Uwell Crown Tank - Stainless Coil - TCMode

[jj6404]

Powerman said:

Exactly. 105 works cause it bigger than 0.001,but who knows if it rounds off. Go over to general and I have a thread about the VS and VT200. The short answer is I have both and my VT200 does not hit as hard as my VS and it's 50 degrees higher with same profile. Close but not the same.

Why would they hit so differently if your mod resistance is set accurately on both?

[Powerman]

Haven't figured it out yet. On its own, it's fine. It works. But side by side, it's different.

[Margucci]

i am getting a most constant vape on the 0.5ohm SS coils in TC mode. it was suggested that the Ni leads in the coils are what is causing the TC issues in the crown coils. this is necessary so that the final resistance of the coil is what is intended (since Ni resistance is incredibly low. i was thinking that perhaps the reason why i am getting a better TC vape with the 0.5ohm coils is because the Ni leads are shorter. because the total coil resistance of the coil is higher there is more SS wire and less Ni. just an idea i had. 

[Powerman]

Doesn't higher resistance mean less material? Larger wire is less resistance. Longer wire adds. But the nickel legs are necessary for vertical coils. Long legs to get from top to bottom. If it was the same material, it would add resistance where it isn't wanted. It's wanted at the coil that is wicked and in the air flow.

[Margucci]

yup thats the point. the higher intended resistance for the coil the more SS there is and thus you would have less nickel. however, while the SS wire you want to heat up is, so is the nickel wire. in power mode this doesnt matter at all. however, in TC mode the TCR of the nickel needs to be taken into acount as well. so i have reasoned (although im not sure) that on the higher resistance coils the ratio of stainless:nickel is higher. what would result is an effective TCR closer to that of SS than you would have on the 0.25ohm coils. this is just something i may be thinking is the case to explain why the vape in TC seems to be better. uwell could also accomplish this by having the same length nickel leads on either coil but with the 0.5ohm coil just having thinner wire. its very difficult to tell from peeking in the top. 

[jj6404]

1) isn't vaping nickel in power mode very dangerous?? 2) so can anyone recommend a different tcr than the ones we currently use for SS that will account for the nickel legs and give us a better vape with tc?

[Margucci]

1) yes and no. nickel wire has been used in coils for a while now. i believe the primary concern initially when people started using Ni wire was that the resistance was so low. even looking back a year, how many regulated mods (and even more so with mechs) allowed you to fire down to sub 0.2ohm? battery safety was certainly an issue until recently. as for the gasses people talk about being released by Ni.... im a little more skeptical. it may very well do that. however, if that is the case you would be breathing it in anyways because of the way that so many coils today are designed. also, there is no issue at all vaping Ni in power mode. it would just have an extremely low ramp up time. when you start off your vape in TC mode the higher wattage quickly heats the wire before the wattage is cut when the coil is at temperature. so without the real time wattage control your coil would take much longer to heat up because you dont have that initial burst. for example when you start your vape lets say 75W is going to the coil. after perhaps a second that is down to lets say 30W. if you set the mod at 30W yourself there would be no difference because that is the equilibrium point for that temperature. however, this is compounded because of the nature of the wire. Ni has a steel TCR curve. so when the coil is cold it takes even higher wattage to heat the coil up (as easily seen if you are running a 0.15ohm coil at 40W vs. a 0.5ohm coil at 40W). so the final result is that you need even a larger initial burst of power because of the resistance change to get the coil up to that equilibrium point. the same thing can be said about Ti wire although not to the same extent as nickel. something like stainless can be run in either mode because the TCR is much more constant. 

2) thats unlikely with these coils. if you look inside the top of the coil both the nickel leads and the SS wire are touching cotton. this would create uneven heating across the linear length of the wire and if you arent careful could cause burning of the wick in certain areas. if the coils were made from the start with the intention of them being SS TC coils i dont believe we would be having near the issue we are currently. 

[Powerman]

The nickel legs are the same. Higher resistance means less SS, not more. So the ratio of nickle to SS is worse for higher resistance.

[Scottericsonon]

jj6404 said:

I've tried the 304 from steam engine, tried the "crown" one from Facebook. They both sucked for me. So I did a custom and just put in 0.00105 for the tcr like you said and and 65 watts 80watt preheat and 550 degrees it's very close to the straight power at 60 watts that I love but sometimes it still feels airy and cuts prematurely. How can you have your wattage set that high with the crown ?? I had one profile set with the 304 from steam engine I believe but with 200 preheat, 540 degrees, 65 watts and one hit fried my coil head. It gave me the nastiest dry hit obviously.

That wattage works for me... I just crank it up and let the temperature control do its thing and regulate the applied wattage.... Watch the screen as I vape, temp runs to where I have it set almost immediately (which is what I was going for) and if I take a hard pull on it (hard enough to kick it down off of temperature) it applies about 50watts or so for the split second it takes to get back to temp..