Quote Originally Posted by CharlesJenkinson View Post
400mm Z will probably be an acceptable compromise - I'm wondering if this can be achieved by a bed that can be removed/lowered (a head in hands moment), so the gantry doesn't have to be high up for the majority of (panel) work or the Z working at the bottom of the stroke - is it possibly for the bed to be in the middle???, so the split is 200mm above the table, plus another 200mm below when table is removed.
My machine has a Z-axis with 400mm travel and the bed height, so you might want to have a look how I did it in my build log:
http://www.mycncuk.com/forums/gantry...html#post35482

The frame/X-axis is OK, but don't take too much notice of my gantry as there's plenty of room for improvement there.