Current prototype specs:
- Commercial spring lever group - I purchased a Victoria Arduino (Bosco style) group - $495 USD - alternatives could be San Marco, CMA or Conti
- Dual Ascaso Stainless / Aluminum 1000W Thermoblock - cost about $25 USD each
- Plumbed in
- Steam thermoblock (or boiler) will operate with a steam-brew priority switch. In brew priority the steam element will not operate when the brew element is on, and vice versa.
- Arduino + TC4 shield for PID control - Measuring Brew TB, Steam TB, Mounting Plate Temp, Group (side)
Few other operation remarks:
- I've programmed a "SHOT" guessing temperature, so that you can see what the controller predicts shot temp to be (based on TB and Group temps). This is being confirmed and tuned now with a Scace.
- Flushing or moving setpoint of the TB can alter the shot temp very quickly. Like the flexibility of an HX with the stability of a DB.
- Preinfusion pressure is set with a regulator, but during heat up pressure builds inside the system. Generally a small quick flush relieves this pressure and then the shot is pulled.
http://www.ascaso.com/2012/eng/espresso ... ream2.html
Current prototype machine:
Index of Other DIY Builds:
La San Marco Open Source Lever Machine
DIY Dipper Lever
From Scratch DB Home Lever
'Huxdible' - a 2 group HXDB lever project