Br, if you extend the tube another 3/4" and tap some threads on it, then
cut the carto about 5mm below the bottom of the cup, and tap some threads on it, you would
have the one I was thinking of earlier.
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Here is another thought:
Once the wick leaves the cup, what if you really don't need a wick? I mean at least not a stringy wick, what you could have is a hollow, tube-like wick that would essentially line the carto wall.
The current coil wick (now just a 1" wick) would get the liquid off of this tubed wick, and the tubed wick could be built into a plastic cartridge frame that could be easily replaced.
Since the carto top now ends just below the cup, even the cup could be replaced if they also sold the repair parts such as in quantities of 25 or 50.
Even the coil wick could be easily replaced, since it's only a 1" wick if the tubed wick frame cartridge replaces the wick loops inside the carto.
I'm not saying this could be the next version, because we still want some current version in the meantime, but what if this works and allows people to simply replace the gunked parts eventually?
Even then, they could easily carry both versions:
Version A =some kind of the current version, that people can throw away at the end of the day, and
Version B =the one where the hood comes off, and can be made to last for months.