In the last few weeks I have built a CoreXY Printer for the toolhead.  For the axes I used the same 2020 wheel system like on the Ender 3 to keep the design as easy as possible.

The printer is controlled by an Arduino Mega 2560 + RAMPS 1.4, which controlles an Arduino UNO via I2C, which controlles five L298N H-bridges, which drive the piezos.

The toolhead is made of 40*40*20mm POM blocks, which are individually assembled and later mounted from the backside with a M6 scew on a 3mm steel plate.

For flushing the toolhead I have added a sink where the toolhead can be parked and flushed. 

The mechanical and electrical parts are working fine but for pressurizing the toolhead I must find another solution.

Maybe something with check valves or so...