Abstract: In order to reduce the yarn waste in the next process, a yarn length measurer controlling single spindle in the cone winding machine was designed. Two Hall sensors were used in this machine. One was installed on the principal axis of slotted drum which tested the revolutions of slotted drum, the other was installed on the cone which tested the actual revolutions of cone. The linear velocity slip rate between the slotted drum and the cone was calculated by comparison according to the revolutions of slotted drum, the actual revolutions of cone, the diameter of slotted drum and the instant transmission radius of cone when the actual revolutions of cone was added up to a definite value. According to the linear velocity slip rate, the yarn length of cone was calculated and added up. The cutter would cut off the yarn when the yarn length of cone reached the inputted value beforehand. This device could be used in the design of new kind of machine, and in the rebuilding of old machine.

Key words: length recorder, hall sensor, online test, linear velocity slip rate, instant transmission radius