I've found the cutter fine for norml sized ceramic tiles (having coped with the water etc) but I am having difficulties in cutting 310x450 limestone effect tiles (padova from topps) without badly chipping the surface. I've tried cutting with both sides of tile facing up and get the same chipping effect. Could this be the disk becoming worn, or a possible fault with tiles or just user error ?? I thought the grout would disguise the chipped edges but it looks c**p. Any ideas ??