jaquith back in the old days, with the old algorithim, got better results with low punch for SS.

[black lace]

I remember he said that aswell, Best tip i can give anyone is allways buy from a reputable supply like **stealth vape** so one can be confident that whats on the spool is as the label says.. there was great debate , lol, about how we all achive the same results, high or low watts to hit set temp, i stay low ish and never hit temp protected, just a shave below with nice steady ramp up, each to their own, but my view is if a coil material is causing so much headach, i would be questioning have i been sold garbadge... and looking at my coil building..

[VapingBad]

I have never found high preheat to cause any problems and I tried hard with loads of ss profiles, from what I have seen it make virtually no difference to the smoothness of regulation, but really improves your vape experience.  I would advise people not to set watts much higher than you vape at (protects you if you fire with the wrong wire profile) and double that value for preheat watts, punch 11 and ph time 2 s YMMV.  I also get my ss from StealthVape and completely agree with what blacklace said: "if a coil material is causing so much headach, i would be questioning have i been sold garbadge... and looking at my coil building".  IMO the Karloz spike (tiny bump) is most likely the effect of the way heat is spreading and building up in the coil and build specific.

[Wayneo]

@SaintVapingBad "I would advise people not to set watts much higher than you vape at (protects you if you fire with the wrong wire profile)" that was the fancy part I was talking about. Luckily I've never made that mistake.

But continuing on, there's also been talk/suggestion of being able to have preheat changed to a % of wattage instead of a hard value, which imho would be better. Any thoughts on that, or would that require a multi page thread with conversation/arguing ala the temperature dominant display thread?

[VapingBad]

lol SinnerWaynoe

[black lace]

I think i had this discution beffor, you know when you gently break in a kanthal coil with a warn battery and gently puls burst it to get it to heat from the center outwards and you can actually whach it heat to a cherry red from centre outward,, well because when using stainless and say titanium one wouldnt be aiming for thoes temperatures and not many of us have thermal image cameras to see whats going on with power and heat moving through it, but i'm absolutly convinced that if the preheat and wattage is set too high and too long on initial start up (breakin) on a new coil, one can actualy blow a hot spot (week point) and permenantly damaged what would have been a deacent coil if had been done slowly to start with. that was the way i had read what jaqwith was on about with turning the preheat right down on stainless, as a rule of thumb, so it doesnt get boogerd up in its first few seconds.