I built a momus 2.1 last year (2015) in about 5 months. It's 42" x 36", dual motor x-axis on based Mac's Momus X2S ' modifications.
Youtube slideshow
https://www.youtube.com/watch?v=z8Mn5alhQeg
Superpid controlled Dewalt router
https://www.youtube.com/watch?v=Dm95XYNe9ks
Enjoy
Chelsi