OK here's what I have so far. I'm about to get back to work on it but I wanted to post these before I forget.
First, here's what the back of the circuit board looks like (please ignore the crappy soldering job). The important thing to note here is that there are four pins in the regulator, and four vertical columns on the board, so connecting to any of the spots down that line is equivalent to connecting to that pin on the regulator.
So the first thing I did was put the pins of the regulator in to the holes at the top of each of those columns, then carefully bend the pins so the regulator lays flat with the board (I had to clip a few mm off of that end of the board so it could lay flat)
Now here's the schematic from madvapes, the only change I made was to add the resistor + LED in parallel between Vo and the ground. And as a minor point, the switch comes before the battery, but that doesn't really change how I did anything.
So since we have these columns to work with, everything becomes pretty simple and you can handle each piece individually instead of worrying about soldering a whole mess of wires together.
One last thing before I go in to the details, this is NOT the exact process you should follow. It should really be more like the 2AA box mod tutorial that Hoog has up on the site - first you drill your holes, then you mount your components (except the board), THEN you solder, and finally mount the board to the box. But since my drill wasn't working and I'm impatient, this is how I did it. But I'm going to have to redo a lot of the soldering to mount everything properly and trim wires. So this should really only be a general guide as to how the circuit comes together.
In this next picture, you can see what the regulator looks like from the front. From left to right, I refer to these pins, and their entire columns under them, as pin 1-4 (brilliant, right?) Pin 1 is Vin, pin 2 is Vout, pin 3 is ground, and pin 4 is control(disable)
So first, connect the negative lead (black wire) from the battery box to pin 3 (I am holding the wire between my fingers):
Next, the positive lead (red wire) from the battery box to pin 1 (I am holding the wire). Obviously the terminal is not mounted in the box right now. When you move the last terminal in to its proper position it doesn't fit very snugly, so that will have to be well secured at the end to handle the stress of constantly replacing batteries.
A 470 Ohm resistor goes between pins 3+4 (I'm pointing at it)
Make a connection from pin 1, to the switch, to pin 4:
Make a connection from pin 2 to a 470 Ohm resistor, to the LED, to pin 3 (the resistor and LED are not yet soldered in this pic)
Make a connection from pin 2 to the positive end of the atomizer connection, then negative of that goes to pin 3:
So at the end, we're left with this little mess here:
That's about all I have at this point. The circuit works great for me, even though I look like a fool holding wires together while trying to press the switch and take a puff from it, but it definitely feels like 5V to me!
Here's sort of what I want it to look like when I'm done:
Note that the area in the bottom left of that picture should probably be cleaned out with a dremel or equivalent so the regulator can get mounted down there. It kind of looks like a tight fit in that picture but it's really not, there's plenty of room to work in this box.
Hope that helps somebody. I'll be back with more when I finish.
