I just purchased a used die filer from a retired tool and die maker this past summer. It does not have an overarm, but it runs at a nice speed, right around 200 or 250 strokes per minute. It uses a small gear motor and a belt to drive the filer. It cuts on the down stroke like all filers should, but can still lift the part off of the table if too much pressure is applied against the file. I learned in a hurry how to keep my fingers in a safe place when using it! I have not yet decided if I will attempt to make an overarm for it, but there are times where it might be nice to have.