The springs hold the shafts down when the sheds are made. If there are a lot of threads being lifted and not may at the bottom of the shed, you may need to increase the tension on the spring(s) for the shaft(s) that float up. Double up the springs or work the hook at the end of the spring into the spring itself to shorten it. You may need to do only some of the shafts—for only the sheds where the shafts float up. You generally want as little tension on a spring as needed—so the shafts lift with as little force as necessary.