Once everything was disassembled, I had a good idea how all the parts worked together. Next was the fun part. I got to design all the extras that I wanted to to have in addition to the normal function of an espresso machine. The only thing that limited the imagination was physics and the budget, so I decided to design a three phase system to separate the major jobs of an espresso machine. I designed a specially heated reservoir to feed a finely controlled hot water boiler for the espresso shot and a secondary boiler for isolated steam production so that both functions can be run without interfering or adding wait time to heat or cool the system. Implementing these designs would be the tricky part.
With David Schomer's ideal espresso machine in mind, I started by adding the first of three PIDs to the Rancilio, which is a common enough mod. RTD rather then a thermocouple This provides the +/- 1 degree control and instant water temperature read out that I needed for this project. I also knew I wanted to be able to see the pressure within the Boiler to be able to adjust the overpressure valve to allow the pressure to be constant throughout the entire shot. A short time and a few bucks later, and two pressure gauges solved that.
Stay tuned for next week as I continue to unveil each step taken to making this machine reach its full potential!