HyperCube Evolution X-Carriage Integrated Piezo

Overview
========
This is my new X-Carriage Hot end for my Hypercube Evolution. I'm using a piezo disk in the carriage like in Pumpal's design https://www.thingiverse.com/thing:2801604. But I didn't like how big the X-Carriage became so i redesigned it.

I'm using the [Precision Piezo Piezo20 module and a 27mm disk.](https://www.precisionpiezo.co.uk/product-page/copy-of-piezo20-pcb-for-the-piezo20-module-1-piezo)

My design principles:
- use of Piezo in carriage so no separate piezo in tools
- keep ability to change tools
- as compact as possible
- use standard e3d cables and connectors
- one fixed cable from carriage to back. Connectors on carriage.
- 10mm carbon rod & Igus bearings

For a adjustable dual hot-end mount see https://www.thingiverse.com/thing:2990907

Assembly instructions
=================
[WIP]
Most parts are being connected by 3mm screws and brass inserts. The the end stops and the Piezo20 are mounted with 2mm self-tapping screws.

Some parts are