Join Date: Dec 2011
Location: Morris County, New Joisey
I haven't seen enough drill press bases to know how the columns are attached, but I'm wondering if it's pinned to the column through a hole somewhere in the side of the base casting. Or maybe a setscrew?
I'd add my vote for a long soak with penetrating oil. Several days, a week, or whatever. And give it a daily beating around the base, as Woodnthings suggested to see if that helps loosen it.
You mention a ledge in the base that the column sits in. Looking under the base, can you see any of the wall of the column, or does the ledge completely cover it? If any of the column sits inside the ledge, maybe you could cut a steel disk the right size, then whack it with a block of wood & a hammer?
(Got any pictures of the situation?)