Originally Posted by
JAZZCNC
That's most likely to be alignment issue not sticky seals. To be honest I've fitted 100's ballscrews and never had sticky seal on the ballnut(presume you mean ballnut seal)
Now what can happen is often the spacers on the BK bearings are not long enough and the seal in BK bearing can rub on the screw.
This tends to happen mostly on cheap BK bearings. Also on cheap BK bearings, like what Chai Sells, the bearings are not always shimmed correctly or even in wrong way round so when tightening the nut they will bind.
Joe If BK's came from Fred at BST then you can tighten them fully and they won't bind. Fred BK bearings are light years better than Chai's.