Need advice on gantry design

[EddyCurrent]

Consider the information here; http://www.cncroutersource.com/do-it...NC-router.html
That should be a guide to the best arrangement.

There was some discussion here about "stiffness", it's a pity more people did not contribute at the time. http://www.mycncuk.com/threads/7155-...stiffness+test
There may be some merit at looking at the numbers to see what each design offered.