My work in progress...

[mrmz]

I joined the forum a couple of months ago and it has taken a lot of reading from you all people to get my CNC Router going on, thanks to all who are sharing their experince here...
I just got some aluminum parts finished and plan on starting the mechanical assembly tonight, just wanted to share a rendering of my future first CNC router and post a couple of questions...
If you look at the rendered image, the green round bars are balls screws and have a bearing block (Thomson brand) at each end, from what I have read it seems that I should only be using one bearing block on one end and a simple bearing on the other to allow the ball screw to expand, is this true or can I leave both bearing blocks in there? And the second question, Should I have put two ball screws per axis? I guess it is a little late, and I will find soon if this machine works or not...
In general, the machine would be 24" wide, 36" long with a z-axis travel of about 7".
I am using round steel bars with pillow blocks to guide the router carriage. The long y-axis has 1" round bar, the x-axis and z-axis have 3/4" round bars.
Other than that all the construction is aluminum, the rendering does not show the servo motors nor the z-axis ball screw, this one I obtained from a scrapped EDM machined so I suppose it is a ground precision screw and expect to obtain a very good resolution from it.
The router mounting plate will take one of those adaptors sold by K2CNC which I already got in the mail, the router would be a Porter Cable 75182.
I will post some pictures as soon as I get a significant progress on the assembly, and also I suppose that would be the stage were most of the questions will arise. Hope to get some help there...
I can't wait to have it finished...