Cubic work-area CNC design with rigid Z-axis

Hi,

I’m considering building a 3-axis router (later to me augmented with a 4th and 5th axis head), with a cubic work area; something close to the 5 axis maker (home). I had originally planned using 1m X 1m X 1m v-slots rails. The perennial issue is, of course, rigidity with the cantilever effect on the Z-axis (Ideally, I would be able to work on wood, slow speed is not a concern as this is for hobby purposes).

To make the design more robust, two potential solutions come to mind:

1. Use the same design with 4040 v-slot rails everywhere for extra rigidity

2. Instead of having a “hanging z-axis”, have the spindle connected (almost) directly on the y-axis rail. The y-axis would then be moving up and down along two z-axis rails located at either end of the y-axis rail. The design should workaround the cantilever effect but would be significantly more complex (7 stepper motors vs. 4, for starters).

Since I am completely new to the field, I would welcome you expertise/comments about either approaches and if either/both are workable to use on wood.

As a bonus question, is there a software I can use to simulate the rigidity of both designs?

Thanks!