I think the bed is far from the weakest link in the machine.

First you should replace the nylon nuts that fit to the threaded rod. This will give the moving parts more resistance against moving from vibrations and cutter backlash. No I don't know where to source these but if anyone does please let me know!

Secondly, if make sure the cutter spindle is one of the 800watt items rather than the air-cooled 200watt items (mine has). This should significantly increase the machines capability. http://www.ebay.co.uk/itm/0-8KW-WATE...t_12533wt_1052