My balls also make a rattling sound. Err...I mean nuts...that should be ballnuts.
I think it is the balls entering an running through the return circuit. And this is new
quality nuts like THK and Star.
Preloading low quality nuts will not be the same as nuts made preloaded. It's the same
as preloading a standard ball bearing, it will increase the wear because the balls are
riding up against the side. When made for preloading the right shape is ground in to
make the balls fit the groove when loaded. Some are preloaded by using oversize balls in a nut that is not split.
You can minimize backlash by mounting 2 nuts like you do, just don't overdo the preload. When the backlash is small enough to not be a problem, your preload is high enough. And don't forget that there is no use having a screw+nut without backlash if the end bearings have backlash. |