1. Cut a piece of thread with appropriate length, split it in two on the stringed erhu string, and fold it in half.
2. Select one of them as the uplink, and the outer one selected here is the uplink.
3. Step 1, wind the selected upper thread around the piano rod and tighten it.
4. Wind the rising wire that has been wound around the piano bar for another week, and keep it tight.
5. Repeat the previous actions. The ascending line winds the piano rod first, then the string, then the rod and then the string, and repeats mechanically.
6. Then, the remaining length of the uplink line is appropriate, and the end of the line is inserted downward between the polar lines.
7. Then tighten the upper thread at the bottom.
8. The effect after tensioning is shown in the following figure:
9. Finally, tie the two long lines together, and the erhu will be tied with one thousand kilos.