Ok Ive altered the design to put in some registers (In Red) and opened the channel to allow for a standard 1605 ballnut bearing seats are all now standard as well Im going to transfer this lot to V0Carve and run the simulation to see if i get any surprises. All the bearing and ballnut mounts are now seperate and adjustable, there is ample access for Lubrication as well

Click image for larger version. 

Name:	backplate rev5b.jpg 
Views:	561 
Size:	297.3 KB 
ID:	7865Click image for larger version. 

Name:	backplate rev5.jpg 
Views:	562 
Size:	278.9 KB 
ID:	7866

You can only see one side of the registers but take my word for it they are there..

Rick