Humm, not much i can added really. When i designed my machine i gave myself enough "room" to work with material of a max hight of around 100mm with about 70-80mm travel on the Z, the machine was designed for working with thin sheet materials.

I thought that i should pay attention to keeping the X axis center as close to where the cutting action was taking place as i could, as was the same for the other two axis's, i've seen a number of diy machines where they seem to have made the z axis longer/higher/taller (whatever) than would ever really be needed, some having 200mm + travel and then dumped it on an x axis so far away from the Y that i really couldnt understand the point of having such a tall Z?

I dont know, but i was under the impression that we should be trying to keep the cutter as close to all axis center's as we can, Dean ?

.Me