[microdot]

For a CNC plasma table is there any functional difference between a linear bearing or a linear rail?

Linear rail being the supported round bar with pillow blocks vs linear bearings which have flat sides.

[schbrownie]

Yes, there is a difference between "square rail" (profile rail) and "round rail" (shafting + bearings)

Because this posting could go on forever about the difference between the two, can you please tell us what level of precision and repeatability you need/want to acheive with your system?

Keep in mind, that as the level of precision gets higher, the price also goes up (exponentially)

[microdot]

In this application, precision is not particularly critical. I plan on using this for a 4 x8 plasma table I want to build. As far as I'm concerned, I just want something that's more precise than the V. rail I see alot of these projects using.