I have been designing this one for a while now, so this first post will be a sort of catchup, showing the various design changes that have happened along the way.
Original version.
This had a fixed gantry and a platform that could move in the X and Y planes.
Version 2.
Still had a fixed gantry, but has the X and Z planes on this gantry.
Version 3.
This makes use of some of the linear slide items I bought from Ebay, but is still somewhat incomplete as a design.
Version 4.
More use of the linear slide items (I bought a few), and a more sturdy sub frame.
Version 5.
A more minimalist version that draws on some other ideas out on the web, most notably John Kleinbauer (unfortunately now removed from the web).
Version 6.
Not a huge amount of variation from the previous one, some of the bracing has been removed.
Version 7.
Re-designed again, this time using Unistrut as the chassis.
Version 8.
Back to a gantry design, but using Unistrut, again, an incomplete design.
Version 9 (Current version).
Loosely based on one of Microcarve‘s designs, using MDF and threaded studding as the chassis.