Stainless steel

[Bobby]

Vaportron said:

so i increased my watts and it looks like this
tc is working even though it looks erratic.
whats your actual problem?

Fair enough. If you consider that behavior as working temperature control and are happy vaping it like that, I guess we have nothing more to discuss.
I consider that erratic behavior not a 'working' TC since the temperature error is much too big ( >60 - 100F) and my actual problem with that, is the resulting inconsistency of the vape and the variation in taste and warmth.
Such a large error is not 'control' but a poor attempt to regulate. According to what I read on forums, other mods seem to do a good job with TC on SS, so why not the DNA200?

[blueridgedog]

316 and 317 have a pretty low tcr.  Many of the success stories you hear are based on 410 and the other higher tcr value SS blends.

[Bobby]

Hmmm, it's my impression that most of the factory coils and popular wires tend to be 316L and the 'succes stories' I see use this wire or these coils.
Do I understand you correctly that you are saying that true TC on wire that has a TCR in the 0.001 region is not possible, so the succes stories I read of SS316L are actually based on vaping this in VW mode with a temperature limit (like the first screenshot of Vapertron)?

I will see if I can get some SS410 to test if this will do true TC. In the meantime it would be great to see a screenshot of the device monitor with this wire.

[blueridgedog]

Bobby said:

Hmmm, it's my impression that most of the factory coils and popular wires tend to be 316L and the 'succes stories' I see use this wire or these coils.
Do I understand you correctly that you are saying that true TC on wire that has a TCR in the 0.001 region is not possible, so the succes stories I read of SS316L are actually based on vaping this in VW mode with a temperature limit (like the first screenshot of Vapertron)?

I will see if I can get some SS410 to test if this will do true TC. In the meantime it would be great to see a screenshot of the device monitor with this wire.

I think there are success stories with 316/317 but there are also a lot of people vaping it in VW mode, and some probably do think they are in temp mode.  The TCR of these is so low that you have to have a significant coil and a near perfect atomizer along with a base resistance figure in the escribe setup to get it right.  The DNA200 is the only chip that will let actually see how it is scrambling to use it in TC mode.

[Spector NS5 RD]

blueridgedog said:

[QUOTE=Bobby]Hmmm, it's my impression that most of the factory coils and popular wires tend to be 316L and the 'succes stories' I see use this wire or these coils.
Do I understand you correctly that you are saying that true TC on wire that has a TCR in the 0.001 region is not possible, so the succes stories I read of SS316L are actually based on vaping this in VW mode with a temperature limit (like the first screenshot of Vapertron)?

I will see if I can get some SS410 to test if this will do true TC. In the meantime it would be great to see a screenshot of the device monitor with this wire.

I think there are success stories with 316/317 but there are also a lot of people vaping it in VW mode, and some probably do think they are in temp mode.  The TCR of these is so low that you have to have a significant coil and a near perfect atomizer along with a base resistance figure in the escribe setup to get it right.  The DNA200 is the only chip that will let actually see how it is scrambling to use it in TC mode.[/QUOTE]i agree with that entire paragraph, lol. if any other board manufacture had a device monitor style live view of what the board has to do to accommodate SS's tiny TCR, you would most definitely see the chip trying it's hardest to maintain a set temp, aka "the Rocky Mountain peaks and dips" of the temp, wattage etc lines. funny thing is, if you know what you're doing, you can get a very decent vape out of 316L. 

i find, i completely turn off the preheat feature in escribe. i input a TCR value of .00092 instead of a csv curve. then i build my coil (spaced then dry burned to work out hot spots) and make sure the coil leads are secure under the screw heads (i loop the entire wire around the bottom of the screw head, essentially making an eyelet out of the wire ends). wick then fill tank, or rda. set my temp to say......520-550°F. 25-30 watts. vape it once. let sit for a while so refinement does it's job. then lock my ohms after the board has refined my res as low as it can be.  then fine tune with wattage/temp until i get the vape i want. works every time. i use UD 316L.

all of this is under the assumption you have an atty that has as few connection points as possible and a solid 510 pin. the Lemo, Lemo Drop, and Lemo 2 are not so good, as they have a removable base, for any TC wires. IMO.

[Bobby]

So why has nobody in the vapor community debunked the fairytale of TC on stainless steel? I did not read this anywhere. Did I miss this?
Sure you can get a decent vape on stainless steel as long as you take care that the setpoint temperature is not reached and the mod is not regulating the power to maintain the temperature. You could also say that, in reality TC is mend to be temperature limiting but with a temperature error of >100F, it will not even do that properly when using stainless steel.

If you want to look at TC with other mods that do not have a device monitor, you can hook up an oscilloscope and look at the voltage. If you see a smooth drop in the voltage, the mod is regulating the power properly to maintain the temperature. If you see an erratic curve, the mod is not regulating the power properly. I do not have the setup to do this but some of the reviewers do, for example: here is the German reviewer Obi doing this (on a DNA200 with a Ni200 coil). Why haven't any of them done this with stainless steel?

To avoid misunderstandings: I do not have a problem since I do not have issues using Ni200 or Ti and also can get a decent vape out of SS. This is only to expand my knowledge and understanding about my vaping hobby.

[VapingBad]

I have not got much experience with ss and prefer Ni200, maybe I just got used to it from DNA40s, anyway at first I though ss was surprisingly good after realising that pulsing new coils was necessary.  But after playing with the settings more I realise that my original opinion that the TCR is too low to work really well was correct for the set up I have anyway.  Preheat works very well and I did not find it caused any problems at all like some people have suggested, I guess because it just limits once and does not try to regulate the temp. They maybe able to tune the control loop timing or reducing the degree of power attenuation for low TCR materials to alleviate this to some degree in future firmware or designs. IDK if these will work just a guess.  

ATM I find this is a good compromise:
You can use 200 W, punch 11 preheat to get the coil hot quickly and view in device monitor to find a power level that keeps it below the temperature limit during normal vaping for a great vape. If you increase the temperature limit then you can really feel the chopping and it is just better and smoother to keep below this IMO, but if you are interested this is quite revealing. 
(dual horiz 10 wrap 0.4 mm ss317L 2 mm coils in amromanizer RDTA)

YMMV and as I said I have not got much experience with ss just musings from one set up with one kind of wire.

[Spector NS5 RD]

Bobby said:

So why has nobody in the vapor community debunked the fairytale of TC on stainless steel? I did not read this anywhere. Did I miss this?
Sure you can get a decent vape on stainless steel as long as you take care that the setpoint temperature is not reached and the mod is not regulating the power to maintain the temperature. You could also say that, in reality TC is mend to be temperature limiting but with a temperature error of >100F, it will not even do that properly when using stainless steel.

If you want to look at TC with other mods that do not have a device monitor, you can hook up an oscilloscope and look at the voltage. If you see a smooth drop in the voltage, the mod is regulating the power properly to maintain the temperature. If you see an erratic curve, the mod is not regulating the power properly. I do not have the setup to do this but some of the reviewers do, for example: here is the German reviewer Obi doing this (on a DNA200 with a Ni200 coil). Why haven't any of them done this with stainless steel?

To avoid misunderstandings: I do not have a problem since I do not have issues using Ni200 or Ti and also can get a decent vape out of SS. This is only to expand my knowledge and understanding about my vaping hobby.

have you tried a good SS? i can reach my set temp and the the vape is fine. with the right tcr/csv, there should not be a 100° error. as for reviewers doing SS with an osc., when you find one let me know.

i don't know if there is anything to "debunk" about SS. however, i agree it is the crappiest wire out of the many TC wires that are out there. i much prefer Ti over any other that's my go to wire. but it is what it is with SS small TCR makes that board work extra hard to maintain a set temp.

[Bobby]

ChunkyButt200 said:

have you tried a good SS?

Yes, I see this on different wires, factory SS coils (and different atty's). It is imho really the TC regulating the power (to hold the setpoint temperature) that is erratic.

ChunkyButt200 said:

i can reach my set temp and the the vape is fine.

Please, please post a screenshot of the device monitor of this (if it is really regulating to maintain the temperature and not putting out the set power for the duration of the puff). 

ChunkyButt200 said:

with the right tcr/csv, there should not be a 100° error.

A TCR/csv that is slightly off only results in an offset between actual and measured temperature and will not cause the erratic behavior. (The mod doesn't know the actual temperature, only knows what it measures and what TCR/TFR values are put in its memory. That's why you can for example do TC on a Ti coil with a mod that only has a nickel setting).

ChunkyButt200 said:

i don't know if there is anything to "debunk" about SS.

Well, if it is too inaccurate for true TC and vendors are pushing SS coils and the SS option in their mods as the latest and greatest, it would be good to know the true story. It will save a lot of headaches for vapers starting with SS.

[blueridgedog]

As a final suggestion, SS is an alloy and each can have slight variations from the standard formulation.  Take ten samples of 316 from ten manufactures and you will get a variety of real world TCR values, depending on the exact composition of the wire.  Ti and Ni are easier, in that they are generally in pure form and therefore easy to dial in.

[Bobby]

@blueridgedog see my remark in my previous post:

"A TCR/csv that is slightly off only results in an offset between actual and measured temperature and will not cause the erratic behavior. (The mod doesn't know the actual temperature, only knows what it measures and what TCR/TFR values are put in its memory. That's why you can for example do TC on a Ti coil with a mod that only has a nickel setting)."

[Spector NS5 RD]

Bobby said:

[QUOTE=ChunkyButt200]have you tried a good SS?

Yes, I see this on different wires, factory SS coils (and different atty's). It is imho really the TC regulating the power (to hold the setpoint temperature) that is erratic.

ChunkyButt200 said:

i can reach my set temp and the the vape is fine.

Please, please post a screenshot of the device monitor of this (if it is really regulating to maintain the temperature and not putting out the set power for the duration of the puff). 

ChunkyButt200 said:

with the right tcr/csv, there should not be a 100° error.

A TCR/csv that is slightly off only results in an offset between actual and measured temperature and will not cause the erratic behavior. (The mod doesn't know the actual temperature, only knows what it measures and what TCR/TFR values are put in its memory. That's why you can for example do TC on a Ti coil with a mod that only has a nickel setting).

ChunkyButt200 said:

i don't know if there is anything to "debunk" about SS.

Well, if it is too inaccurate for true TC and vendors are pushing SS coils and the SS option in their mods as the latest and greatest, it would be good to know the true story. It will save a lot of headaches for vapers starting with SS.[/QUOTE]to save time. yes SS sucks. out of the many other TC wires i.e. Ni, Ti, NiFe, tungsten, etc., SS is the next above kanthal. 

if i took a screen shot it'll look jumpy. SS has the tiniest tcr out of the better choices for tc wire. you'll never get a steady line in dm with ss.  but i don't notice it during the vape. 

[Viruk]

I'll try to take a screenshot later if I can, my attempts at TC with SS are with the Triton 0.4 ohm coils - those are 316L. I used the csv from steam-engine.

It kind of worked, but the temp wasn't stable at all. The temp graph jumped about all over the place and the vape was much weaker than when vaping in power mode at the recommended wattage so I just ended up switching back to power mode on those coils.

Just an update on my own experience of TC on SS which may be of interest here...

update - can't post screenshots yet as my 0.4 ohm SS coils are on the other side of the Atlantic, if I can pick up some coils locally I'll do this and post

[Conanthewarrior]

Right-you may remember I was having a lot of trouble with SS, and found SS317L to work the best. 

I received a Joyetech Cuboid a few days ago-and SS316L worked perfectly on this-so I thought, I am getting it to work on my Evolv devices, if this can do it well at a fraction of the cost-I sure can make the DNA200 do it too. 

I am using a new tank, a Geekvape griffin, with dual 26G 3MM ID unspaced coils at 0.37 Ohms this time round, and guess what? It is working perfectly. 

The TC is working great, I even vaped down to an empty tank to try and get a dry hit, this would not happen. 

The temp range seems to be correct, similar to my other wires at the same temp settings, and I am so happy. 

And you know what profile I am using? 

The one that comes with the Efusion, which I believe Evolv made, or I may be mistaken and they are straight from steam engine. 

I am putting this on to all my other DNA200's now, as it is working perfectly. 

I am using 316L, I thought it would never work as good as this, but it is. 

All I did was reduce the preheat and lock ohms,and using a new new tank, and the coils are 3MM ID instead of 2MM. 

All I know, is it is working as it is supposed too-not kicking me out of TC mode into wattage mode as it used too, and I have done one thing different-the resistance is locked. 

Super happy, over the moon in fact. 

SS316L will now be my wire of choice due to its ability to be used in power and temp mode-which is handy for me with memory issues and over 30 tanks and drippers. 

You can download the Efusion settings from here I believe, I googled Efusion DNA200 settings, and got them from here to make sure they was the original settings that come with the device. 

I have also changed the preheat from 150W to a more sedate 60W. (EDIT: Sorry, double checking, it is 80W preheat). 

I hope that this may help others. I am using Crazy Wire SS at the moment. 

Good luck everyone-I know it can work well, as it now is . 

Conan. 

EDIT: I have added this CSV to all 3 of my devices, a 4th is on the way back from RMA repair-and I have made 2 more builds, this time on RDA'S. 

I tried a single coil, 3MM ID 6 wrap at 0.42, and a dual coil setup in another dripper, around 0.38, and both are working flawlessly. 

I can now actually use SS as my wire of choice, which has made me very happy. 

Temp control is working fully, and you can completely dry the wick of juice without a dry hit. 

So, SS316L finally cracked for me-time to convert all the others now . 

[Bobby]

Conan, please post a screenshot of the device monitor or to use a famous interweb quote: "Pics or it didn't happen".

[black lace]

Connan.. do the 3mm coils fit easy, left over space around sides of chimney ect?? Havnt got fisyical acsess to one, beffor purchase.

[VapingBad]

After my complete fail with vape mesh co 317L 0.4 mm ss I did some scorch testing on it and none of the ss profiles on Steam Engine worked with this wire it was way too hot, too low TCR and just unsuitable wire.  Then I tried the 0.29 mm 316L and the scorch test was pretty good so I vaped it on device monitor to get some screen shots for Bobby.
 

[Bobby]

@Vapingbad; Thanks for the screen dumps, I learned something again.
I guess this confirms that with true TC and SS you have to go super-ohm instead of sub-ohm and you can't build thick builds with thick wires since than the resistance will drop too low.
I found that dual coils of thick Ti Gr I (0.5 mm or 24 gauge) also have a too large temperature error. At least I now know what to avoid and why.

[VapingBad]

I don't know, but I think the match between the wire and materials profile is probably an important issue at least if that is not very close you are not going to get good results.  Have other people been doing single coil scorch tests and comparing them to Ni200?   I know the 317L I had was running way too hot, but the 316L was very close to Ni.  I'm sure the mass of the coil plays a part to, but IMO you should get a profile that matches the wire for at least 100 F each side of your vape temperature before drawing too many conclusions.

On the first plot you can see it getting spikier as the wick started drying, I think I put more liquid on the second one and could be why it is smoother.  And that the most aggressive preheat setting didn't adversely affect it.

[Bobby]

I know some of the YT reviewers do cotton burn tests. The only ones I know who always do a lot of measurements when reviewing a mod, are DJLsb Vapes and Obi.

Isn't it so that the only relevance of the TCR or TFR curve is the link between what the mod regulated to and the real world temperature. For the mod it doesn't make a difference to what real world temperature it regulates. It only looks at resistance change and to what resistance value to regulate. It does this by calculating the resistance value from the setpoint temperature, the TCR value or the TFR curve and the cold resistance reference (it will also put the readings of the PCB and housing temp sensors into the equation, but I leave that out for simplicity)
Yes, if the value or the curve is not correct, it will get too hot or not hot enough, but the mod will still regulate at that high (or low) temperature since it doesn't know it is not correct. That is why you can vape Ti on a mod with only a NI200 setting by setting the temperature lower (there is even a chart for).

[VapingBad]

My point was the 317L ss that came from the vape mesh co had a much lower TCR, it would have been extremely low if it matched SteamEngine's value of 0.00094, but the wire got roughly 150 - 200 F too hot.  At a TCR 0.00094 the board would expect a rise of 28.4% form 70 F - 600 F, but my guess on temp suggests and it is just that as I didn't accurately measure the temp that the actual TCR is about 0.0007 - 0.00075, that would give a 28.4% raise in res from 70 F - 800 F and 70 F - 750 F respectively.   Not very accurate or scientific and maybe overstating the degree of error in the TCR, but the extremely low TCR is pushing the envelope a bit too much ATM.  Higher TCR should not be such a problem, but if it is out I doubt it will be higher.  And I have been running Ti on a DNA40, but it has a much higher TCR than any ss alloy, 3-4 times higher.

Contrast that to NiFe30 which only about twice res than Ni200 or Ti both regulate extremely well with 0.4 mm wire, the 316L that worked was 0.29 mm about half the cross sectional thickness of 0.4 mm.   If I get a change I may make up a twisted 316L coil to increase the bulk (thermal inertia), 2 strands will be within 10% of the 0.4 mm x-sectional area and see how that performs, but the 0.4 mm NiFe30 I have from Stealth Vape works so well it is hard to get the motivation especially as I just put a dual Ni Clapton on the atty I use for this.

[VapingBad]

Stealth Vape just listed 316 so I have ordered 3 sizes to have a play with as I trust them to have the correct spec.

[Bobby]

Well, have fun. I am curious about the results of your experiments.

My reply was about the fact that the issues with SS can't be solved by tweaking the TCR values or curve, but that you need to build coils with higher resistance to reduce the error. The thicker the wire, the more challenging it gets and with 'multiwire' builds (claptons, etc) it gets near to impossible. Fortunately we can still enjoy these in powermode (or temp limiting mode).

[VapingBad]

It does seem so, though I wonder to what extent so I ordered 0.2, 0.3 & 0.4 mm of the same grade and batch from the same supplier, one I trust to check out the quality of the wire before they list it.

[VapingBad]

Got my wire from Stealth Vape and only have time for a quick test right now so I used the thickest 0.4 mm and it is regulating temperature, not as smoothly as higher TCR wires, but it is doing it especially protecting against high temp.
  (time base 10 seconds)