KZ's experiments #003 - 20AWG AISI 304 SS "Clover Leaf" coils in Cali RDA
I went back to the Cali RDA and this time tried to build some coils with loops covering the entire width of the air intakes. I used some 20AWG 304 SS wire from "the Crazy Wire" shop in the UK (I ordered the smallest bobin and they sent me 50 meters, I have enough to build coils till the end of time heh!)
This wire was very easy to work using pliers and my hands, very little spring, stays in place well. I did something that looks a bit like clover leaf FPV antennas... Or well, let's say it's what I tried to do as it was a bit crappy and nothing super fancy and the pictures don't do them any justice...
You can see some color change but I had a few shorts while testing, this explains the non-uniformity. Afterwards and during use, the coils never became red, this is a good point.
For some reason I can't really explain now, the resistance didn't change enough during use and the box kept kicking out of TC mode and back to power mode. So I had to use it in power mode and went for a conservative 20W output. This time I got a very good session. It took a couple blank draws to get it started, but when everything became hot and going I got good vapor.
I still had not really a hot spot but let's say a darker band, because my coils were not symmetrical and when seen from above I could clearly match the coil geometry to the dark band geometry on the bowl material. Nonetheless the taste was not spoiled like it is in the "Project" when it creates that very focused and concentrated hot spot. In fact taste was good until the session was almost over (stirred once afterwards)
The session was pleasant but the RDA became really hot at the end, same for the stem base. The heat also transferred to the box mod body. It was not burning hot but not far, I could only touch the RDA for a couple seconds before having to remove my fingers. The fact that the inside is shiney should be a plus for heat reflectivity (mirror effect) but this steel mass is as expected stealing a lof of calories. It does give some back and creates some inertia like in the Mi/Zi, as I was able to keep drawing for a few seconds after letting the trigger go and still got vapor.
The walls and base of this RDA are relatively thin, so there's not a lof of mass. But the top part where the mouthpiece is with the fins is quite heavy. It's also tapered inside and that limits the space that you have to build in. You have to be careful with the top part of the coils otherwise they can touch the walls of this upper part.
Overall this experiment was rather a success but still far from the Holy Grail.
KZ's experiments #004 - MKWS Alien SS316L "Mountain Trail" coils in Fishbone RDA
This time I used SS316L "Alien Wire" (0.3*0.8 flat + 32GA, SKU 4625600) from MKWS, which is pricey but so good looking and sexy. I did two parallel coils looking like a trail climbing around a mountain top... or a pair of lungs if you have a lot of imagination!
The uneven discolorations are mainly due to partial shorts as I was adjusting the coils while dry firing them. The wire is nice to work with but more springy than the previous one, so the tracks had a tendency to touch each others and it was hard to confine them such that they don't touch the outter glass body.
I ended with a 0.28 ohm build that works well in TC mode. I used it several times and it's still what's inside my Fishbone right now. It works well, no hot spots but it has some inertia. It takes some time with blank hits (one or two at least) before getting any vapor, but once it's going it's good. But it takes time to reach temp (at least with the TCR settings I tried) Once to temp (ie. protection mode) it doesn't draw much (about 7-10A). I limited the Watts to 40 like for the Project for the initial ramp-up.
I got quite some giant cloudage with this setup and I still have to tweak the parameters (temp and TCR) to improve it, but I'm really satisfyed. Airflow is good, the RDA is compact and discreet/stealthy. Only drawback is that the glass will get really hot at the end of a session. But if I do a smaller load and take a few spaced out super rips, it's perfect. There's quite some inertia and I can continue drawing with trigger released like in the Mi/Zi.
In retrospect, I think we can't avoid the heat buildup (unless we use a very good insulator like wood) All my portable vapes become pretty hot during a session, especially conduction ones. Heck, even my Firewood becomes super hot near the bowl, Zion and Milaana too. On the FlowerMates the heat is less intense because the entire shell acts as a radiator (it's aluminium) But in our case we only have a very small surface area to radiate it out, so it's concentrated.
Even if it's bad practice, I found that by not screwing the RDA fully I could limit a bit the amount of heat transferred to the box mod. But it's at the risk of bending or damaging the 510 port. I also found that my coils still create too wide of a tunnel as I can directly see the air intakes when looking from above, so next time I will experiment with a better geometry (this one was the easiest to build that I could think of)
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Excellent construction. Opens up crazy schemes. A screen could be placed mid way way in the m-m adapter and invert a second one attached via clip, screen and O ring between. Could hold one hell of a lot of goodness.
![:\](/i/s/hmm.gif "Hmm :\")
