I have a THK 3210B ballscrew off a turret mill X-axis in pieces for cleaning.
The balls are 6.365 mm (as measured with a precision DTI on a test stand calibrated against precision blocks) and pitted, so need replacing.
After cleaning, with the screw vertical and lubricated with ISO 68, the nut will rotate by gravity end-to-end.
This amount of free running seems excessive.
I have seen videos that demonstrate the nut stopping in a couple of revolutions after a manual spin initiation.
I did a trial load of 6.35 mm balls (1/4"), the nut drops under gravity when dry.
What size then should I purchase ?
I am in Sydney and 110 balls of 6.370 mm from a reputable supplier in the US will be about AUD 200, a significant amount.
Can anyone comment on the effect of increasing ball diameter by 5 micron ?
Should the increase be less ? or more ?
John