CNC mini mill Z axis rebuild part 3 

Regarding your holes lining up... That's why you securely clamp all the pieces together first, in their proper positions, with everything perfectly aligned. Then while it's all clamped together as one unit, you drill through both pieces at once, all the way through the first piece, down into the second piece. This results in the holes in both mating pieces to be perfectly aligned.

Good to have a second milling machine to modify the other one :-)

Thanks for sharing. Cheers

OK, thank you