If mass will help you then add some mass.... Torque it down to a piece of 20mm thk A36 plate 900mm x 350mm
The places where mass will help as regards rigidity, are in the "U" that is comprised of the headstock (and its component parts), the bed beneath the headstock, the bed between the headstock and the carriage/saddle/cross slide/compound(or top slide if one is on my side of the pond) and finally the carriage/saddle/etc.
Obviously the width of that "U" will depend on how close to the chuck you're working at any given time and the tailstock can be added to that "U" to make it a "W" but ultimately, the rigidity of a lathe is, by and large, determined by the parts of the lathe mentioned above.
Given the Warco WM180 has almost double the weight of the Warco mini latge models, it seems likely that the WM180's "U" will have more mass and thus more rigidity than the mini lathes.
Bolting the lathe down to something that's good at damping vibration,
might help
a bit to attenuate that feedback cycle that amplifies chatter
. It's unlikely to make a significant contribution to the rigidity of the crucial parts though.
Bolting a lathe down to a mild steel 6mm plate, which is then bolted two two steel cabinets made of 3mm plate, seems to make the feedback cycle worse, or at least makes it sound a lot worse!
Ask me how I know, and whether I've got used to hearing something that sounds like a cow being tortured when I make mistake with DOC or speeds and feeds, and whether the offcut chunk of kitchen granite worktop I'm waiting for, has had its holes drilled yet!
