Tools:

Carving knife (5mm wide, 2mm thick, one end slanted and one end flat), thin tweezers, cotton yarn, hard paper, adhesive tape for elementary school students.

program

① Install the violin on a shoulder rest to prevent damage to the backboard. Turn the right sound hole towards yourself. Lower the first and second strings of the violin by one and a half to two notes.

② Based on visual inspection of the distance and inclination of the panel and backplate at the installation of the sound column, and the needs of the experiment, grind the sound column into different lengths and end faces with different inclinations. Grind some of the end faces of the sound column into a vertical plane.

③ Use a pencil to mark the slanted side of the sound column (which should face the right sound hole after completion). Make the marker face yourself and tie the yarn on the left side of the sound column.

④ Insert the cotton thread towards the marked side through the left sound hole, blow it towards the right sound hole, and insert it with tweezers. Insert the sound column into the left sound hole. The 9mm sound column used for testing must be inserted through the circular hole on the sound hole head.

⑤ Manipulate the cotton yarn on both sides of the sound column up, down, left, and right, adjust the upper end of the sound column to the appropriate position, and make the lower end of the sound column face the left sound hole. Due to the tension of the cotton yarn, the lower end is raised.

⑥ Gently use a carving knife to move the lower end towards the right sound hole. The point where the lower end of the sound column touches the back panel without exerting force, I named it the "initial contact point".

⑦ Measure the distance from the inner edge of the left sound hole to the bass beam with a piece of hard paper, and then measure the distance from the inner edge of the right sound hole to the sound column with a piece of hard paper. Manipulate the cotton yarn to make the latter equal to the former, in order to achieve left and right balance.

⑧ Use the flat end of the carving knife from the left sound hole to forcefully push the lower end of the sound column towards the right sound hole, making the sound column vertical. At this point where the lower end of the sound column touches the back panel, I named it the "final contact point" (also known as the "foot drop").

⑨ Use the sharp end of the carving knife from the right sound hole to move the sound column about 5 millimeters away from the back panel. If the sound column does not rotate, it will be fine. Observe whether the sound column is properly installed from the left and right sound holes, as well as the circular hole in the direction of the fingerboard.

⑩ Temporarily raise the strings by one note and wait for one or two days before returning to standard pitch.