Im trying to decide what type of x/y rail to buy for a laser with a work space of 1000-1600mm by 600-800mm. My choice is between aluminum extrusions with round cross section rods in groves on the rail sides(hence the term "outer slider" and aluminum rails which have a linear guide on top which has a car that rides in the side grooves.
First picture is the outer slider, second the linear guide. Question is which is better for precision. I'm sure the steel out rail is more durable but not sure is its as precise