To smooth the channel walls on small channel settings, a roller can be made from an old millgrain wheel. Carefully grind away the metal ridges that form the beads, leaving a smooth channel around the outside of the wheel. Then, polish to a high shine. Place this modified wheel in its handle and roll it over the top of the channel wall in the same manner you would use to millgrain an edge. The result is a smooth edge of metal burnished tight against the stones. This modified millgrain wheel works equally well on bezel set stones.