Measurements of Violin Bows Using an Automatic Bowing Machine

Open Access
Author:
Nadig, Clare Grace
Area of Honors:
Mechanical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • John Stephen Lamancusa, Thesis Supervisor
  • Zoubeida Ounaies, Honors Advisor
Keywords:
  • bow
  • violin
  • frequency response
  • FFT
  • stringed instruments
Abstract:
The majority of research performed to date related to stringed instruments has been focused on the violin body itself, while very little study has been done on the violin bow. This project seeks to partially fill this gap by investigating the connection between the mechanical properties of bows, such as stiffness, damping coefficient and frequency response, and the vibration they induce in a string. Another goal of the project is to determine the physical properties in a bow that produce the most desirable sound. This project uses a mechanical bowing machine to provide a consistent bow stroke and an accelerometer and a force sensor to measure the vibrations produced by the bow. Tests completed so far show that the repeatability of the data needs improvement, and that the factors that cause the most significant variation include the distance from the bridge to the bow hair and the tuning of the string, while the bow tension has virtually no effect on the induced vibrations. A preliminary comparison of six different bows and a test performed using an impact hammer to record the frequency response of one bow are also presented, though time constraints have prevented taking enough data to draw conclusions based on these tests. The project will continue to explore other factors that could affect the repeatability of the results, such as the angle of the bow relative to the string, the humidity in the room, and the amount of rosin on the bow hair. Finally, other tests (mentioned above) that have been put on hold due to time constraints or issues with repeatability will be continued.