Boiler musing

I stumbled on the open source lever project thread on home barista the other day. The goal of these clever people is to marry an off the shelf lever group with the thermoblock from an ascasa to make a small-footprint commercial quality lever machine. A noble goal indeed. The upsides to this idea are numerous: no pump, very fast warm up time and all of the benefits of a microcontroller. The downside, as far as I am concerned, is the inherent complexity of the microcontroller and everything that it brings with it. Call me a Luddite, but I'm not sure that I want bluetooth as an option on my espresso machine. More importantly, aside from the difficulty of recompiling the code for the replacement for the microcontroller when it fails in x years, how long is the thermoblock going to last and how long are ascasa going to continue to make it? I own an ascasa and can attest that they are great for making an espresso (but not more than one) and it burnt out in less than a year of moderate use at the office. This is an admittedly small sample, but I think that it is safe to assume that ascasa has performed some value engineering given that this is a domestic machine with a one year guarantee. How many times has the boiler failed in either of the auroras that I use? Not once, as far as I know... in thirty years.

  

With the exception of a few transistors, diodes etc inside the Gicar water level controller and the electric pressurestat, the Aurora is all industrial revolution technology. The complexity and sophistication of the engineering is expressed in the selection, sizing and form of the materials that are combined to produce its desirable and highly repeatable temperature and pressure profiles. As a result of the thermodynamic design, the grouphead temperature is stable at idle and the HX circuit balances the heat gain when pulling shots. What fails first on these machines? The controller and pressurestat. 

While I am certain that there is room for improvement in the control electronics, I think that the Aurora should remain, at heart, a steam engine.