take a look at that.
About the Z axis, I suggest that it gets built just as rigid as X and Y.
Other than the funds, the only thing stoping me from building a 5 axis machine is: how on earth do I program it without spending $15,000 on mastercam or similar
It woudl be possible to make a mini mill like mine into a 5 axis machine, put a rotary table on the xy table and a rotary table behind the head, The way to do this would be to mill dovetails into a thin peice and fix it to the back of the rotary table and attach the front part of the head to the front side of the rotary table. The head comes apart into 2 peices, the back peice(dovetailed peice) is close to 3" thick I think.
machines with more than 3 axes intrest me quite a bit, programming them is another story.