When you plug your data in to steam engine for a dual coil build, it tells you a # of wraps to get your desired resistance. Is that number per coil, or total?
Using steam engine...
- Thread starter Hans Wermhat
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Welcome to ECF, Hans...
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Click the first sigline link below... start reading. PM me if you have any questions.
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I got it I think. If you add a 2nd identical coil, you halve the resistance. SO its total number of wraps for both coils, right?
Correct. For two coils in a parallel connection, the net resistance is one coils resistance, divided by two. If you have three coils, it's a single coils resistance divided by three. In any case of multiple parallel coils... the net resistance is the resistance of a single coil, divided by the number of coils.
If you look at the right box titled "Results"... and compare it to the value in "Target Resistance", the math is done for you.
I don't really think in terms of wrap count, because the wrapping mandrel you use will have an effect on the number of wraps. I look more at other variables, like net surface area.
This is what I was also wondering ...cool that you made this post
So if I select dual coil and then put all my info in ...my target ohms and it says 8 full wraps...is that 8 wraps EACH COIL or is that 4 wraps PER could with a total of 8 between the two?
So if I select dual coil and then put all my info in ...my target ohms and it says 8 full wraps...is that 8 wraps EACH COIL or is that 4 wraps PER could with a total of 8 between the two?
That would be eight wraps per coil.
If you give me your exact desired net resistance and wire gauge/type, along with the anticipated leg length per coil and the mandrel diameter... I'd be happy to confirm your calculations.
If you have a dial or digital caliper... I'd also like you to measure the actual wire diameter... it frequently doesn't match the SE reference, throwing off most all resultant values.
A few questions I have a re how do you know the leg length before you wrap it? Saying I do my wraps then put it into the atty and snip the excess...sorry if I'm getting it wrong it's my complete first build never tried it before I have tools but nothing I can measure the dia with I am going to wrap on a drill bit no doubt I want to aim for as close to 1 ohm as possible on a Aqua v2 by tobeco with 26g kanthol
Also not meaning to jack op's threadYou estimate the leg length the first time.. It'll be approx the center of where the coil will sit to the post. Steam defaults to 5mm, which are pretty close for most.
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26 gauge for a dual parallel coil build at 1.0Ω net... is too thick a wire, unless you use at least a 3.5mm mandrel.
On a typical 2.4mm mandrel, 26 ga. duals at 1.0Ω... that'd be 18 wraps per coil.
You need to drop down to 28 or 29 gauge - for a more practical and easier to heat with less wattage - at 9-12 wraps, depending on the gauge used.
Now... if this is a single coil, you're OK with 26 gauge.
You might want to take some time to read the article at the end of the sigline link below.
Information is information... if Hans doesn't need it, someone else will.
Leg length can be estimated, based on past builds. A dial or digital caliper, or a machinists rule can come in handy here as well.
26 gauge for a dual parallel coil build at 1.0Ω net... is too thick a wire, unless you use at least a 3.5mm mandrel.
On a typical 2.4mm mandrel, 26 ga. duals at 1.0Ω... that'd be 18 wraps per coil.
You need to drop down to 28 or 29 gauge - for a more practical and easier to heat with less wattage - at 9-12 wraps, depending on the gauge used.
Now... if this is a single coil, you're OK with 26 gauge.
You might want to take some time to read the article at the end of the sigline link below.
Exactly.
That's crazy. If I want a .5ohm build on my GA Rampage (3 coils) with 24G Nichrome I am looking at about 21 wraps each coil @3mm!!! That won't fit!!! Lol! I'm using an unregulated 2x26650 mod, so I don't want to push it any lower than .5 ohm (@ .2 ohm I am over the 20A mark. and I understand that even slight variances in the measurement can throw the calculations off).
If your box mod is dual 26650 in parallel, the amperage potential effectively doubles. For the latter comment, yes, at 0.2Ω you need to know what you're doing, and you need a accurate Ohm meter/build box.
Speaking of accuracy... USA Ohm Meters recently came out with the handy "Fire Meter". Not cheap, but it is as accurate as all the other USA meters... and they are, for the money, some of the most accurate meters you can buy.
You haven't got a good grasp of this yet. For three coils, the resistance NEEDS to be lower. You need more power from your unregulated mod, because there are TRIPLE the amount of coils. So .5 ohm is not going to work. With two 20A CDR batteries in parallel, each battery is going to see half the load, so you can build almost all the way down to .1 before hitting the rated continuous discharge for those batteries. So if you are not prepared to build low, then start with a single or dual coil build and you don't need too. So I'm not saying that you should try this low right away, but I am saying that .5 ohm with 3 24g coils is not going to vape. It will barely heat up...
ETA: If it was my tri-coil RDA, I would do it with 24g around a 2mm screwdriver. Six wraps per coil, microcoils. Proabaly would ohm out to somewhere around .15
I have been building sub-ohm on dual coil drippers for almost a year. I never really cared much about the actual math behind it until recently when I decided to give nichrome a whirl, but I have never had a problem building a successful pair of coils. I was using 26 and 28G Kanthal without any issues, but wanted to make sure I didn't over-amp my batteries when I started using lower resistance wire. I like the nichrome because there is less ramp-up time and I can build coils with more surface area. My dual coil builds all read just over .2 ohm. (6 wraps @ 3mm), but my meter broke the day before I got my Rampage, so I checked steam engine to see what I should be looking for. I discovered that it is way too much info for me. Lol! I'm learning though.
I built it 3 coils @ 3mm with 4 wraps each. It fires instantly and is actually too hot. I plugged it in to Steam engine and it says it should be around 0.1 ohm. My ohm reader is broken so I am using my Fluke multimeter and it reads .15...but I don't trust it completely for this type of application. The probes just don't make as good a connection as a proper ohm meter.
Space in my Rampage is limited. 6 wraps with 24G doesn't fit well. I would have to bend the legs back around a couple of the wraps to get back to the terminals. That's why I went with 4 wraps @ 3mm.
my suggestion was using kanthal. Nichrome is a lower resistance wire, so your ohms will drop just with the nichrome. ie: wrapping around 2mm, 6 wraps kanthal = 8 wraps nichrome.
So, on this tri-coil build, it would be easier to fit without going too low using kanthal.
But I bet that your same 3mm build would work fine with just one extra wrap per coil, so 5 wraps each. Then open the airflow and use the wide-bore cap that the RDA comes with. Sounds awesome.
I am pretty sure you could easily fit 6 wraps in there though, especially if using a 2mm wrapping diameter. You can use any of the wire holes in the positive block for each coil. ie: you don't need to pick the one right next to the negative post.... you should pick the one farther away. And center your coils on the airholes.
So, on this tri-coil build, it would be easier to fit without going too low using kanthal.
But I bet that your same 3mm build would work fine with just one extra wrap per coil, so 5 wraps each. Then open the airflow and use the wide-bore cap that the RDA comes with. Sounds awesome.
I am pretty sure you could easily fit 6 wraps in there though, especially if using a 2mm wrapping diameter. You can use any of the wire holes in the positive block for each coil. ie: you don't need to pick the one right next to the negative post.... you should pick the one farther away. And center your coils on the airholes.
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I'll have to give it a try. Time to hit the b&m for some kanthal. I love the chuff tip it comes with, except that its thin and feels kinda cheap. It was a cheap clone (like $17) but from what I hear the authentic is about the same and the machining leaves something to be desired. The umbrella was the biggest selling point for me. No more spit back blisters on my tongue. It vapes really well. Air flow is just about right. I just need to play with it a little more, I guess, until I get it right. Will definitely try the kanthal though. Should I stick with 24G or go for 28G and more wraps?
If it was mine, I told you already how I would do it. 3 24g kanthal microcoils around a 2mm screwdriver, 6 wraps each, using the farther away positive block holes to mount the coils directly in front of the cyclops openings. I might even drop it to 5 wraps each, but definitly no less than that. But I would do this with the airflow wide open and using the chuff cap, which will keep everything much cooler than with a 510-sized drip tip.
I wouldn't build my own RDA this way, but if you wanted a suggestion using 26g kanthal, then I would do three coils exactly the same way with the 26g (same diameter, same # wraps). The resistance will be higher, but thats ok because this wire is less massive and doesn't need as much power. 28g is too small for this cloud-chasing RDA.
I wouldn't build my own RDA this way, but if you wanted a suggestion using 26g kanthal, then I would do three coils exactly the same way with the 26g (same diameter, same # wraps). The resistance will be higher, but thats ok because this wire is less massive and doesn't need as much power. 28g is too small for this cloud-chasing RDA.
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