How to build CNC machine at home. DIY CNC mill build (part2) HD

How to build CNC machine at home. This is 2nd part of my CNC mill project. In this part I build X , Y and Z axis and roughly assemble them. For Y axis which is heaviest I will be using 20mm Ball screw and 20mm linear rail with square type carriage bearing. For x and Z same 20 mm rails but 16mm ball screw. Z axis will be very heavy but i have plan to build a balance system for it. Part1 video. https://youtu.be/CtWfcRgbRgU