One ring to rule them all?

[Rufe0]

I may have misread this but the two rails under the bed seem to give total support to the outside edges and none in the centre? As most of the cutting will actually tend towards the centre do you think this is a good idea?
I have never quite figured out the optimum separation but there must be one

Mmm as pictured the bed would be made of 100x100 square hollow section so shouldn't flex too much. However liear rail is cheap so wouldn't hurt to add one in the middle.


Just doing the numbers, using 100x100x5 shs @ 14.7kg per meter. The traveling 0 shape fixed but moving gantry design reqires 4.2m of tube per 100mm width. So for a 200mm wide traveling 0 it would weigh 120kg, heavy but just managable .


The very tall normal machine of the same size would need 15m of tube which would weigh 220kg.