This mod looks like it might perform well, judging from the video... However......
From an engineering design point of view....
Complexity for the sake of complexity doesn't always a good design make, unless you are trying to win a Rube Goldberg competition. As the old adage goes, the simplest solution is often the most elegant. That was my first reaction when I saw this mod.
Adding complexity - such as in this case - also adds additional points of failure. I have to look upon it with a skeptical eye, unless it can be shown how this mod improves performance over much simpler bottom fed box mods.
Things to ponder when it comes to additional cost, complexity, points of failure, replacement parts, maintenance, safety, and everyday use:
1) A micro pump - complexity and point of failure.
2) A tube that sticks out (how will this effect it's transportability and everyday use?). Another point of failure.
3) Custom parts - like the tube and the piece that fits between the atty and mouth piece.
4) USB charging circuit. Will this charging circuit conform to battery manufacturers recommended CC/CV charging algorithm/profile (for both safety and longevity of the 18650 batteries?) Charging L-ion batteries has inherent safety risk/concerns (overcharging, thermal runaway etc.) Does this design address this? How about liability? Has end use been considered in terms of safety and liability? For example, will an end user leave this plugged in in the car to charge the battery (a USB charging port makes it seem like a convenient thing to do)? Would that be a good idea on a warm summer day and would one want to accept liability for it? In my view, the built in charging capability adds little in convenience when using a battery with the capacity of a 18650, and what convenience it does add is not a reasonable trade-off if it doesn't perform its task correctly and safely. It's even worse if it enables/encourages use that could be unsafe.
5) Variable voltages. I'm dubious about their necessity in the first place, and would not accept the trade off in complexity, cost, and an additional points of failure for the dubious gains that this feature might provide.
6) Buck/boost regulators and resistor bridge networks - adds more unnecessary cost, complexity, and points of failure.
7) Cost benefit analysis. What's the additional cost going to be over more simpler designs (especially if simpler designs work just as well or better)?
In my view, design goals for application such as this should be to make the device as simple, effective, and robust/durable as possible. The design should be as safe as possible, perform well, be easy to use, be convenient and easy to carry around, require little to no maintenance, and minimize unnecessary cost/complexity. Remember the first goal in this endeavor is to provide a replacement solution for the simple act of smoking a cigarette. That suggests that the solution should endeavor to come as close as possible in simplicity and convenience as the thing that it is trying to replace. Aesthetics, is another issue and the value of which is in the eyes of the beholder. If one likes a design - say for it's artistic value or that it's a nice looking piece of woodwork - than that's a different matter.
Sorry for being a downer, but that was my honest initial reaction upon seeing this mod for the first time. Perhaps I missed something and could be enlightened on it benefits.
