Advice for an SVD with an Orchid v4

[Quicksilverw]

I'm a long time lurker but new to the site; I've just recently purchased my first rebuildable and I'm hoping to get some advice from you guys. I've got an Orchid v4and I've built 4 coils so far:

Build one was a dual coil with each coil being 10 wraps of 28g - final resistance 1.0 ohm. Build two was a dual coil with each coil being 11 wraps of 28g - final resistance 1.1 ohms.

Both of these builds were good; the flavor was great and the vapor production was nice and thick. The problem with both of those however was that it took forever for the coils to heat up. I was almost having to fire it until I could hear it sizzle, release to reset the cutoff timer, then re-fire to vape (this wasn't as bad if I chain vaped to keep the coils warm for several hits). I thought the problem may have been coil diameter. Builds one and two were both 1/8 inch inner diameter. I know that the gauge and length of the kanthal are what determine resistance and that a larger diameter with fewer wraps should be roughly equal to a smaller diameter with more wraps given the same gauge wire...but I figured maybe it would somehow make a difference.

So...build three was halved to 1/16 inch inner diameter with 15 wraps per coil. The final resistance is 0.8 ohms BUT when I test fired and counted its still taking 4 to 5 seconds for the coils to glow.

Finally, I figured that I would purchase some 30ga as the higher resistance would allow me to use less wire for the same resistance which, in theory, should be easier to heat up. My 30ga build is dual coil with each being 6 wraps loosely spaced (all m other builds were micro coils with no space between wraps) and a resistance of 1.1.

I'm still having the same problem...the coils take a sec before they get hot.

I'm starting to think that the SVD isn't fit for a rebuildable. Any thoughts? Suggestions?

 

[State O' Flux]

Welcome to ECF, Silver...

The "heat capacity" of your builds are too high a value... producing slow heat up and cool down times.
Refer to both my first and second sigline hyperlinks. The first will take you to the Steam Engine program, the second will take you to a Steam Engine user guide... that will explain things like "heat flux" and the previously mentioned, heat capacity.

Also, the SVD has a lower resistance limit, based on maximum wattage and current output. The former is the value you put into the heat flux wattage variable... that will calculate both the above values.

While you're clicking links... might as well take a look at the last hyperlink below as well. Can't hurt. ;-)

Cheers

 

[Quicksilverw]

After playing with the calculator it seems like the only solution is going to be to go with at least 32ga. kanthal.

 

[State O' Flux]

After playing with the calculator it seems like the only solution is going to be to go with at least 32ga. kanthal.

That happens more often than you might imagine... when the power supply output wattage is limited.

 

[v1k1ng1001]

The SVD is not really the device you want powering a rebuildable. It's not only underpowering the orchid but slower to power any coi because of its pwm output. You've done a good job of pushing it to its limit I'd say.

I loved my SVD but, once i got into rebuildables, went to mechs for a year and now I'm running a 30w vv box. Donated my SVD and Vamo to a friend who was getting started.

You can pick up a cheap mech clone (always good as a backup) but, these days, I'd say shop for something in the 30 to 100w range--preferably with an evolve or yihi chip. You'll appreciate the power and output signal on a dual coil rba. Sigelei and IPV seem to have some nice offerings that are not cheap but fairly priced.