Abstract: Dynamic balancing reduces quadrature bias in microfabricated vibrating instruments such as tuning fork gyros so that a purity of motion is achieved in the absence of any angular rate input. Balancing is achieved by ablating (74) or depositing (72) onto support structure (62) for a tuning fork gyroscope rather than the proof mass (60) itself by melting and moving material on a tuning fork beam (62). Such adjusting is advantageously done during actual operation of the gyro by laser beam application through an encapsulating transparent cover which can be either part of the chip die or an external package.