I converted a 1340 over to cnc with a homebuilt system using geckos and Mach3.
It worked ok but not great for mill work.
I also machined ball srews and converted the screws to ball screws.
As a lathe not bad,as a mill not that good for anything more than plastic and aluminum.
I have some pics on my website here:
http://www.hitechhobbies.com/Machines.html
Good luck with your conversion.
I ended up buying a Bridgeport Series II cnc and an Emco lathe.