Benchtop table loading

[rhfurniture]

I have a (recent) prt benchtop and think it is wonderfull. It works well.
I noticed that one of the running (vertical) rollers on the Y carriage was out of alignment, and the holddown rollers (horizontal) are tight at the ends/loose in the middle (must exercise it more). As the Y mechanism is under the table I will have to strip the table off to align and adjust.
My question is how much can I load the carriage - I bolt jigs and spoilboards on and nail into it with an airgun. Long stuff I support with rollers. I do not want to start bending the metalwork underneath.
I would like to strengthen it if possible, and change the hold-down bearings so they are easier to adjust - could I spring load them?
Any suggestions welcome. It is working ok, but I want to keep it that way.

TIA

R.

[rhfurniture]

Hey,
All you benchtoppers out there..
I would really welcome some exchange on how much loading it will take. I really do not think that a 8ft x 4in x 2.5in doorstile clamped on to the y carriage to do the top mortice would leave its sense of level unaffected, with the rollers only being 12in appart. (well, even I can see it needs support). Also it is very unaccessable for adjustment. Has anyone tried beefing it up, widening the roller span etc etc?

Regards to all,

Ralph.