Depending on the length of the slot, can you just drill two holes very close together then use the file to break out the wall between? If the slot is less than twice the diameter of the bit, I don't think it would work to drill a second hole as the bit would want to walk into the other hole.
-- Blue skies. Dan Rossi Carnegie Mellon University. E-Mail: [EMAIL PROTECTED] Tel: (412) 268-9081
