I bought the small X-carve CNC mainly out of curiosity. I already own a CNC shark and Probotix Meteor. The X-carve and its belt drives gave me pause as even after I tightened them up I could move the gantry enough that I abandoned it and haven't used it. I'm currently using the stepper motors from that kit for a plywood CNC I'm building. Ball screws and linear rails on all three axes.