getting around to starting to fabricate approx 60"x60" router and could use some feedback on my thoughts for the Y axis. my plan is to use 1" black pipe with connecting support between 2 pipes spread apart approx 6-7" and use skate bearings top and bottom in a 120 degree layout on the four corners of my Y/Z slide. my concern is how well this layout will function with working torque from X/Z axis. I attached a rough pic of layout. my fear is that the whole unit will be to easy to rotate with the round pipe and almost circular bearing layout. the spread of the pipes I'm going to try to maximize and make bearing carriers adjustable.
Looks almost identical to my construction. I used drill rod instead of black pipe. The first problem I ran into was that the Z carriage tended to troque and twist/bend the X carriage. I did a mod by adding a "torque tube" to the back side of the X carriage. The torque tube is 2" dia aluminum clamped to the X carriage with some fabricated aluminum clamps. The tube keeps the assembly from twisting/shaking while routing. Mine is just a 26" X 26" X 9" table, so with 60" I would imagine you will run into the same issue.