BK12 end float?

[Jonathan]

I guess this clarifies why John S told me he doesn't use the BK or BF bearing blocks!

I don't use them either - so far I've not seen one that didn't need a bit of TLC to remove the endfloat or other problems. I much prefer to spend a bit of time making my own so I know it's definitely accurate.

Hmmm, the plot thickens. Made some shims for the outer races and still have end float. With the bearings on the ballscrew, not in the housing and the lock nut tightened fully, the outer races have around 0.3mm of play in them...so no matter how solidly fixed the inner and outer races are, the play is in the bearings themselves. Am I missing something here, or is it the "china" bearings that are crap?

Are you sure the bearings are in the right way round? Are you sure the spacer Jazz mentioned is long enough? The bearings rings shouldn't be a tight fit. Either way if you look carefully you should be able to see the part that's at fault... can't really give a more precise answer than that.

I wouldn't use Loctite as how can you properly preload the bearings if an adhesive is holding them?