Many woodworking machines, even brand new machines, use unbalanced pulleys. These work great for the average woodworker, but these days woodworkers are spending big bucks on blades and knives. With these new technology balanced cutters, you should probably consider balanced pulleys for your machines. Used in combination with link belt, there will be no vibration transmitted from a balanced drive system. These pulleys are machined cast iron and are a significant upgrade to any machine for a minimal cost.