It's been more than a year since I last worked on this project, but for writing building instructions I redesigned it to be a printer add on, so that you can fit it on your own 3D printer, plotter or CNC machine.

I again fitted it to an Ender 3 3D printer.

On the pictures you can see that the build is made of the tubing for four colors, two SLA printed parts, four pumps, four filters and some electronics.

The machine is powered by an external 36V power supply which is directly wired to the H bridges, stepped down to 4V for the pumps and stepped down to 12V for the printer controller.

The printer controller controls two stepper motors and sends i2c commands to the Arduino UNO. The UNO sends signals (and 5V power to power their logic circuits) to the H bridges to drive the piezo discs in the printhead which eject ink droplets.

Hope this pictures help you, if you are interested in the project and want to build it.