Temp Control and Stainless Steel

[firemanjim]

I seem to be having issues with stainless steel (317L) and temp control. I have not tried any other wires other than kanthal.

When I first made my coils I put some cotton in the wick and set to 200C and fired it and immediately the cotton burst into flames.

With no cotton in the coils were pulsing bright orange - clearly not something expected from temp mode.

I tried again with another RDA. This time I set the temperature much lower at 150, tried spaced coils and didn't even try and fire until juice was on.

Extremely erratic vape experience. Sometimes it would work, other times it would throttle the watts to nothing.Even when working I could taste the warming and cooling significantly as the coils were pulsing. In the end I switched back to kanthal in normal mode.

The temp curve was downloaded from steam-engine and I recorded the results in the device monitor.

 

I have no idea what is going on here but it is certain it is not working correctly. 

Any ideas?

[UKDTweak]

I saw something similar on my mod with 317l, then i cleaned the 510 threads on both the mod and atty and its been solid since.

[seankwong]

Did you decrease the default preheat and load SS TCR into one the profile? If no, download a SS TCR csv file from steamengine website, load the csv file into one of the profile, temp set at 400F, decrease preheat to 15 and set fire wattage to 30w. Build a spaced coil at 0.3ohm, juice the wick, put on the tank, select the SS profile on the mod and let it idle for 20 seconds. Pulse fire it before vaping, make sure ohms are consistent and hopefully it works for you.

[r4nd0m]

I see this on my vaporshark dna200 - when using Celsius - when setting it to F it seems to work just fine ... might be worth a try as I can see you are using Celsius as well ..

[eziotroito]

Same story here... With 316L SS 0.60 first attempt and 0.50 second attempt, 6 wraps per coil - inconsistent temp curve staying at what device monitor says. No issue with nichel on the same atomizer. Later I'll try to use another atom and see what happens. To simplify tests o don't wrap and don't wick my coil just letting the wire looped and check device monitor while pulsing and firing. It just does not work. Downloaded csv files but did not change preheat and let it at 80 °C, how it wat set before on ni200 Check this pic

[firemanjim]

 

Thanks for the replies and the assistance!

I changed to F, used the settings as mentioned by seankwong and then tweaked them a little and it does seem less erratic - maybe there is an issue with Celsius?

Does this graph seem more normal?

[firemanjim]

Sorry for double post but after posting this went back and had a puff - back to erratic behaviour - nothing has changed other than a minute or so of time and here is what I now get - virtually no vape...

 

[eziotroito]

Same issue here, man! Don't know what to do! Cleaned threading, brushed atom Pin and rebuild it again. No way to work for it! Just hoping for un update or something or waiting for Santa's/Jesus/Allah/Gamesh etc...  

[James]

eziotroito, does your mod have a mod resistance set?

If it *is* set but incorrectly and too high, it can cause control instability like this. Of course, if it is too low that can affect the accuracy of TC. It is much more important that your mod manufacturer set this accurately for SS. (If not, you can do it yourself, if you know/can measure it.) Nickel is less sensitive. You may get a better result with a higher-resistance coil, as that reduces the effect of mod resistance being set wrong.

It isn't a given that this is the problem, but certainly something to make sure of.

Also, do you have alternative wire you can try? The problem with SS is that (1) its resistance does not change as much as Nickel, and (2) it is an alloy and is not graded by electrical properties. That means not all SS is identical, so the curves may be off.

[eziotroito]

Hi @James, thank you for support. 1) My mod is a tugboat and I found someone who told me to set mod resistance to 0.007 and that's what I did. But my mod came to me set with a "zero" value. So I trusted that guy and set it to 0.007 at first day I received it. I'll search how to run this test, anyway. 2) yesterday I thought that maybe my .12 ohm resistance was too low, so I built a looped wire of 20cm (no wraps) of SS 316L with a total resistance of .90 ohm to be sure that my too low resistance was not causing the issue, but with no good results. 3) My SS wire came from zivipf.de a German well known wire as one of the best on the market. Also asked around discovering a lot of people are in trouble with SS. Also, my zivipf wire is going really flawlessly for someone (304L,316L,317L) but not for me, so at the moment I was not able to say what exactly is causing this behavior This weekend at vapitaly expo I'll get some 304 SS to try... Let you know and thanks for helping me

[James]

Hmm. 0.007 sounds very reasonable - many 510s are around this. Do try setting it to 0 to see if it helps stability though. It probably will not, but if it does that indicates the mod resistance was too high. I am surprised 0.90 Ohm did not help.

[vrsnake]

I am also seeing wildly fluctuating temperatures with SS316L (24g, made by UD) on multiple RDAs where the same atty with NI200 or T1-1 has rock steady temps.  I'm using an eFusion with the mod resistance set at 0.005 ohm.

[PZenger]

I'm having this same issue. Built up a 7 wrap 26g SS316L pair of coils. Put them on a sapor, wicked them up and the juiced them. The first pull was pretty good. Ohms were locked in at 0.21. Then it hit temp protect instantly and the voltage was wildly erratic. Exactly like this. I've been asking around to see if anyone has figured out why this happens but I can't seem to find anything. I'll keep looking though. 

[watcher64]

I am still a firm believer that it is because SS has such a flat TCR.  There is not enough variance in resistance for the chip to maintain temp without pulsing wildly.  But that is just my 2 cents worth ...

[ufaiq]

I'm facing the same problem gents, have reverted to nickel now.

[CADmanSolid]

Hi, im new on this forum but have played with 316l a fair bit on my vt200 hcigar, and my lavaboxes and have a very good system system going for this material.
This dna200 chip is a great piece of kit because you can trick it well depending on what alloys are in your wire. I use UD builders choice 316l with the wire wizard steam-engine.org curve for ss 316l elite.
I used a temp probe inside cotton through my coils to tune my method and found this to be spot on accurate temp give or take 5 or so degreesF.

i have found that any lower than 0.2 on ss316l is just to unstable to work with so i like to stick around the 0.2 0hms mark on 26awg for tanks and can go 24awg on drippers of ya like but it will be less stable.

This is my build and settings:

Dual contact coils 26awg @ 8 wraps on a 2.5mm post coming out @ 0.257 in a (Cloud chasers ink triforce rta deck that has a modded center pin right through from post to +510 bed for perfect conductivity) not important, you just need a good connection from coil to DNA chip (good atty).

My mod resistance is set to 0.007 (This is important).

Then I lock my ohms to 0.26 even though it is actually 0.257 (These small changes make a world of difference to your vape).

I set my pre heat to 1w, 0 punch, 0 seconds (This is important).

My over all wattage is set to 130w (this is important not to starve the power from the coils) but the DNA only sucks about 100-127w on a huge tooooot @ 535DegreesF and about  80w on a normal toot @ 480.

I have this build in a sapor, verlocity, CLT V2 and a stro v2 and i can vape the wicks to totally dry with no burn at 420-480 degreesF and nearly totally dry at 500 degrees. A true constant 500 DegreesF at that wattage is a real hot vape and will make your atty to hot to touch after about 3-4 good toots and will boil your mouth like Gplat Claptons on a stacked 26650 mech, but with only a good chip and a pee size set of coils..... well maybe my mind is a little spun but it is still a real mean vape, defo better than any kanthal build in normal vw mode or on a mech.

Just my 2000000000000000cents worth > <
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[mlambert09]

Word to the wise ...... READ CADmanSolid's post/answer. You'll throw that ni200 back in you box or trash which ever you prefer.

[Powerman]

Most folks are finding you can't use contact coils in TC. Yes that's known for nickle, but it seems to be the case with SS as well. Sure contacts can "work", but erratic and inconsistent performance. Makes sense to me. I have not had time to do some spaced to check performance. Seems with SS there has been a rash of problems. People seem to look at tank and mod and wicking and so forth. But it's common problems. Burnt hits with no obvious wick problem, or way too cool vape. Where as most resort to higher TCR or fake out ohm. Locking ohms is another one. Many people report rock steady reading on spaced coils. That's what I'll be doing next. I've also heard no preheat or higher ohm builds. But I'm suspecting those are bandaids to the real culprit.

[teilo]

I can confirm that SS requires spaced coils. Anything else is a disaster. 304 might be more tolerant given its higher TC gradiant, but with 316L it is a non-starter. I even set a wick on fire while trying to use compressed coils. I was about to give up on SS entirely when I tried a spaced coil. This made all the difference in the world.

YMMV, but preheat also seems to cause issues, so CADmanSolid's advice is good.

Locking the Ohms also helps a lot. But a word to the wise here: If you are doing a dual-coil build, and one coil comes loose, your base resistance will double, and you will burn your wick. So check your connections. Thankfully, compared to nickel, SS can take a lot more torque without breaking.

[MikeTheVapeDude]

I've used the Aspire Triton .3 316L SS coils in a Supertank Mini for a few days with the CVC off Steam Engine and it's worked great, though when I tried to use actual 317L wire I could NOT get it to work until I spaced the coils out (a lot, like OCD spaced perfectly, it was more trouble than it was worth imo) but when it finally did work it worked good. SS seems to be my personal favorite TC wire at this point, but I can feel the stress of trying to get 317L wire to function properly. But it CAN be done.

[watcher64]

To be honest I don't see how SS wire works at all for TC, just my opinion, but I think you guys are fooling yourselves.  The science just does not support SS being any good for TC.

NI 200 has a base resistance at minimum temp of .62 and at max of 3.52 that gives you 2.9 to play with to calculate the temp.
TI has a base resistance at minimum temp of .61 and at max of 2.45 giving you 1.84 in between to calculate.

SS on average has only 0.45 ohms of difference between min and max, that is a very slight amount to be able to calculate and maintain any accurate temps.

You can see this in device monitor as constant spikes above and below.

Just my .02

[MikeTheVapeDude]

I can tell the difference between regular wattage on stainless steel wire and TC curves on it. Besides, trying to vape with SS wire on a DNA200 tends to be a bit annoying as all of my DNA200 devices confuse themselves and start in TC mode then eventually swap to regular wattage. The coefficient of SS wire is high, yes, but TC is still definitely an option. It's not like you're using regular curves, it's a whole different material setting on the CSV, so that higher coefficient is accounted for in the different curve setup, and the much smaller changes in resistance can be accounted for by the device.

I mean, the experience will obviously differ, because the coefficients of the SS wire changes between type (304, 316L, 316, 317L, etc.) also, some different kinds of SS will work better. There's actually some types of SS wire with ideal coefficient ratings to use with TC, they're just not actively being used that I know of, it's kind of a all in theory thing. But I do know that with custom material settings on a new curve, the DNA200 can use SS wire with temperature control fairly well, maybe not as good as Nickel or Titanium, yet, but it's definitely a viable option. The future holds promise, though.

[watcher64]

Don't get me wrong , I am sure there is a difference ..

BUT, the DNA200 is not a magical device that can break the laws of physics ..

 

You have a chip that has to look at the temp setting, look at the current ohms, calculate the temp, then reset the voltage/wattage to achieve the required setting.

Now taking into account, the switching on and off of the power, the adjustment of the power and the fact that there is going to be heat loss/gain in that moment, unless they have magically managed to throw a super fast cpu, super fast transistors, switches, and voltage regulators on the board (which I know is not the case), the chances of getting super accurate temps is just not going to happen.

 

And yes there are different types of SS, but they all fall around the same variances, some a little higher and some a little lower, but, with this type of TC the variance in ohms is what determines how accurate it is.  The smaller the variance the less accurate it can physically be.

 

Again just my 0.02 and my personal opinion.

[VapingBad]

Personally I would not bother with SS, but never had a problem that I can solve with Ni200.  SS can work, obviously not as well as Ni or even Ti, but you need to have the mod res set correctly, an atty with good connections ant the right materials profile.
 

[watcher64]

VapingBad said:

Personally I would not bother with SS, but never had a problem that I can solve with Ni200.  SS can work, obviously not as well as Ni or even Ti, but you need to have the mod res set correctly, an atty with good connections ant the right materials profile.
 

 

That is exactly my point ... Thanks for posting that chart ..