In response to Breaktru's requests for more user input, I've finally got around to posting about my vv box. There's nothing very exciting here, but some of my mistakes might be instructive for other novices!
I've made unregulated wooden devices before, that worked well, but had been hesitating for months about doing a vv mod, for fear of toasting the circuit boards. In the end, with the help of an Ebay Hakko clone temperature controlled station, the soldering was the least of the difficulties. The hardest thing I found was to fit the bits and pieces tidily into what is probably a relatively large space , but one that feels very small.
As the layout shown was my third attempt, I did get a bit tidier through experience - The first go was with an OKR board, which was a bit messy but worked fine when first tested. I was overkeen with the epoxy though, rendering the pot adjuster immovable, and had to strip everything back to bare components and start again. On the second attempt, I fried the board by shorting to the body while testing.
Third attempt therefore used a freebie ptr08100 board which needed caps, so was more awkward to fit, but now works fine. I managed to get everything to fit snugly together without epoxy this time, except for gluing a small ledge for the meter to sit on.
The 510 connector was one I bodged together on my woodturning lathe, with a spring loaded pin sitting in the white delrin lower part. Switch is from Conrad and is the same, or
very similar, to the Altsmoke BB one.
The inside of the box is lined with plastic and perspex, for snugness and to prevent accidental shorts
A mistake while planning which box to get was to completely overlook the impact of the corner bosses - The atomiser and switch are therefore a bit more cramped than I'd imagined. There's no substitute for having actual parts in the hand, rather than the in the head.
One detail I was pleased with is the use of the springs as connectors, eliminating some wiring. By unwinding the Silver Bullet springs a turn or so, they could be connected directly to the adjoining terminal at the bottom of the pic, and to the 510 fixing nut at the top.
Overall, it works well. I have to keep an eye on battery levels though - several times they have discharged unevenly, with one going down to below 2.5v, while the other is still well over 3v. (Would I be right in assuming that the over-discharged cell shouln't be used again?)
I have to say though, that I'm a bit disappointed in the feel of the square sided box in my hand - Having made wide non-tube wooden battery holders before (see pic below), I thought that the metal box would be similar, but it's not as comfortable as my oval woodies. A future project may be to put a fixed resistance OKR board into an oval dugout wood device. - I definitely couldn't make the components used here fit in a more confined space.
