After a month or so break my printer is up and running again with a new J-Head nozzle, which so far has been behaving extremely well; my first task has been to print off the parts for a new Herringbone extruder. The extruder I've been using for the past couple of months was an experimental one printed from my original Adrian's geared extruder and like many other experimental technologies its had its fair share of problems. It's done its job well so far though, and with some calibration has been printing its replacement parts well:

I'm also in the process of building a heat-bed, the design of which I've stolen from Auzze. If it works well then it should allow me to start printing ABS and should also reduce some minor warping problems I've seen with PLA:

One other thing I've been quietly experimenting with in my spare time has been trying to make a working extruder hot-end using parts sourced only from local retailers and requiring no specialized skills or equipment other than a hand-held cordless drill. The motivation for this has been driven partly by my recent hot-end failure and a corresponding determination to reduce my dependency on the relatively small number of people that sell these parts online, but it's also a first step into an area that I'm hoping to experiment more with in future.