Hi Joe,
For the size of your machine Both the options are equally good. But as you say you will have to look at the prices & availability. But 2 Rails & 4 Carriages is the most widely used design in commercial machine building. But i consider the issue of the carriage clearance with the rail when you move the Y axis on the edge with a heavy Job loaded which will tend to lightly shake up only on heavy machining.But for your machine size i would think you can have Both the options open.Please let me know the prices.
Vishnu |