Precision Piezo for Modular X-carriage Flex3Drive module

Piezo disk assembly for the flex3drive module for [modular X-carriage](https://www.thingiverse.com/thing:2039960). Intended to be used with Precision Piezo electronics and disk.

1. print
2. secure the piezo disk in the flat ring (20mm piezo disk holder.stl)
3. flat ring goes directly under the Flex3Drive-xxx.stl
4. then the cone (20mm piezo disk cone.stl)
5. and the the rest of the assembly of the module goes (the hotend clamp from flex3drive, shroud etc..)