I have just completed the set up on a new Standard 96x48 with a 4hp single ph spindle. When I initially was able to move the machine around with the keypad it ran pretty smoothly without any sounds I wouldn't expect. But...at the point of starting into spoil board surfacing bad sounds and vibrations have arisen. The surfacing process started normally and about half way around on the second pass the vibration and noise started. I have adjusted the the pinons from quite tight to quite loose with similar result and there looks to be ample grease in the rack/pinon. As you can see from one of the video clips, when I pulled the motors from the gantry and ran them they run smoothly and quietly....maybe more quietly in one direction than the other but certainly smoothly. I've tried moving the gantry squared up and not squared up with the same result. So, I am at the point of being out of options to try based on my limited experience. I have attached three video clips with sound and am hoping some of the really experienced SB'ers will have time to take a look. I'm really afraid to run the machine for fear of snapping a tooth off of the rack or pinion....it's really that bad.