Null result for the weight change of a spinning gyroscope

A null result was obtained for the weight change of a right-spinning gyroscope, contradicting the results recently reported by Hayasaka and Takeuchi. No weight change could be observed under a variety of spin directions for rotational frequencies between 0 and 2.2×10⁴ rpm. Our limit of -0.025+/-0.07 mg is more than 2 orders of magnitude smaller than the effect reported by Hayasaka and Takeuchi.