All steel, no welding, 2000x1300x250mm

[Wal]

>That's right :) They will be supported at intervals.

Ah, okay. You'll need to keep a close eye on those creeping bearing housings then, if one of those housing edges were to catch on a support it could spell trouble, although you'll probably hear them knocking/scraping before it does. Bear in mind that the machine could be working on a small part of a project, going back and forth many times over (with the bearing housing silently creeping out of place but not having to pass a support strut...) before moving on to a different part of a table... If it's crept enough to catch on a support strut... Disaster.

You might want to 'arrest' the housings so that they don't rotate past a certain point, ie. with a blob of epoxy - I don't mean for you to glue 'em in... Just a blob or two on the outside of the housings that stops them rotating past a certain point... [I should probably do the same with mine...]

Wal.