Thanks...yes I think building a cover is the best bang per buck approach to keeping your cutting rate/strength high, but noise low - I'd like to have seen a photo of your acoustic shroud ...any chance?

I've gone full circle, and will actually buy the Walter/Borsh 4030 CNC http://sites.google.com/site/cncdiyorg/4030 (it has 1605 ballscrews *& can take a VFD water cooled spindle) ...there are youtube videos showing it cutting aluminium too ...so that'll do for me - only one problem - the seller isn't responding to emails!