Thanks Jazz! Would I get away with 15mm?

I think I need to sit down and consider reducing the size of my machine. I don't envisage (famous last words) doing any large wood projects etc. A bed size of ~400mmx400mm would be more than big enough. Costs would be reduced across the board and I would have more room to manoeuvre around the machine in the shed! The biggest downside I see is that I already have THK linear rails I purchased a few years ago which would need cutting down. Seems a shame to cut them (also, I'm not sure how easy that would be!?).