Aluminum router build - Could use some input

[Jonathan]

If you want to go down the FEA route, then make sure you get the boundary conditions right - for example it looks like you've got the X-axis bearings on round rails, but constrained to the rail not free to rotate. Also, you've applied a force to the spindle mount and fixed the machine base, but it's the deflection between the spindle (tool) and the workpiece that matters - so draw a block of material on the machine bed and constrain that.

Co-incidentally I've just been working out stiffness (torsional and axial) for ballscrews including the bearing mounts - the cheap 16mm ballscrews get around 50N/um. That's an order of magnitude greater than the stiffness of the gantry, so it could reasonably be neglected.