Hi, I remember how skates were sharpened by our skate shop. They used a conventional bench grinder which had wheels that were contoured to the radius of the skate blade. Guides were mounted in a suitable position to allow the skate blade to remain in the center of the wheel and the blade was run up against the rotating wheel several times, letting the weight of the skate supply the pressure. A fine grade wheel would be preferable to give a smoother finish. If the skates are figure skates, remember to take a little off the toe rakes to prevent them digging in as the blade will have been lowered in relation to the rakes. If my explanation is not clear enough, come back to me and we can discuss it further.