Hi All


I am considering building a gantry type cnc vertical mill. I am trying to decide if I will go for a moving table or a moving gantry. I have read that the moving table is less "efficient" in terms of space usage, my question relates to this.

All the moving table designs that I have seen have the long rails on the bed and short bearing blocks on the table, i.e. bed length = table dimension + maximum possible travel.

However, in a standard vertical mill the opposite arrangement is universal, i.e. The table is on top of the saddle and the table dimension is longer than the saddle, overhanging on both sides, so the equation is changed around to be: table dimension = bed (saddle) length + maximum possible travel.

So my question is this: Would a moving table gantry machine with table overhanging the bed for a significant portion of travel be a really bad idea?


Thanks

Hubert