What is the RepRap shot glass tradition?

That was started by a Kiwi - Vik Olliver. He designed the glass, which is easy for the machine to make and which allows us to test things like how much overhang we can build unsupported. Now anyone who makes a machine starts with the glass, and toasts the new machine in that glass that it has made for itself.

How will RepRap 2.0 Mendel differ from the Darwin 1.0 design?

The two main differences will be:

Firstly, it will also build with an electrical conductor, allowing the machine to make its own (and other) circuitry. This may even include simple electric motors.

Secondly, it will have a range of material write heads that it can pick up and put down automatically. RepRap 1.0 "Darwin" has two fixed heads, allowing it to work with two materials simultaneously. Mendel will work with half a dozen or so at once.

There will be other technical differences, like we may change the microcontroller that the machine uses, and we may switch from using stepper motors (precise and simple, but low efficiency and expensive) to servo motors (clever control needed for precision, but high efficiency and cheap).

How far away is RepRap from producing complex electronics like a mobile phone or an MP3 player, or glass and metal objects?

If you want 90 per cent of a mobile phone or MP3 player, and are prepared to buy the other 10 per cent (essentially the chips), then pretty soon (maybe four years at a guess). Ten years to being able to do the lot.

Glass needs high temperature, of course, so that'll take a while. But the electrical conductor we'll be using is a metal. It's called Field's metal and it melts at 60 degrees C.

Is the Darwin 1.0 design ready for anyone to access and build their own RepRap?

Companies are already selling kits. The design isn't quite finalized yet, but is close enough that hackers are happy to build one in the knowledge that they won't have any major changes to make when we do our first official release. The machine works at the moment, and as it can make parts for itself it is particularly easy to upgrade...