Thanks for the replies, I can certainly say the ballscrew works with a ballnut. As you said Robin, the wobble doesn't mean much as the ballnut is fixed to the axis plate and the plate is guided via linear rails. The locknuts used on this are SKFs, I haven't tested them for precision, but the wobble also happens on the big bearing which is held with a cap/bolt. This is why I don't think the wobble is caused by how the bearing is held down.

I guess this is normal as Mike said, I'll just use them and not worry.

Regards,
dsc.