User cvoinescu made the following comments on Upgrades in the forum thread Custom Plates:
In my opinion, this is the decreasing order of effectiveness of the modifications:[list] [*]Dual Y drive[/*] [*]Dual X rail[list] [*]X carriage reinforced with, say, extrusion between the two plates, instead of relying only on the X wheel bolts[/*] [*]the two X rails 20-30mm apart and rigidly coupled together, e.g. sandwiching between them some standard extrusion and bolted together along the length[/*][/list][/*] [*]Moving the Z wheels further apart, i.e. replacing the standard plate with a taller one[/*] [*](for a long machine) Mid-span supports for the Y rails, and/or doubling it with standard extrusion bolted along the length[/*] [*]Moving the Z leadscrew to the side to reduce the length (and hence flex) of the Z wheel bolts[/*] [*]Thicker plates[/*][/list] I'm not sure about the order of the last two items on the list.
Now if you somehow got your hands on hard-coated MakerSlide and replaced the V-wheels with steel ones (difficult, as they aren't available in the same diameter as the plastic V-wheels), it may be worth reinforcing the plates.
That last is much easier now w/ Openrail.