Improvement proposal

It would be interesting to modify the mounting of the screws on the X and Z axes.
In the current assembly, axial forces are supported by the motor bearings, and the mounting is hyperstatic (X / Y / Z locking on the motor side, X / Y at the nut and Y / Z on the bearing).
It would be more "mechanical" to make an assembly similar to what is done on the Y axis on the side of the belt (2 bearings which ensure the blockings according to the 3 axes) and a flexible coupling between the motor and the screw.
This would make adjustments easier, sparing the bearings of the motors, without causing an extra cost (1 bearing, 1 washer, 1 nut and the screw 10mm longer).

On the HF spidle control unit, it should be usefull to add an DB10 connector to be able to use easly Tool Length Sensor and 3D touch probe (or as I've made, install a connector on the front side).

I hope that these ideas could help to improve a little more this machine already very nice.

Olivier.