? ?I have been working with ballscrews and ball nuts for 50 years. I first leaned that if the balls come out of the ballnut it is a real problem to fix. I had my first disaster? while working in a shipyard installing a automated new torpedo handling system on a submarine. While testing I overran one of the ballnuts and the balls came out. Fortunately, the balls fell into a cavity where they were easily removed.? The ballnut had the recirculating return tubes that were removable so I was able to put the balls back in and that fixed the problem.
? Unfortunately, a couple days ago I was working a a dyna mechatronics Y axis that I had retrofitted for a P7 precision ballscrew with a double anti backlash ball nut. After I had the Y axis assembled? I? wanted to see how well the mechanism was working. In Mach3 I had pressed the tab key to bring up the MPG. My monitor for some reason doesn't show the LEDS for the jog mode. I did not realize that it was in the incremental mode and that mode was set to 10.000. When I clicked on the Y + button the Y axis flew passed the ballscrew to the extreme and beyond the ballnut spewing the balls out. The ball nut does not have a removable recirculation tube and are sealed from the factory. I uttered a several of choice words I learned in the shipyard.? The good news was that I had ordered a spare ballnut because the ballnut flange is round and I had to grind a flat on the the top and the bottom for clearance with the base and the Y axis. I would have to keep spraying the ballnut flange with water to keep it from overheating and I so I was glad that I had ordered a spare. I ground the top and bottom of the replacement? ballnut flange and installed the ballscrew in it and reassembled the Y axis this time adding a positive stop on the Y axis and now have it working properly and with limit switches.??