One interesting point … mentioned in the text under that You Tube Video
The availability of [very] long beds and cross-slides. 
That's a significant advantage of using extrusions … I wonder if they are available individually ?
MichaelG.
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The availability of [very] long beds and cross-slides. 
With a nod to Michael Williams' comments on the Metalmaster thread … obviously there would be terrific problems with alignment at those distances … but it would be very useful raw material.
Edited By Michael Gilligan on 08/08/2012 07:43:16