Quote Originally Posted by m_c View Post
It would mean that when you're machining on the base, the cutter would effectively be working below the x-axis supports, but the higher rails should improve ridgidity.
Yes, that combined with a bed which you can adjust the height of is by far the most rigid way to do it. As there are effectively no gantry sides you have eliminated the flex they cause. You can make the rest of the frame as heavy, and therefore strong, as you want as it is now stationary. I changed my router to that configuration and it has made a huge difference:

http://www.mycncuk.com/forums/showth...ll=1#post22767

It is interesting that you seem to have profile rails yet cannot afford ballscrews? Is that because you spend all your money on the rails!