I know that most operators of sewing machines newer use instruments to measure the thread tension. They have learned some way of feeling the right tension. But perhaps a few in this forum actually do measure their bobbin thread tension. I often change thread size in my machines, and I use a spring dynamometer to adjust the bobbin tension every time. I measure it direct from bobbin case or vertical up from the needle plate hole. You can get specialized instrumentation for sewing machines, bu