I've got a Delta 16 1/2" drill press and the spindle adapter keeps dropping
out. The surface of the tang on the adapter is clean and it appears to
wedge firmly up into the unit but invariably it will drop down during usage.
Makes no difference, light or heavy drilling it keeps falling out of the
unit. Not only a big bother but it can be dangerous.

I thought about using a mallet to knock it into place but am a little leary.
Any ideas on how to get this to stay put ?

Thanks,
Ed