Thanks Dean, I'll have a look and see. I don't think anything is loose or falling off!! Only one I'm not sure on is how tight the square shaped nuts on the BK bearing block should be and whether they are perfectly set up. I've done the best I can, but when jogging the machine rapidly in alternating directions on the X axis it does sometime make a noise and appears to momentarily stall. I'm not sure what that's about and it doesn't do it consistently but wondered if that could be connected to differing tension on the two ball screws? I did not get this when cutting or doing the calibration tests at the weekend. I'll try and video it so you can see what I mean...