Well I have had my X3 with CNC Fusion Deluxe ballscrew kit for quit some time now and I am very pleased. I keep having backlash issue with my Z axis but never caused to much of a issue. As I get more versed in machine work and do more complex projects it is starting to become more of a issue. I measured it the other day and I had .030″ backlash, and that was unacceptable to me. I worked very hard trying to get the collar tight and best I could do was .009″. I could see the collar and screw physically moving, so I know that was my issue. Come to find out the new Dexluxe CNC Fusion kits do not have a collar, they have a nut so you tighten it up and remove any play. Well after a email to CNC Fusion, and I got my answer. They offered to remachine the end of my ballscrew and send me a new pulley to fit for $15 shipped to me. Wow, how can you beat that for customer service.