If you have broken a needle, you most likely have a burr on your hook somewhere. Burrs cause frustrating top thread breaks. Many times you’ll actually hear the “pop” as the top thread breaks. All longarmers should have some of this specialized sanding cord in their longarm tool kit. The soft abrasive is similar to 1500-2000 grit and good for fine hand-polishing of soft nonferrous metals. These cords slip into areas that other forms cannot, such as small holes, narrow slots, keyways, and grooves. Make sure you give your machine a bath of WD-40 and oil it after you’ve worked on it with abrasives and be sure NOT to sand the tip of the hook. It must stay sharp and stay at the original angle.