Arduino · Automation · BZ13 · Espresso · Hack · volumetric

zhng the espresso machine

“Zhng” (Verb) – an action to modify, usually used to indicate the intention of vehicle modification.

I’m a software engineer and computer scientist by training, hence I love the challenge of solving technical challenge. Recently, I’ve started experimenting with various ways to measure extraction of espresso. This photo shows a flow meter placed between the pump inlet and water tank for the Bezzera BZ13 espresso machine. This is based on the original design of the volumetric version of the BZ13 espresso machine. The original schematic is available from Bezzera here. The reading is managed by Arduino, a micro-controller which is cheap and is a good platform for churning data from sensors.

As this machine uses vibration pump, having a single flow sensor might not be accurate in measuring the total extracted espresso due to the water lost in the over pressure valve (OPV). An additional flow sensor was added to the outlet of the OPV to measure the water which returns to the water tank (not in photo).

160220-094401-07

Ultimately, I want the machine to perform accurate and automated volumetric extraction. The volumetric BZ13 espresso machine allows the barista to register only up to 2 volume settings, this limitation can be circumvented by replacing the buttons with mobile apps.

More tests have to be conducted, and the results will be shared in a post in future.

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