One ring to rule them all?

[Rufe0]

RE:routercnc
The problem with a machine where you move the work around is you loose working area. Although that machine looks great it only has a working area of 500x500mm.

I was thinking I would have a 5axis head attached to a normal xyz gantry machine like this http://www.5-axis.com/.

I'm thinking of designing the gantry like this, cross section

The Z axis would probably run down the middle.

Anyone know how to work out the deflection? I'm thinking If you had a load of 100kg at 1m thats equal to 333kg with a separation of 300mm. Then calculate the bending deflection of one beam with 333kg, then multiply that by 3 to get the deflection at 1m.

To be clear I was thinking the frame would be 100x100x5 and the gantry 200x100x8 but only because those where readily available sizes. If I have to special order some bigger then so be it.