HugeEgo

One of those guys on ECF with "supposed" experience in the wire industry is a former aerospace engineer who specifically worked with titanium and titanium alloys in aircraft designs. He has papers published in the scientific literature and is an expert on the metal and its properties. (Drucker is his handle on ECF, iirc). There was another guy, too, who was an engineer at Corning. He chimed in and said it's all BS as well. So, yes, these guys are fully qualified to say that SSV is full of crap (and they are). Any time you hear marketing terms like "special blend" or "proprietary secret" you know it's BS 99% of the time. SSV is a vape company -- not a wire extrusion factory. They are merely buying their wire from some factory somewhere that probably sells it to 1000 other clients in various industries. They have no secret recipe. They don't even have engineers or metallurgists. It's just a couple of guys who own a vape shop making up stuff so they can charge outrageous prices for wire. Are you going to believe SSV (who have no expertise, no credentials and have a profit motive) or are you going to believe former aerospace engineers who used to study titanium for use on aircraft?

Try the TFR curve for 430 SS and see if that gets you in the ballpark.

It's titanium, so it will be as safe as any other titanium. TEMCo is reputable and sells high-quality (usually made in the USA) wire. Their Kanthal, for instance, is made by Sandvik themselves. You can e-mail them and ask. They usually respond to e-mails very quickly.

The grade doesn't matter for advanced users (like most of us DNA-200 users), but it does matter for new TC users who buy SSV Ti wire and throw it on their Joyetech TC mod. It's not going to work at all. New users will be forced to go hunt down the SSV TCR value, which they probably aren't going to do. Because I can buy grade 1 Ti wire all day for about $10 for 50 feet. SSV charges, what? $1 per foot? Grade 1 is the purest commercially available and thus it will be the closest to the TCR values found in scientific literature for pure titanium.

First of all, SSV's wire is not grade 1. And second of all, no it is not worth the money.

Blasphemy. VapeBros before Hoes.

Yep, I think you are onto something. The change in voltage and/or amperage needed to maintain the temperature are too small to do on the fly accurately (or at least this is the best explanation in my non-EE view).

Yes, all of that is correct. Another way of looking at it for a given coil is to use the steam-engine formula for "TC Precision" (TCR * R * 1,000,000). However, consider the following: Let's say we vape at 232°C (450°F) and assume the room temperature is always 20°C. Now, let's calculate a few different scenarios for various wires. I chose these at random using a 3mm bit with roughly the same wraps for each. 316L stainless: Initial resistance at 20°C = .341? Final resistance at 232°C = .409? TCR = .00094 Total ?R = .068? Total percent increase in R = 20% Ti Grade 1 coil: Initial resistance at 20°C = .247? Final resistance at 232°C = .439? TCR = .00366 Total ?R = .192? Total percent increase in R = 78% Ni-200 Coil: Initial resistance at 20°C = .05? Final resistance at 232°C = .114? TCR = .006 Total ?R = .064? Total percent increase in R = 128% As you can see the total change in resistance is 128% in nickel, 78% for Ti, and 20% for 316L. Even though the absolute rise in R (316L and the Ni-200 coils had almost the same total change in R) is not that much different, I think the overall change in resistance relative to the starting resistance of the coil is somehow affecting the accuracy. Whether this can be overcome, I do not know. TL;DR -- Ask John. I would be interested to know as well.

I am using a dual coil 26ga 317L build right now (.270 ohms). My board reads it fine, but it seems to go back into power mode if I make a single coil build. But in dual coil mode, it works great and seems pretty accurate using the default 317L .csv file from steam-engine. I would test it with my thermocouple, but it's very hard to get an accurate reading due to the fact the thermocouple end is made of metal and shorts the coil. And I haven't found something suitable to insulate the thermocouple without drastically affecting the accuracy.

It's really not Evolv's problem. It is one of those "it is what it is" type of things. The TCR of 316/317 SS is what it is. Evolv can't change the laws of chemistry. Is it possible they could make improvements to the board in the future to compensate? I suppose it's possible, but I doubt this is something that could be improved upon with firmware updates. It would take an even more accurate ohm reader (that can read beyond the milliohm range -- say in microohm range). I don't know if this is physically possible to do with current technology, at least not accurately for our application where we are screwing in atomizers with 510 connections, etc. It's already hard enough to get an accurate milliohm reading. But I could be wrong, I am not an EE.

Yeah. I don't know why anyone still uses Ni-200, tbh. Can't be dry burned (can't be cleaned), have to recoil every couple days, and it has a super low resistance which is annoying. To each their own, though.

I use Ti and SS (317L and 430). As for nickel, I look at it as "why bother?" I haven't tried any of the NiFe alloys and probably won't because they contain, well, nickel (yes so does 316/317 SS, but in much smaller amounts).

My board won't read 26 gauge 317L wire without jumping back to wattage mode. If I use dual coils, it reads it fine. It's strange. (317 is pretty much the same as 316 with a slightly lower TCR).

Are you using stock Herakles heads or an RBA with your own wire? If it's the former, then it's probable that the wire they are using in the herakles is not really 316L. I know I've experienced this with Joyetech "316" stock heads. They are closer to 304 grade than they are 316. I suspect these Chinese companies are using the cheaper 304 wire and simply calling it "316" when it's not. Try a TCR of about .001016 and see if that improves it (that's the TCR of 304). There's nothing wrong with using titanium coils, which are much more accurate due to the higher TCR. Set your mod at 0.00366 and vape on.

I've got a spool of 28 gauge and it works well. It is certainly more accurate in TC mode than 316/317. I don't use it much, though, because I am leery of its durability. It isn't as corrosion resistant as the 300 grades. @Lance, why are you using the 304 .csv file for 430? Steam-engine has a 430 .csv file posted.