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StemPod by MPL

Discussion in 'Portable Vaporizers' started by supershredderdan, Aug 3, 2017.

  1. Hippie

    Hippie Well-Known Member

    Messages:
    225
    You may have missed that @funkyjunky recently corrected us on the use of TCR in his Tubo thread
    http://fuckcombustion.com/threads/tubo-evic.22992/page-134#post-1316841

    Thank you @funkyjunky

    As I'm as guilty as anyone for spreading the misinformation I lazily picked up from skimming through this piece*, I am sorry for my laziness and misinformed postings on the subject and shall be posting from my new position on the naughty step for the next week.
    * https://www.ecigssa.co.za/guide-to-fine-tuning-temp-control-vaping.t18206/

    Basically we're doing it all wrong by changing the TCR to make it work, we should be using a TCR of 185 and adjusting the set resistance reading instead for better temp control.

    Instead of increasing the TCR to increase the temp of the coil we should be increasing the resistance (and vice versa, decreasing resistance to decrease the coil temp)


    Currently setup with 2x 316L SS Staggered Fused Clapton (2x 26/32 spaced claptons stagger wrapped in 32) 4.5 wrap (6x2mm) coils which came to about .14 ohms on the Invoke with sur_myevic. Performance is on par with the Super Claptons, using a tiny bit less power per bowl but still only 5 or 6 bowls from a full charge.
     
    stickstones, KeroZen and Hogni like this.
  2. KeroZen

    KeroZen Chronic vapaholic

    Messages:
    3,097
    Location:
    On Air
    No no, re-read what he said. We should definitely be adjusting the TCR to the materials we use. 185 works for the SS grade he's using but others might be different (there's a lot of variation even for what vendors call SS316)

    Also it's only valid for his custom firmware. With other mods and other custom firmware, you can't always trick the resistance reading and add any offset. In which case it's best to use the correct TCR and live with a temperature display offset (as long as your adjustment range is more or less linear)
     
    stickstones, Alexis, Hogni and 3 others like this.
  3. HerbieVonVapster

    HerbieVonVapster Well-Known Member

    Messages:
    777
    You beat me on the response with DNA you only lock OHMS if trouble reading core.

    Resistance lock: The DNA 250 relies on the cold resistance of the atomizer to measure temperature accurately. If the connection is not stable or if you find the measured resistance drifts with time, it may be desirable to lock the atomizer resistance. To do so, while locked hold both the Fire and Up buttons for two seconds to enter Resistance Lock mode. In this mode, the DNA 250 will use the present atomizer cold resistance without refinement until the atomizer is disconnected or the resistance lock is disabled. A lock symbol will replace the ohm symbol on the display. To disable resistance lock, repeat the procedure to lock it.

    I think it even more important with the DNAc not to lock than the DNA. Have to look it up but I seem to recall they tweaked this area in the c series.
     
    Alexis, KeroZen, Hogni and 1 other person like this.
  4. Hogni

    Hogni Honi soit qui mal y pense

    Messages:
    3,426
    Location:
    Berlin, Germany
    Thanks, Herbie but again please create an own thread with all the info on different sw and devices in a special thread - PLEASE! :bowdown:

    You are giving such great info but they all are so widespread on 5(?) threads it's dam' difficult to find them all again especially bc your statements had to change over time. It would be so much easier for all of us (incl. yourself) if you'd put it in one thread w/o the option to reply and you'd just overwork it if needed and call the updates of sw and statements.
    This way it'd also be easier for the other specialists to correct or give you additional advice and info.

    All the 510 attys CAN deliver an awesome performance but only if the settings of the mods are right. It only needs a lot of interested researches to get them most of us can't or don't want to invest. The more yours - and those of the other knowing guys - are really, really appreciated.

    Honestly, it would be more the job of Dan, Ryan and Alan to give all these important detailed info on "How to run my fucking device" on their own sites instead giving some info on their website, some here on FC, Instagram or even Instagram live streams, Youtube, FB or what social media else.
    Hey guys, it's your dam' job to do so for your customers if you want to have satisfied customers and good reviews on your devices. And you all let sit your customers in the dark and force them to do their own timewasting researches on these electronic things and following you on all fucking social media sites every time.

    Don't forget your customers just want to enjoy your devices and not to make a study on the secrets of 510 mods or even a timewasting hobby of it.
    Don't forget your customers only can get the best performance - or any - out of your attys if YOU show them the right way.

    I write this here on the StemPod thread bc Dan or better his device makes the most troubles and leave the most unsatisfied and frustrated customers. Of course, also bc he currently has the less developed heating tech. Dan, it's time for pioneering! :wave:

    For clearance, this is no bashing in any way just a rant out of deep frustration and a total lack of understanding of the ignorance of all you manufacturers. Don't get me wrong. We WANT to love your devices but we need YOUR help to do so. It can't be the job of @HerbieVonVapster @KeroZen @Summer and others to do yours.

    Hope you all understand what I mean? It's not so easy for me to explain exactly in English what I want to say. At least this was my longest post of nearly 3.500
     
    Last edited: Oct 21, 2018
  5. Brisirg

    Brisirg Member

    Messages:
    4
    I would say that the Stempod and maybe any other 510 adapters should be promoted as advanced vaporizers because the experience varies greatly depending on the mod one has and the knowledge about the world of the mods.

    There can not be fixed operating values because what works in one mod will not work in another. The value of the stempod is that is customizable and for that you must know terms like what is TCR, how to adjust it, how to build coils, etc. Things that are not for beginners.
     
    Last edited: Oct 21, 2018
  6. Hogni

    Hogni Honi soit qui mal y pense

    Messages:
    3,426
    Location:
    Berlin, Germany
    Correctly, but therefore we need some advanced basic info no one of the manufacturers gives us.
    And @HerbieVonVapster thankfully does some tutorial and gives some points of orientation to us.
     
  7. HerbieVonVapster

    HerbieVonVapster Well-Known Member

    Messages:
    777
    Good points I posted results at same time as learning some earlier post have outdated info. Or ways I found better.

    The best place to start is to understand the whats happening and how the variables we all are using effect the experience. Density of the load, type of screens you use along with the stem size effect the temperature readings.

    I strong suggest reading thread some if is a little outdated for DNAc but gives a nice overview of how things work.

    https://www.ecigssa.co.za/guide-to-fine-tuning-temp-control-vaping.t18206/

    Had a hell time getting this months new coils on not one of my better installs. Going mess with it later decide if want to try the other pair.
     
  8. Hippie

    Hippie Well-Known Member

    Messages:
    225
    Thanks @KeroZen and @HerbieVonVapster for putting me straight .... again :)

    Sooooo another, day another 3 or 4 builds :)
    Couldn't get Taiji or Alien wire working, they look like they'll work nicely in wattage mode but the resistance isn't changing so I think they're labelled incorrectly and not 316L SS so temp control is out :(

    So I now I'm using 200 316L SS Mesh .. a 1cm wide strip rolled as tight as it will go, flattened out and wrapped round the 6x2mm stick 3.5 times. It's super springy, awkward to work with and right on the edge of acceptable glowyness for me but it's working well so far.
    Not sure what to try next, it came on a roll 1cm wide and I have a few different grade mesh sheets too so I could cut a wider strip or wrap a 1cm strip round some wire in the centre to give it more mass and stiffness, and hopefully less glow.
    I'm gonna keep these ones on for a few days 1st, in the hope that the glow settles down after a few more cycles like some of the other coils I've made have.
     
  9. HerbieVonVapster

    HerbieVonVapster Well-Known Member

    Messages:
    777
    Info from
    https://www.ecigssa.co.za/guide-to-fine-tuning-temp-control-vaping.t18206/

    Stainless Steel (SS-316L) has a TCR value of 879 x 10-6 Ohm/°C, or 0.000879 ohms per change in degree Celcius (scaled to a 1 Ohm coil).


    When our coil changes from 0.50 Ohm to 0.55 Ohm, the change in resistance, DR = +0.05 Ohm. We can get the change in temperature by plugging into the above equation (or, in other words, by taking DR = +0.05 Ohm and dividing by the TCR times the initial resistance (0.50 Ohm))

    (0.55 – 0.5) / (0.000879 * 0.5) = 113.77 °C. In other words, our coil changed from RT (lets assume 25 °C) to (113.77 + 25) 138.77 °C.

    The TCR therefore gives us how large the change in resistance will be for a change in one °C. For SS 316L, each °C increase from RT will give a 0.000879 Ohm change in resistance, for a 1 Ohm coil. For a 0.5 Ohm coil, the change in resistance for each 1 °C will be (0.000879 * 0.5) 0.00044 Ohm; for a 2 Ohm coil, it will be (0.000879 * 2.0) 0.001758 Ohm.

    By reading this info got to wondering if a easier way to decide the TCR value would be to follow above example?
    That each cold coil ohm is equal to a 88 increase in TCR value? Seems a lot folks use around 200 range for TCR. If take a 2.22 omh coil times that by 88 comes out to 202.

    Somehow this seems too easy so tossing it out there to see if I'm missing something here?

    Edit...tried it on DNAc with last months super claptons there 2.5 ohms so tried TCR 220 and it ran like crap. It produced clouds but not not the quality I liked. One these coils the 316L material file works best.


    Not having much luck with this months coils. Wound a lot tighter and having some issue with reading the resistance. Not sure what SS316L Dan sources hopefully something like TEMCo or other quality source.

    This is one area when using mod in TC mode thats you don't want to use a lower quality 316L. My advice to Dan would be to decide on a good quality brand something like Temco, kidney puncher etc. Then use that only moving forward for the coil of month.

    If above is correct then it be much easier to set the TCR value. If good quality should be close to 88 tcr per ohm?

    Not a expert on wire here's info on other high quality wire vendors. I like TEMco since there made in USA and gets recommended a lot. Having said that I haven't tried it yet so..


    http://vapingunderground.com/threads/wire-quality-sources.310245/
     
    Last edited: Oct 22, 2018
    jardri, stickstones, KeroZen and 2 others like this.
  10. KeroZen

    KeroZen Chronic vapaholic

    Messages:
    3,097
    Location:
    On Air
    This emphasizes two things: 1) the need for a very good ADC, 2) the higher the initial resistance, the more precise the TC mode works.

    For 2) have a look at >> http://www.steam-engine.org/wirewiz.html and see how "TC precision" relates to the resistance. Using a lower gauge (larger diameter) wire makes the resistance lower, but you're supposed to compensate by using more wire. Both because we want more surface contact area and because we don't want the resistance too low. Unfortunately there is a physical limit as to what we can build on our limited deck space...

    For 1) let's assume the very simplified case that your mod can only TC from 0.0xx to 1.0ohm builds (which appears to be what the evic VTC can do) Say that they have the gain perfectly matched and can use exactly the full range. Then the ADC in the MCU can use its full resolution, from zero (no atomizer) to 1ohm (max input range)

    In the evic and derivatives, there is a 12bit ADC. 12bit is only 2^12 = 4096 possible values. So the converter can only distinguish 4096 steps between 0 and 1ohm. Each step is thus: 1/4096 = 0.000244ohm.

    So you see that at 0.5ohm in the example above, a 1°C increase is already 0.00044ohm, meaning our ADC can only count in less than 0.5°C increments. Any change below that value will read the same, as if there was no change.

    Now if you follow that reasoning, for a 0.25ohm coil, 1°C change is 0.00022ohm, that is already smaller than our idealized ADC can distinguish. For a 0.1ohm build it's 0.0000879 and so on and it gets worse and worse.

    I say idealized because it's not that simple, and it's likely way worse in practice due to noise, errors, drift etc...

    I tried to find what kind of ADC they use in DNA boards but I wasn't successful. I didn't even manage to find what MCU is inside. Would be nice to know, as I keep saying they have superior hardware but I have no proof of that (excepted they work well in practice...)
     
  11. jardri

    jardri Vapor Dreams

    Messages:
    321
    Hello gentlemen! I have made my first coils today with a screwdriver and a knife. I bought some 316 ss .20 gauge wire and I am extremely happy with the results. I use the stempod at 45W and I get even vaporization with a stirring at the end and very good flavour!. Coils dont glow at all during use and even though heatup time is a little slower I think the Stempod should come with them. They should be very durable but I will update when I change them. Only issue is they are 0,12 ohms in my current setup and I dont know how to setup TC in my new Wismec Reuleaux evolv DNA250 that i bought from a link in the mods thread. Could any of you give me some advice?
     
  12. HerbieVonVapster

    HerbieVonVapster Well-Known Member

    Messages:
    777
  13. fogbank

    fogbank Well-Known Member

    Messages:
    263
    I replaced my Eleaf iStick Pico + heat sink setup with a Joyetech eVic Primo 2.0 because I suspected that the heat sink was causing problems with temperature control. I just could not get the Stempod to behave consistently. Sometimes it would reach temperature and the Pico would "pulse" the power to maintain the temp (as desired), other times it would never reach temperature and the coils would glow brightly the whole time. And still other times it would reach temperature but the coils wouldn't glow at all, and I wouldn't get any vapor.

    It turns out that the heat sink was not the problem with temperature control, however I still would not recommend using one. The main difference that I noticed when I switched to the Primo was that I got almost zero airflow with the SP air holes completely closed. When I used the heat sink on the Pico I never opened the air holes and I got decent airflow. I think that the SP would not normally allow any appreciable airflow with the holes completely closed, so I think that somehow the heat sink on the Pico was letting air in somewhere.

    But the main problem with temperature control seems to have been how I was using the ArcticFox firmware, and how I approached handling the resistance of the SP in the AF profile. Before getting the SP I read a bit, and was fully aware that resistance readings should be done with the coils at room temperature. However I thought this only applied to the "initial" resistance reading that the mod takes the first time it detects a new coil. So I was constantly tweaking the settings in AF and powering the device off and back on when trying the new settings. At the same time I was "resetting" the resistance to .24 Ohms in the profile often.

    Somehow the combination of resetting the resistance (and locking it at times), testing settings, and powering the mod off and back on lead to really inconsistent (and frustrating) results. This happened on both the Pico and the Primo, so it was not related to the heat sink. So really I was frequently powering the mod on with the coils hot.

    Now I always power the device on at room temperature. I let the mod measure the resistance and I don't mess with it in the AF settings. I make changes to the settings with the mod powered on and I test them without power cycling the mod in between changes. At this point I have TC working as I expect it to, and the results are consistent. Hopefully it stays that way.
     
    Vape Donkey 650, KeroZen and Summer like this.
  14. supershredderdan

    supershredderdan Well-Known Member Manufacturer

    Messages:
    184
    If you want to cool the coils in a pinch between resets, just blow through the StemPod forcefully or take the body off and blow on the coils for a second, they will cool fast
     
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  15. TastyTicTac

    TastyTicTac New Member

    Messages:
    27
    Is there any way to load more at a time into the stempod? I’ve noticed that the mesh screens that I pre-fill run out fast (3 good hits or so) and I usually like to hit it for a long time period while gaming or something. Although i don’t necessarily have a problem popping in and out new screens, I only have 3 good screens and one that semi works (stepped on). Has anyone else found a good method to longer-term vaping with less hassle?
     
  16. Easywider

    Easywider Simple is the way

    Messages:
    182
    Location:
    Ontario
    @TastyTicTac You could pop in a S&B dosing capsule along with a packed stem to dbl your session or you could pack your screen like this:

    [​IMG]
     
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  17. Hippie

    Hippie Well-Known Member

    Messages:
    225
    There are some longer mesh basket screens you can use like the Vapexhale EZ load bowls too
    Sorry I can't find them on dhgate or alibaba at the moment but I know I've definitely seen them being sold by some of the crystal pipe screen sellers on there.

    The further away you get from the coil the cooler it'll be tho so you might have some issues regulating the temp throughout the bowl.

    As an alterative approach you could place your load on the screen and use a short stem or use the o-ring to hold a normal stem higher than we normally do, to pack more in.
     
    Summer likes this.
  18. TastyTicTac

    TastyTicTac New Member

    Messages:
    27
    Hmmmm... I might have to try that with my broken screen, I’ll try cutting it up today to see if it’ll work. I am concerned about even burn though, as @Hippie said. In the past I usually overload bowls and scrape off the burnt stuff anyway. The only problem with this method would be after scraping the cal empty you couldn’t scrape much more off too easily without potentially burning yourself
     
  19. jardri

    jardri Vapor Dreams

    Messages:
    321
    I have been experimenting with 0.20 gauge ss316 wire and I had success with 2 coils:

    The first one is an oversized 6-wrap coil has a good heat distribution when vaping but I think it wastes a lot of heat because the stempod got too hot.

    [​IMG]



    Then I decided to make the coils normal size but with 7 wraps. It was a little difficult because how thick the wire is but i managed to get a great heat distribution and though it seems to run cooler at the same wattage it distributes heat more evenly so I get the same clouds and better flavour and more hits per charge without charring. May we have a winner here?? It does not glow and it does not have metallic aftertaste:

    [​IMG]

    I am trying to configure TC in a non-dna mod for this coil but none tcr seems to work any hint?


    Changing subject I have noticed that if the coil gets orange hot, even if it is only once, the flavour gets some metallic aftertaste and it does not go away until I change the coil. Am I the only one noticing it? It affects greatly in tc mode as usual coils make a pulsing from none to orange red and I dont like the taste it gives.

    What I like more of this vape is that its basically the structure, you have to make the vape itself :science::science::science:
     
  20. KeroZen

    KeroZen Chronic vapaholic

    Messages:
    3,097
    Location:
    On Air
    For this gauge try a TCR around 180. That's what I usually end up with on other attys and in the Project for instance.

    To set up TC go to a dark location, like your WC with the light off, and start ramping the temp. Start low like 140°C. Once you see a very faint glow, note the value and that should be your max temperature. Then back down about 20°C and you should be in the zone.

    Of course with stock TC on the Chinese trifecta it doesn't work well and you'll see a lot of pulsing. But with AF and using device monitor it should be easy once you enable PI regulation. Or same with DNA but you don't have anything to enable.
     
  21. HerbieVonVapster

    HerbieVonVapster Well-Known Member

    Messages:
    777
    To set TCR in DNA mod.

    Click action button for pop up screen to enter TCR.

    [​IMG]
    Is it reading it as TC wire. Is the wire resistance correct?
     
  22. Hippie

    Hippie Well-Known Member

    Messages:
    225
    Set TCR to 180 ish and temp low at like 140 as @KeroZen says and increase the temp until it works ok
    From there you can adjust the TCR and temp, knowing the the coil temp increases as you increase the TCR
    If you don't like the rate of change of temp you can further adjust things knowing that coil temp will increase as you increase the resistance.

    I'm finding the metallic taste from the thinner wires I've tried fades after a few cycles and the coils settle down if they're not too glowy to begin with. The mesh I've had on this week was a little metallic tasting and glowy at first but after a few uses the resistance has increased a littlle, and the glow and metalic taste have faded.
     
  23. AJS

    AJS Calm Consistency

    Messages:
    2,662
    What is your guys' preferred method for the StemPod? I find I get an increased harshness with the fully open airflow when using it dry, so I tend to stick to water with the StemPod. I like that you can turn the temp up and just straight fuckin wail on it and the vapor keeps pumping out. I honestly don't know how Dan manages to get some of the hits he does, he is insane. I thought I could get some clouds but he really puts a number on me. I really need to setup TCR on this mod, I've been stuck using wattage mode as I'm too lazy to figure out the settings. It's so worth it though.
     
  24. jardri

    jardri Vapor Dreams

    Messages:
    321
    Im getting good clouds with mine hitting dry with the stock mouthpiece (which I think is perfect). I think most of your harshness problems may be with the coils, in one hand the stock coils are the worst i have tried so far and in the other hand the coil placement is extremely important to get a good smooth hit. In wattage mode you have to pull consistently and adjust wattage according to how fast you pull. I prefer a long slow hit so I can get very dense cloud with the airflow completely opened. With the same watts if i hit faster I get harsher vapor and less density so speed is crucial, too (experimented while writing ehehehe)
     
  25. sickmanfraud

    sickmanfraud Well-Known Member

    Messages:
    1,673

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