A little bit of progress. Waiting for my router to arrive so I can trim my boards to size. Should be tomorrow....hopefully. I'm cutting with a hand saw to withing 2mm and then trimming with the router.

Here is the updated sketchup 2D.







Due to the cost of ballscrews, and me not needing speed, I think I'll be going with TR10x2D trapezoidal screws from Merchantdice on Ebay. He has a set of three 700mm lengths for about £20.