last bit of simulation nonsense for today.
I increased the model complexity to include all frame elements and the spindle. As the geometry increases in complexity, I imagine the results will be less and less representative of life, but as previously mentioned, this is not what I do all day, so plod along I shall... Load applied (1000N) on the spindle taper.
In X direction (machine long axis) :
Stiffness
In the Y direction (gantry direction):
The Z axis assembly is the greatest contributor to deflection, so it may benefit from a redesign at some point, I will fiddle with a flange on the bottom to counter the plate cupping, or look at a thicker backing plate/ some sort of bracing inside.
Final stiffness in the x direction came to 13.94N/um
Final Stiffness in y direction came to 34.85N/um
Even with the flimsy base and x rails in the y direction, the compliance of the z axis in the x direction makes it the weaker direction by a significant margin.
That being said... even the 13.94N/um is more than stiff enough for Ali milling. I suspect the machine will perform OK