I think its being redesigned and is currently unavailable see the phlatprinter store page- http://www.phlatboyz.com/Phlatprinter-3-Kit_p_9.html
Its still in the works at the moment, but you have the right idea - low cost and easy to make. It will be open source once its posted Mark and Trish
Any news? Will the mk4 be built on the V-slot design? I'm in the planning phase of building a CNC router, would be good to know if the MK4 (kit or plans) will be available within the next 1-3 months?