Ball Crank Handle on Heavy 10 Cross Feed

Gentlemen -
While using my Heavy 10 yesterday the nut and round key that holds the ball crank on the cross feed shaft came off and landed on the floor among the chips I created earlier. I was able to locate both of them and reassembled the ball crank to the shaft. If I tighten the nut so that it won't come loose the shaft is difficult to turn. With the nut loosened up so that the shaft turns freely the nut is somewhat loose and I believe it could come off again at a later time. I have looked at the repair manual and the parts manual with an exploded view of the assembly and I do not seem to be missing any parts. Has anyone else encountered a similar situation? Thanks in advance for any advice or comments you might be able to offer.
Taildragger

you obviously need a new lathe.

kidding...check all the parts for a burr,ding,embedded chip.