Heavy sewing thread, carpet or button thread, cotton polyester or polyester. Try to use thread that's not slippery through the fingers. Practice with a sandard double knot to arrive at the correct length & tension. Then cut the thread, measure its length, and start again with a fisherman's blood knot. This circulates without pinging. After careful tensioning, you will hear improvement using thread on both spans from flywheel to platter and from motor to flywheel.