Here are some extra parameters, with acceleration enz.
The forces and torque in the base are going to pretty big, i have basic drawn the design in Solidworks and did a stress analyse on it. i can keep the stress nice spread and the maximal displacement off material (bending off the base by forces) = 0,000037mm
For forces that come from milling, friction from the thk rails and F=ma and stuff. i have taken 500 N. Milling isn`t taking any force because the maximum depth/width is 0,5 by 0,5 mm.