Ok
Its sunny
I have a camera
and I couldn't resist....
Now where did I put all them bolts
BTW the real Z axis is not that long.
The design philosophy I'm working under is that it needs to be tolerance tolerant. What I mean is that as all the errors of machining in a assembly (which are quite large tolerances given my lack of machine tools / mill etc) are accumulative and either you try and reduce these to a very small amount or, (as I'm doing), accept them and allow for adjustment in the design to correct them in the critical parts. The critical parts in a 3 axis router IMO are the rails and the axial runout of the spindle.... nothing else. These need to be securely held (to maintaine tolerance) in relation to each other. Thats the theory... now lets see if it works in practice.
Cheers
Mark