300mm? That's only ~12 inches (for those of us in the USA) and that's not particularly huge, at all.
Considering what you want to do, building models of cars, will 12" be enough?
I'd had a thought, a while back, of *hanging* a gantry router from garage door tracks, to potentially provide Z axis clearance on the order of 2.5 - 3m! You'd raise your working surface up towards the hanging mechanism, to define the Z axis working volume to whatever you'd need, by placing an adjustable height table beneath it.
Of course I never built it, but it seems like it should work...
-- Chuck Knight |