The Glebar GT-610 Series of infeed/thrufeed machines as well as the Glebar GT-9AC machine, used for grinding medical components, are available with a variable frequency drive on the work wheel spindle for increased wheel surface feet when running super-abrasives such as vitrified CBN. Spindle RPM can be varied depending on the wheel type and wheel dressing parameters. The GT-9AC has proven to be very effective running vitrified CBN wheels reducing cycle time and increased setup life over conventional abrasives on a variety of different materials, the GT-610 series is equally as effective for many different applications.