This is just barely electronic - unless you count the coil of resistance wire in the cartomiser. As a project, its far from finalised - so far the skill of winding a completely successful resistance coil has eluded me!. The main "bright idea" for a rebuildable cartomiser is to use a 2ml syringe for the body, the threaded insert stripped from an old Vapourlites cartomiser is a pretty good press fit into the end of the syringe body. The resistance wire was culled from a WW pot from the dynamic convergence panel on a delta-gun CTV, several pots were destroyed before finding the right diameter resistance wire - several online vendors stock the proper stuff. The wadding and wick material can be salvaged from a scrap carto, but is probably also available online. None of the fluxes in my toolbox enabled soldering of the resistance wire, the only option was to bind the tails onto stalks made from thin solid wire, and solder those to the screw fitting. The design of the Vapourlites cartos seems to be continually evolving, some versions have tiny solder tags for attaching the coil. My first attempt worked - sort of! If anyone figures out how to make resistance coils as good as the manufactured ones, please let me know.