Nils,

Wow what a start! I think this introduction has first place position as the best example of a new comer, doing their much needed research first and then presenting to us a damn fine example of what is here on the forum learn from, be inspired from and then made into a reality.

I think if you build this machine to what is suggested in the CAD models and it finishes mechanically sound with an Electrical setup to the same standard, you'll finish with a flawless very capable machine.

The ONLY thing I think you should consider and do, is to move the Y Axis (Longest Axis, the bed) motors to outside the machine frame, I think their current location could give you a risk you don't need to take, first they could get in the way of the Z Axis accidently causing unnecessary damage, they may also be in your way if you decide to start using a coolant system as they could get wet and soiled and for woodworking, they could end up covered in dust, motors get very hot, internals could become clogged up/dirty.

Other than that I think you have a winner - GET CRACKING !

Lee