Are you using left-handed bits? That way if it drills, fine. If the
bit grabs and tries to turn the screw, fine. The drill pulls the
screw out more often than you might think. If you're worried about
staying centered, maybe make a block with an appropriate sized hole to
help guide the bit?
--Glenn Lyford


Never had or tried left-landed.

You know that had crossed my mind, but when I read it, it occurred to
me that I could bolt a guide onto the top of the platen/table and have
it 90 degrees downward, drill through, and that all the screws should
be at the exact same plane.

That's a great idea, thanks. Best start looking for some metal that
is 90 degrees on the inside.


SW

I was going to suggest left hand drills also. They are my GOTO
solution for nearly all stuck fasteners. In this case, you'll have to
make up some sort of drill bushing/guide to get as near center as
possible.

Karl